PENON QUATTRO 4 Dynamic Driver Universal IEM

PENON Quattro- Bluishly Smooth​

Penon is a well-known manufacturer of iems and cables. They are based out of China and I have been exposed to a small number of their iems like Penon Fan (I still own it ), Penon Serial and Penon Volt. Their cables and connectors are top notch as usual. They have established themselves as a store and as a manufacturer.

While Penon’s core signature comes up easily in the Penon Fan, Penon Serial and Penon Volt iems with different emphasis on different parts of the sound signature, I am excited to try this new iem.

COMING ON TO THE PACKAGING—When I got the iem, I didn’t get much; it was just the iems and the cable with no tips. I have listed out what should be present in the packaging so you can check it up properly.

TECHNICALITIES-

The QUATTRO uses an independent 3-way crossover and 3-independent conduit design for better layering performance.

• Low frequency uses the latest horizontally opposed dual low-frequency driver to enhance the bass effect.
• Middle frequency uses a new generation of graphene materials providing more rich details and listening.
• High frequency uses a new process that makes the sound smoother and more delicate.

SPECIFICATION

• Driver：4 Dynamic driver
• 1 x 6mm custom dynamic driver for High frequency
• 1 x 8mm graphene diaphragm for Medium frequency
• 2 x 10mm composite diaphragm for Low frequency
• Impedance: 16 Ohm
• Sensitivity: 100dB
• Frequency response: 5Hz-30kHz
• Connector: 2pin 0.78mm
• Cable length: 1.2M, with 4.4 Pentaconn connector in the sample

PACKAGE

• Penon QUATTRO
• 9 pairs of silicone ear tips (SML)
• Earphone case
• Pouch
• Brush
• Clip

WARRANTY

18 months warranty is a refresher as its better than a 1 year warranty.

BUILD-

• IEMS-
  
  • These are made of resin and that just shines through with the blue-coloured iems. They are light and have a grill on the nozzle. The nozzle wasn’t too big to hurt my ears. They have 2 vents which are covered with grills and also coloured red and blue to indicate the R and L iems.
  • They fit me well like a lock and key and didn’t move at all. I have averagely sized ears (I use L and ML-sized eartips).

• CABLE-
  
  • The cable enhances the iem’s presence with its complementary blue colour. I didn’t get any cable noise while moving around with the iems and they had pentaconn connector which also looks strong. The cable is heavy, but not as much as EA 8W cable.

DISCLAIMER-

The Penon Quattro is part of a review tour organised by A.G and @Penon in my country. The sample belongs to the brand. I had the opportunity to listen to it for 7 days for the purpose of this review. This review is completely based on my experience with it, and all opinions, positive or negative, are my own and no one else’s. No external factors influence my review; only internal factors like my brain and heart influence it . Please try it yourself, if possible, since we all hear things differently. If you want to purchase it, you can buy it from the official product website from the link. PENON QUATTRO

SOME CONSIDERATIONS-

Source- laptop on battery with the Qobuz beta app and WASPI exclusive and direct mode being used, and also my phone with the Qobuz app set to High Res.

DAC used - PAW S1, no Efx Mode and 4.4 pentaconn cable being used to power them.

AMP – Topping A30s (Burson v5i added) and Xduoo mt 602 with Sylvania 1954 tubes was used to test out whether it was being underpowered and what interactions do I see.

Tips used are as follows: I dont remember their other 2 names but if i do i will add it here. But i settled on the CP 100 (red stem) ones as they were the best sounding and fiiting my ears perfectly.


REVIEW-
Usually, most reviews are based on the sound profile of an iem. But I want to change the format a bit and focus on the song and sound profile so I think it would make it much easier to understand what I am talking about.
So, keeping the legendary sound range of the human ear the same – we begin from the lower end of the spectrum i.e.

BASS and SUB-BASS

The song to be focused here, is FLIP- Glass Animals – Zaba.
It focuses on the beats of the drums with a small percussion working at the same to reach the same note density (I mean the sound volume/ intensity here). It easily distinguishes the instruments even though they are tonally different.
Next, we begin something which has a lot of percussive items along with big drums (like used in ancient tribal areas)- The song being used is -Woodfall Temple (Theophany).
Hearing the different big drums along with different percussive instruments leads me to believe that they are quite tonally distinct and easily felt through the song. The big drum hits at the beginning needs to have a bit more extension in its hit but was appropriate in the body of the note of the drum.
Next we shall see something with sub-bass- Here we going to use a famous track from Hans Zimmer – Why So Serious, check from 3:29 Minutes and you would know what I am talking about.
The sub-bass even though felt but felt a bit dampened. The body is coming through but the extensions seem to be a bit lacking and the thickness is a bit less. Penon seems to be focused on quality over quantity in this iem and separation is a more important factor, but I want a bit more of the sub-bass extension and body.

MIDS, VOCALS, LAYERING AND SEPARATION-

This works together, you have most of the body of notes of instruments in the mids, vocals compete with the instruments and thus what we expect is a certain degree of layering and separation between them. Hence all need to work together to provide some degree of accuracy and musicality.
Let’s, start with vocals- For Female vocals- Midnight at the Oasis – Renne Olstead and Uninvited- Alanis Morisettee; For male vocals – Circle of life – Carmen Twillie and Aint no Mountain high enough- II Divo.

Both vocals are epic, they are quite distinct even between multiple singers. Small sounds like lip smacks also come through easily. The high notes that the artists reach, are maintained but might require a bit more height in the soundstage. Female vocalist’s ssss sounds are handled beautifully and come through really well. I love the female vocals here, they seem appropriate, and the thickness of the voice is spot-on. For Male vocals, I might require a bit more thickness.

There are many songs I went through for the MIDS, Separation, and Layering- Instruments are lovely. They have a good body and tonality doesn’t seem to suffer from multiple instruments in the sound stage. The notes are a bit on the less thick side but probably done to establish the separation between the notes as they are quite easily detectable. I love the separation on this set; even far away instruments come through (check the saxophone/ trumpets in Tonight Tonight song – going at the left ear slowly increasing in the volume). The heights of the notes of different instruments seem a bit similar, ie they aren't reaching too high on the soundstage. But don’t worry, the notes horizontal and vertical spread is great so they won't seem congested. Tonality is slightly on the warmer side to help handle the upper mids and with this, even the harshest songs will be easily tolerable. Layering on an X-Y axis is good and easily separates multiple instruments, which can't be said for the Y-Z axis and X-Z axis; even though separated, the instruments feel way too near to each other.


HIGHS-
Use TANK! (Flix Mix)– COWBOY BEPOP / Moanin’ – Tommy Igoe and the Birdland big band - This iem is for those who want a smooth experience in the highs. This iem smoothed out the highs easily yet keeps a lot of energy in them. They are quite well separated and not thick or cause ear pain on long-term listening (at least 2 hours in my case). They reach good heights on the soundstage and are not too thick. The body of the notes is average but the separation here is also something that specifies quality. This iem does separation in a completely different way. But the tonality and horizontal layering is quite good and accentuate the clarity of the items.


Now let's see how this fares with an improved cable Effect audio Ares S 8W (UP-OCC Pure Copper Litz cable)-

I would be going through the same songs as mentioned above and would give a short overview of the interaction between the iem and the cable ( I do listen to both songs on the stock and the cable being tested to compare, keeping the volume indicator nearly same unless a bit more is required to hear).

Power requirement- I used PAW S1 to compare with the stock cable. A volume indicator of 48 works well with the stock cable, but with the Effect audio cable, it’s 55, and both are being used with High gain. So, it’s a slight bit more extra notches on the volume wheel.
With external amps, it’s a slight increase in my SS amp (A30 with v5i ), but with my hybrid amp ( Xduoo mt602 with Sylvania tubes) it doesn’t require much increase.



Changes that were observed- The first thing I noticed was that the notes reach higher heights in the head-stage with the body of the notes being more enhanced. There was more presence of notes of instruments, and it was more musical. Bass felt more articulate and has good extensions. Sub-bass was slightly more enhanced. Vocals were also equally affected by being more energetic and reaching higher note sizes on the head-stage. The highs felt to have become energetic but not sharp making the music more enjoyable. A Single pull of guitar strings is more enhanced and separated (check Stampede- Alexander Jean) Nuances are also better heard among the music.

Overall, would I recommend this cable. Well as a compliment to the iem nope, but as an upgrade to the iem yes, this cable achieves the energy that I felt was a bit missing in the iem mostly in the high-end and bass extension. Even nuances are better heard so clarity takes a good raise too. I am loving this cable upgrade to the iem.

Verdict- It does vary from the Penon Signature sound that i have listened to, but this is a refresher. The sound feels matured and smooth and a simple cable upgrade makes it a much better iem alltogether. I recommend this, yes but do save for a cable upgrade or if you have good silver or UPOCC copper litz cable.

PENON Quattro: Why So Blue??​

DISCLAIMER: The Penon Quattro was purchased by us directly from Penon Audio with small discounts, we are thankful to the amazing team at Penon Audio for the same. The review reflects our honest opinions as always. However, our evaluation is based on a comparison of the price of the item.

Introduction: -

Penon Audio is a China-based company that was started in the year 201,3 by Chi Kong Hui with the goal of selling the best-selected audio products at the most affordable prices for Audiophiles. Penon Audio needs no introduction in the world of Audiophiles as most of us must have purchased something from Penon Audio in our musical journey. Although they initially started with retailing other Audio brand products, they ventured into manufacturing around 2018 with their lineup of IEMs, Cables, and Accessories. Their IEMs such as Penon Fan 2, Penon 10th Anniversary, and Penon Serial which we have reviewed already in Aural Cafe are quite famous in audiophile circles. Penon Audio IEMs come with their house sound which we can describe as musical yet with lots of details and soul.

Penon Quattro is a Four Dynamic-Driver based in-ear monitor that was launched in November 2023. When it comes to Dynamic-Driver based IEMs, in the earlier days IEMs used to come with a single dynamic driver, moved to double then to triple DD-based IEMs launched and eventually now to 4 DD-based IEMs with the launch of IEMs like Oriolus Monaccha and Penon Quattro. Well, Penon Audio was quite successful with their 3-DD IEMs, Penon Serial which has achieved a ‘Nirvana’ Status in the dictionary of Audiophiles and as a result, the Penon audio fans were quite hyped when they came to know about Penon Quattro. Quattro uses an independent 3-way crossover and 3-independent conduit (independent tubes) design for better layering. The low frequency is taken care of by two 10 mm composite diaphragm-based DDs that are placed horizontally opposed to each other for hard-hitting bass, while the mids are taken care of by single 8 mm graphene diaphragm-based DD drivers. The higher frequency is tuned using a 6 mm custom dynamic driver to achieve smooth and delicate highs.

Penon Quattro can be bought for 399 US$ from Penon Audio's official website.



Specifications: -

• Driver Configuration: 4-Dynamic Drivers per side
• Impedance: 16Ω ± 10%
• Freq Response: 5Hz-30Khz
• Sensitivity: 100dB/mW @1kHz
• Connector: 2-Pin, 0.78 mm
• Cable: 1.2 m with 4.4mm Termination

Packaging & Accessories: -

• Penon Quattro IEMs
• 2-Pin 0.78mm Cable of 1.2m and 4.4mm termination
• 3 types of Ear-Tips, 3 pairs of each
• Cleaning Brush and Clip

Check out the full unboxing video here,






Build & Design Concept: -

Penon Quattro is hand-made using high-quality medical-grade resin material. The use of medical-grade resin helps in designing a durable yet light shell that is comfortable to wear. The size of the shell is surprisingly compact and similar to the Penon Serial despite having 4-DDs on each side. This just shows the focus of the Penon Audio team on the fit and comfort issues of the Audiophiles while designing the shell. The translucent black shell helps in gazing into the complex dynamic driver setup in high-quality 3-way crossovers. The Penon Audio team has made use of 3 independent conduit designs for better layering. the electrical wires are shielded with tubes in order to achieve better layering and reduced distortion. We also feel that this also helps in the durability of the IEMs as there are four DDs inside the shell. The beautiful blue faceplate has a wooden pattern which gives a very soothing and elegant feel to the whole experience. Other than its four dynamic driver setups it's the high-quality shiny blue color graphene cable that gives the Quattro its bold stage. The cable is so attractive that even wireless lovers will come back to cable-based IEMs. The bluish graphene cable just not only has good looks but also sports high-quality connectors and splitters and comes in all 3.5mm, 2.5mm and 4.4mm termination which the audiophile can choose while ordering the unit from Penon Audio’s website. Additionally, there is a blue vent present on each shell to mitigate pressure buildup inside. We would also like to add here that the size of the shell is average and provides a comfortable fit vis-a-vis providing above-average passive isolation.

When it comes to accessories as usual the Penon Audio team didn’t compromise with anything. The Quattro comes in a standard blue leather Penon case along with three different quality silicone ear tips in S, M, and L sizes and a small leather strap to manage the cable.




Sound Analysis: -

Credits: @ToneDeafMonk

• Tonality: - The sound quality of Penon Quattro is analyzed after a burn-in of more than 200 hours as they’ve instructed on their website as well. Since it is a 4 DD-based IEMs, we at Aural Cafe made sure that those drivers were properly burned in before the review. When it comes to the tonality of Penon Quattro, it showcases a warm musical signature. The tonality has more warmth than the usual Penon house sound.

• Lows: - The low frequency in Penon Quattro is taken care of by two 10 mm composite diaphragm-based DDs which are placed horizontally opposed to each other. One needs a high-quality powerful source to extract the most out of it. The bass on Penon Quattro is full and hard-hitting if driven by powerful neutral sources. In our case, the Penon Quattro pairs really well with Aune M1p and Dethonray Listening M1. The warmth of the low frequency also plays a major role in the overall warm and musical tonality of the IEMs. The mid-bass is balanced but does take the lead in comparison to the sub-bass. While listening to ‘Heartless’ by the Weekend the mid-bass hits decently hard while remaining buttery smooth across the frequency. When it comes to Sub-bass the Penon Quattro does have sufficient quantity but lacks in quality.

• Mids: - The Mid-range in Penon Quattro is taken care by one 8 mm graphene diaphragm-based Dynamic Driver, where the magic starts. The mids on the IEMs are precisely balanced and one of the highlights of Penon Quattro. The mids are very lush, musical and intoxicating. The notes on the Quattro have the right weight which makes it very fun and immersive while listening to popular pop numbers. Such as ‘One Kiss’ by Dua Lipa and Calvin Harris. Both male and female vocals are very natural and organic in texture. The Penon Quattro surprisingly showcases beautiful and precise timbre when it comes to instruments. We enjoyed listening to ‘Rabb’ (feat Tochi Raina & Jaggi) at Coke Studio India, composed by Amit Trivedi on Penon Quattro. The transient response is above average in comparison to similar-priced IEMs. The upper mids have very precise energy and clarity while the lower mids are thick and warm.

• Highs: - The Highs on the Penon Quattro are balanced and smooth across the frequency. The 6 mm custom Dynamic Driver is tuned beautifully by Penon’s Acoustic Engineers to showcase a cohesive, natural and life-like presentation. There is no hint of shoutiness or nasty peaks and thus very helpful for longer listening sessions. The level of articulation is the most impressive and surprising part of the Quattro, even after having the smooth and forgiving approach. While the lower treble is just average the Quattro despite being warm and musical IEMs showcases a very high-quality upper treble while listening to electronic guitar-based tracks. We also loved the texture of the bass guitar while listening to ‘Late Night Feelings’ by Mark Ronson feat Lykee Li. There is sufficient air across the frequency to balance the highs.

• Soundstage & Imaging: - The Soundstage of Penon Quattro can be best described in one word that is ‘immersive’ The soundstage is above average in width and depth and thus provides sufficient separation in busy rock tracks but here we would like to add that the separation of the instruments could have been better. When it comes to imaging, is one of the other areas where the Penon Quattro excels. The imaging on Penon quattro is quite precise while the layering is just average at best. We enjoyed listening to ‘Zariya’ composed by AR Rahman for Coke Studio India.

• Synergy: - The source matching plays a very important role in the case of Penon Quattro since it is a 4 DD-based IEMs. After testing it for months we at Aural Cafe are very confident to suggest powerful transparent neutral sources such as Dethonray DTR1+, and Aune M1p. The quality of the sources will play a big part in extracting out of those 4 DDs as they love power. Dongles such as Aune Yuki also did a decent job in driving the Penon Quattro but if you want to show the true capability of the Quattro just plug it into a source such as Aune M1p or Dethonray Listening M1 and you will be surprised. When it comes to the tips Penon Quattro pairs well with Spinfit CP145 and neon and grey stock tips. The stock cable does a decent job in extracting micro details from the musical world, but it pairs a bit better with high-quality SPC cable such us Linum SuperBaX, DualBaX and PW Audio Monile two-wire. The soundstage, separation and vocals improve a bit with these SPC cables.

Conclusion: -

Well, Penon Audio did a magnificent job with Penon Serial and when the news of Penon Quattro came in every fan like us of Penon was excited. We can say that the Penon Serial is quite different from the Penon Quattro when it comes to tonality. Penon Serial is like wine that intoxicates you slowly to the galaxy of music. Penon quattro is raw, musical and a bold presentation by the Penon Audio team. If you are into analytical IEMs and more into rock, metal and classical genres of music Penon Quatrro is not for you, For the rest of the genres such as hip-hop, pops etc. Penon Quattro does a wonderful job, just don’t judge it by its cover, by which we mean to give it time and you will understand what Penon Quattro is capable of.

Non-Affiliated Link: -

- https://penonaudio.com/Penon-QUATTRO.html

24-Mar-24




Chain: HiBy R8 à Effect Audio Ares S (8W) 4.4 mm à Penon Quattro à Spinfit W1 ear tips

Introduction: The Quattro and the Ares S 8W cable were loaned to me by my good friend Sandeep Agrawal. The Quattro is a 4DD set with 1 x 6mm custom dynamic driver for High frequency, 1 x 8mm graphene diaphragm for the Medium frequency, and 2 x 10mm composite diaphragm for the Low frequency.

Here are my brief listening impressions of them.

But first, a little about me- I prefer a balanced to warm sound for enjoying my music. I own sets like the 64 Audio Trio, Final A8000, and Thieaudio Monarch MKII. I dislike any one frequency overpowering or dominating all others, be it bass, mids, or the treble. Occasionally, I do also listen to reference/analytical sets with a flat sound signature. I very rarely prefer all-BA setups, no matter how high-end they are. Technicalities and capabilities aside, I always look for an IEM/HP that grabs my attention the moment it starts playing (trust me, IEMs/HPs that really connect with me always grab my attention the moment they start playing). It should sound clear, fun, musical, draw me into the song, and most importantly make me feel the emotions! If a Rs. 1,500/- (USD 18) IEM does this, I buy it too.



Design and Build Quality: This is a very well-made IEM that feels good in-hand. The earpieces look nice with their bright blue faceplates and the Quattro branding on them. No complaints.

Comfort, and fit: I found the Quattro to be medium-heavy with a deep in-ear fit. They are chunky boys and not the lightest. They did feel present in my ear most of the time. While they’re not uncomfortable by any means, they’re definitely not the most comfortable too. As always, YMMV here. The isolation with the W1 ear tips was nice. Nothing mind-blowing and nothing bad too here. It’s good and as expected.

Brief impressions on the sound quality: The first words that come to my mind are warm, musical, detailed, and analog-ish sound. Right from the first song, the music just grabbed my attention and drew me in. While listening to this chain, time and again I was hitting imaginary drums and strumming imaginary guitars in my hands. It was just so much fun! In energetic and pacy songs like Caroline by Patrick Droney, I was expecting the next drum hit and wow’ed when it came. Songs like Daddy Doesn’t Pray Anymore by Chris Stapleton were extremely emotive and had me lost in them with my eyes closed.

The Quattro’s bass is excellent. Thumpy and heavy, but executed very tastefully. Its vocals are excellent, as is its overall tonality. A very natural and musical sound that can be listened to with zero fatigue for hours. It has a full-bodied sound, which is detailed too. And the details are never sibilant. In fact, they’re very rounded and polished! On going through the Penon website, I see one of the reviews there say that the Quattro has a ‘dark treble’. Having heard it, I now know what this reviewer mean.

Overall, I’d say that the Quattro has an analog-ish sound that’s done extremely tastefully. It has a lovely wide soundstage with an airy sound. The layering and separation are nothing short of impressive! For example, the song Popular Monster by Falling in Reverse gets super-busy after the 2-mins mark. I have heard many IEMs stumble or make a jumbled mess of this song, but the Quattro handled it like a grandmaster! Never once did I find it struggling and it presented even this loud and busy song with a lovely musicality to it. My go to song for testing spicy treble is Into The New World by Girls’ Generation. Here the Quattro handled the sharpness very well and presented this song too with a very musical flavor.

Usually, I hear both these songs purely for testing. But I think this is the first time I actually enjoyed listening to both these songs while testing them! That’s saying a lot about the Quattro and this chain.

Quattro with its stock cable: I heard this for a bit but after listening to the Quattro with the Ares S 8W, I’d say that this chain to still has all the elements and qualities mentioned above but to a lesser degree. With the stock cable, the sound became leaner and slightly less musical.

The Ares S 8W is simply way too superior and brings out the Quattro’s best. I highly recommend it to anyone owning/using the Quattro.

Conclusion: As I wrote in the beginning, the Quattro drew me in with its sound and connected me to the emotions in the music. Any IEM that does this and that too to such a high degree, I give it 12/10. Not gold, this IEM and chain deserve a platinum award.

Occasionally something comes along that shifts your perspective, and nothing's quite the same again.

I recently had such an experience I'd like to share with you.



Since demoing Campfire Audio's USD $3375 Trifecta last year I found myself embroiled in controversy, and worse yet of my own making! Let me explain.

Upon first hearing Trifecta at my local dealer they were terrible - nothing but a wall of bass, with no treble to speak of and drivers so slow I wondered if they were faulty. Repeated Trifecta demos with different sources over the following months yielded similar impressions.

Naturally I did what anyone would - sharing my candid Trifecta thoughts online to what I assumed would be measured and constructive feedback.... you can probably guess how that went!



Having since detached the last of the pitchforks from my behind I've deconstructed what made Trifecta so disagreeable; In a world of BA driver dominance the notion of an IEM with three dynamic drivers felt a bit like a P.T. Barnum novelty I wondered if the world really needed.

Fast forward to earlier this year when Penon Audio announced the release of their new Quattro IEMs which boast not three, but four DDs and my eyebrows shot up, as I kept an eye on the forums as ownership impressions trickled in.

Much like Trifecta, Quattros have generated polar reactions - many owners adore them, others complain they're not what they expected. So when Penon offered to send a pair in exchange for a review I agreed, knowing this is one evaluation that'll probably end in triumph.... or disaster.

Packaging​

The USD $399 Penon Quattros arrive in the usual small yellow Penon cardboard box, inside of which is a fairly plush & well-made leather carry case that strikes a nice balance between being small enough to pocket but roomy enough to house the IEMs with a large 8 wire cable.

There’s also a small leather accessories case, inside of which are three sets of silicone eartips in 3 sizes along with a shirt clip & cleaning tool.

The Quattros come bundled with a seriously impressive blue 2pin silver-plated & graphene cable, in your choice of 4.4mm, 3.5mm or 2.5mm terminations.

Ergonomics​

The Quattros' medical-grade resin shells are vented for pressure relief and are on the chunkier side of the spectrum, which is understandable given each earpiece houses 4 dynamic drivers.

Earphone fit is a personal thing. I find the Quattros are solidly comfortable even for long listening sessions, though smaller hybrids IEMs with only a single DD can be better. There's a moderate amount of heft to the Quattros & they stick out a bit, but given there's 4 DDs in there I've no complaints.

I'd prefer resin rather than metal nozzles which tend to grip eartips more firmly, but that's a minor quibble. Ergonomically the stock cable has given me no complaints, being very pliable & draping nicely.

Sound Impressions​

I tested the Quattros with my Hiby R6 Pro II set to hi-gain in AB mode, at a volume level of 28.

The Quattros are bass-driven with a thick, rich midrange & dark treble that strongly emphasises their smooth tonality & dense note weight.

Bass

It would be unfair to label the Quattros basshead IEMs since doing would imply bass dominates their presentation, yet they deliver as much as possible without crossing the threshold - remaining well balanced, but with enough power down low to provide a massively satisfying sense of fullness.

With dual 10mm DDs for the lows, midbass is emphasised over sub and there's enough midbass in particular to infuse the presentation with a huge amount of warmth and body. If you prefer lean sound I strongly recommend looking elsewhere!

There's plenty of thump and rumble for electronic music, and bass texture is reasonably gratifying without being the best I've heard. Bass decay is believably prolonged, without those two DD's being too slow to keep up during fast-paced music.





Midrange

If you want a meaty, full-bodied midrange you can sink your teeth into the Quattros have you covered, and this is where a lot of your attention will be riveted.

What most impresses me about the Quattro midrange isn't the impressively hefty note weight -easily the best I've heard under $1000- nor their remarkable coherence which is absolutely NOT what I expected from an IEM with four DDs (if anything I feared the opposite!) but rather their sublime smoothness.

This is an IEM you can listen to for days without ever hearing jarring peaks. Music just flows in a manner that makes you want to keep listening for hour after hour, and their strongly lower-midrange emphasised tonality is once again unquestionably the most satisfying I've heard under $1000.

Treble

The Quattros are unashamedly dark, and this is where some may have issue with them. Though treble quality is quite good, avoiding the grain we see in entry-level IEMs, Penon have tuned the Quattros conservatively in this area to avoid any nasty peaks or sibilance.

Instruments like cymbals, snares & bells do not feel rolled off but are represented less prominently, and though the Quattros' treble never stands out as deficient, they aren't my first choice for rendering instruments like violins as too much of my attention is focused around the lows & mids.

The upside of the Quattros' safer treble is the total absence of fatigue, inviting longer listening sessions.

Technical Performance​

The Quattros expertly straddle a fine line of clearly prioritising tonality over technical performance, without starving technicalities of capability to the point they become distracting weaknesses - Penon have been tuning IEMs for years and clearly know what they're doing here.

The soundstage is moderately wide & surprisingly deep for an IEM of this price, never feeling artificially stretched nor claustrophobic. I wouldn't call it a strength however, as there's so much warmth with instruments rendered quite large, so the stage can feel more intimate than it really is.

Resolution is quite good for this price, though they definitely aren't detail monsters given their more safely-tuned treble. However vocal nuances come through with satisfying prominence, embellished by their decadently warm tonality & delicious smoothness.

Imaging and separation are solid without calling massive attention to themselves, and most importantly all four DDs are remarkably coherent & fast enough to keep up even with modern EDM music. Dynamics are also very good, an attribute I value strongly.

IEM Comparisons​

I compared the Quattros with EMs at hand, using the Hiby R6 Pro II set to hi-gain in AB mode with the Quattros requiring a volume level of 28.



Simgot EA1000 - 1xDD 1xPR (USD $219)



The EA1000 are much smaller but heavier thanks to their stainless steel shells, yet slightly more comfortable due to the size difference. Requiring 19 volume on the R6P2 they’re easy to drive.

EA1000s are vastly leaner than the Quattros, with a far brighter & more neutral sound. EA1000 bass is very impressive & stands out from the rest of the presentation more than Quattros' does, which you may see as a positive or negative. The EA1000s are more sub bass oriented whereas the Quattros have far more midbass, and greater overall bass quantity.

The EA1000s lack of midbass helps maintain a cooler tonality, along with less lower midrange than the Quattros - a symptom of the EA1000 being tuned closer to the Harman target. I find the Quattros' more full-bodied midrange much more convincing, whereas the EA1000s emphasise the upper midrange more.

The soundstages of both IEMs are similarly wide but Quattros' is deeper. The EA1000s lag slightly behind in resolution & imaging sharpness, and both IEMs feel equally coherent.



ISN Neo5 – 4xBA 1xDD (USD $289)



The Neo5s are physically smaller & lighter than the Quattros, and feel like they’re sculpted to my ears almost perfectly - comfort is close to the best of any universal IEM I’ve tried. Requiring just 19 volume on the R6P2 they’re easy to drive.

The Neo5s are much more v-shaped with a thinner tonality than the Quattros. I find the Neo5's DD slower to respond to fast music, and am surprised to find Neo5s bass quantity slightly lower & bass texture more pillowy than that of the Quattros.

The Neo5 soundstage is narrower & shallower, resolution feels a notch lower and they're less coherent perhaps because their DD can struggle to keep up. The Quattros boast better dynamics & note weight, treble feels smoother & higher quality on the Quattros though the actual amount of treble quantity is higher on the v-shaped Neo5s which come across as more excited but far less smooth & refined.



Penon Turbo - 6xBA (USD $549)



Turbos’ shells are much smaller, yet only slightly more comfortable than the Quattros as the areas that make direct contact with my canals fit more snugly. Needing 23 volume on the R6P2 they're easier to drive.

Turbos' tuning switches I keep in their stock positions, and unsurprisingly the biggest difference lies with bass as the Turbos' BA bass is no match for the Quattros. Turbo have lower bass quantity, bass decay & texture are commendable by BA standards but poor compared with the Quattros' dual DDs.

The Turbos feature a similarly dark tonality but they're far less full-bodied than Quattro, with less impressive note weight & dynamics. Turbos emphasise the upper midrange much more which I don't care for, instead I find the Quattro's meatier midrange far more engaging.

Though the Turbos' soundstage is slightly wider, imaging is marginally sharper & they feel slightly more resolving, to me those improvements don't compensate for their inferior tonality, and though their BA drivers separate instruments during busy passages better that difference is also quite minor.



Fir Audio XE6 – 4xBA 1xEST 1xDD (USD $3899)



The stainless steel XE6s are much heavier, which I notice occasionally during long listening sessions. However they're sculpted to my canals decently and comfort levels are similar to the Quattros. Needing just 17 volume on the R6P2 they're easy to drive.

The XE6s feel like the Quattros taken to the next level with an even bolder, more coloured presentation with far more warmth & midbass that can take time to adjust to. Instruments sound much larger on the XE6s, with an even thicker & denser sound with massive note weight few (if any) other IEMs can match.

XE6s boast superior dynamics, a deeper & wider soundstage, deeper & more impactful bass, higher resolution across the board, and smoother, more prominent & higher quality treble thanks to their EST drivers. The Quattros feel more neutral & less coloured by comparison, and may eclipse the XE6s for sheer musicality but trail in other areas.

More IEM Comparisons​

I was able to compare the Quattros with some additional IEMs at my local audio dealer, Addicted to Audio in Melbourne. The Hiby R6 Pro II was used, with the Quattros set at a volume of 28.



Dunu Kima – 1xDD (USD $109)



Physically the Kimas are tremendously light and small, and comfort levels are exceptionally good. Requiring 30 volume on the R6P2's 3.5mm jack I'm surprised by how much power they need.

Significantly brighter which a much thinner presentation, the Kimas feature much more upper midrange emphasis with far less midbass & lower midrange prominence than the Quattros.

The Kimas sound a little shouty & ethereal with a tonality reminiscent of Harman-tuned IEMs, imaging can be a little vague and note weight is far inferior to that of the Quattros, so overall they feel very outclassed.



Noble Audio Stage 3 – 2xBA 1xDD (USD $600)



The Stage 3s are physically similar to the Quattros albeit slightly smaller. Comfort levels are comparable, but the Stage 3s isolate slightly better. Needing 22 volume on the R6P2 they're fairly easy to drive.

I find the Stage 3s a little shouty with more upper midrange emphasis, vocals can feel somewhat distant with a touch of hollowness compared to the Quattros. The stage 3s also emphasise midbass more than the Quattros, but are similarly dark in the treble.

By contrast the Quattros are much smoother especially in the midrange, with a wider soundstage though the Stage 3s' stage is slightly deeper and they're more dynamic. Resolution feels similar between them, the Stage 3 DD driver feel noticeably slower and I much prefer the Quattros' tonality.



64 Audio U4s – 3xBA 1xDD (USD $1099)



To my surprise the U4s seem physically larger than the Quattros and stick out quite a bit, but are perfectly sculpted to my canals and are slightly more comfortable. Needing 24 volume on the R6P2 3.5mm jack they're easy to drive.

The U4s are much brighter & thinner sounding than the Quattros, nor as bass dominant but I find their bass texture to be more satisfying. They're ]more neutral but not as smooth, with vocals tilted slightly towards the upper midrange with what feels like the occasional treble peak present.

The U4s have a narrower soundstage surprisingly, but their background is blacker and imaging is sharper, though note weight is unsurprisingly diminished compared to the Quattros.



64 Audio Volür – 8xBA 2xDD (USD $2499)



Physically Volur seem identical to the U4s, so though they're quite large comfort is excellent. Again they require only 24 on the R6P2's 3.5mm jack so they're easy to drive.

Volur are extremely well balanced & coherent to the point where nothing immediately jumps out about them - they're great at getting out of the way of the music. They're smoother than the U4s with treble that's much tamer, in fact of all the IEMs I've A/Bed the Quattros against Volur are the closest match.

Vocals on the Volur feel quite forward but their bass texture doesn't impress as much as U4s' does, however they're much thicker & smoother though still lagging behind the Quattros there. Volur are more resolving with sharper imaging though, with impressive effortlessness in the way they present detail, and their soundstage is deeper.



Campfire Audio Trifecta – 3xDD (USD $3375)



The Trifectas' shape is rather unusual. They're heavier than the Quattros and stick out quite a bit, but comfort & isolation levels are similar between the two. Requiring just 23 on the R6P2's 3.5mm jack they're incredibly easy to drive.

There's distinct similarities here, both Trifecta & Quattro are very bass dominant with Trifecta bass being even more prominent, going deeper and possessing greater rumble & more satisfying texture, but is also much slower - Trifectas possess some of the slowest drivers of any flagship IEM I've heard which makes them problematic for faster-paced music.

Trifecta are considerably brighter and I notice potentially troublesome treble peaks, but are much more dynamic with even better note weight. They're also more resolving with a larger soundstage, whereas the Quattros are smoother, warmer & more midrange-centric but less impactful and darker.

Cable Comparisons​

As always I tested the Quattros with a number of different cables to get a feeling for how well they scale.



Simgot LC7 (USD $69)



The LC7 adds a bit more treble emphasis so the Quattros don't feel quite as dark, and I notice the upper midrange coming through a bit more.

Though the soundstage is a little deeper and midrange resolution is slightly higher, I can't notice much improvement to soundstage width, dynamics or bass impact either. Since I prefer the tonality of the stock cable the LC7 feels like a side-grade.



NiceHCK DragonScale (USD $157)



DragonScale expands the stage slightly wider, adds a blacker background & sharper imaging, with vocals in particular being easier to distinguish from instruments around them.

There's a slight treble boost, but midbass & lower midrange are more prominent with the stock cable which I miss. DragonScale is so stiff below the Y-split that I'd rather stick with the stock cable for its' superior ergonomics.



Penon ASOS (USD $169)



The ASOS expands the stage in all directions and makes the overall presentation feel like it has a lot more room to breathe. Midrange resolution is higher, and it's much easier to distinguish individual instruments from one another. Treble is also slightly brighter.

ASOS is a very good pairing, though I prefer the tonality of the stock cable despite its' more intimate soundstage - musicality feels higher and I tend to toe-tap more.



Effect Audio Code 23 (USD $599)



In this very impressive pairing Code23 makes instruments sound larger, the stage expands in all directions, resolution increases, and treble is brightened but not as much as ASOS does.

Sonically Code23 feels like a direct upgrade from the stock cable since tonality is similar but technicalities are boosted significantly, though Code23's horrid ergonomics need to be suffered to enjoy them.



Liquid Links Venom (USD $1089)



Venom increases resolution across all frequencies far more than other cables in a way that's very noticeable, delivers a blacker background with sharper imaging & brightens treble significantly.

The stage is deeper but surprisingly no wider than the stock cable. I prefer the Code23 pairing simply because Venom imparts a metallic tonality on vocals in particular which robs the Quattros too much of what makes them special. A great lesson here that cable synergy with your IEM always trumps price.

Conclusion​

Let me put it simply. For $399 if you want sound that's smooth, rich & warm it doesn't get better than this.

Even if you're used to spending ten times that much on earphones, if I just described the kind of sound you love then I strongly suggest demoing the Quattros.

When you've been an audiophile forever you learn each type of sound has it's place. I can just as easily enjoy basshead IEMs as I can a reference-tuned set, but sound that's deliciously smooth without instruments sounding excessively smoothed over.... that's perfect for new music discovery.

The Penon Quattros make me want to listen to album after album which is precisely what I've been doing since they arrived.

I can't recommend them universally because they won't please everyone - some folks prefer a thinner, leaner sound with loads of treble which is exactly what the Quattros aren't. Instead they're warm & bassy with impeccably full-bodied timbre many of us find intoxicating.

I finally get it - nothing replicates lifelike tonality like dynamic drivers, which is why the Quattros exist. They're a brilliantly tuned set of IEMs, an absolute pleasure if you enjoy this kind of sound.

TONALITY: 8.2/10
TECHNICALITIES: 8/10
TIMBRE: 8.5/10
IMAGING: 7.5/10
SOUNDSTAGE: 8.2/10
MUSICALITY (subjective): 8.5/10
CONSTRUCTION: 8.5/10
ACCESSORIES: 9/10
SOUND VALUE: 8/10

INTRO

Penon doesn't need lengthy introduction, it’s among the first hifi chinese audio product distributor and it produces IEMs for years too, under Penon and ISN brands.

This isn’t an amateur DIY IEM maker like NiceHCK or **** and other Ali express OEM companies, it’s a passionate and experienced IEM and cable maker with incredible contacts and manufacturing possibilities. It seems Penon always aims for ‘’musicality meet technicalities’’ audio experience and one of the most special IEM’s I,ve tested from them is the Serial, which is a 3 dynamic driver marvel that you can check my review to know more about.

Yet, this explains how excited and curious I am to review the Quattro today.

Price 400$, the Quattro is a 4 dynamic drivers IEM that use 2x10mm composite DD in opposed sided configuration to enhance their dynamic response, 1x8mm graphene DD for mids and 1x6mm custom DD for highs.

Yes the Quattro is an exotic beast that use similar double dynamic drivers tech to something like Moondrop Bellsing 3



But in this case, it’s all dynamic drivers goodness. But will it be as competitive as the Serial in term value, will it be too similar in tonality or worth collecting for a Serial owner?

I’ll try to answer this question in my review.




CONSTRUCTION&ACCESSORIES



The Quattro has very good construction that is quite similar to their Serial, as small but chunkier.It’s made of good quality resin medical grade plastic that is smooth and not easy to scratch.The back plate has a beautiful wooden pattern, painted in blue. It gives it an elegant and sober look, like I love because I don’t try to dress up with my IEMs.At the back side there is a venting port, it has a filter to avoid dust entering the shell.On top, there is the 2 pin female connector, it’s not recessed and I find connectivity slippy a bit so we need to be cautious to align the male 2pin to avoid bentin it by accident.All in all, with its solid thick resin plastic, this IEM promises good durability, its nozzle isn’t very big so no issue for canal hole size since these are very comfortable and light to wear.



Now in terms of cable quality of construction, as always we are spoiled with Penon and this time it’s a next level since the cable is way better than the one included with Serial (which wasn’t bad in first place!).
Everytime i share pics of this cable, people wanna know where to buy it, how much is it….yet I don’t even think Penon sell it yet so I have no idea, it just mean it’s a looker and this is due to ‘’electric blue’’ color of cable coating.
Not only is it eye- catching but it’s half transparent too so we can see wires inside, yes ... .I pass too much time admiring this cable but it’s that dope looking.
Unfortunately, I don’t have a lot of info about this cable and can only speculate. I mean, I read it using Graphene. That’s it. It's a 4 thick strands cable. You can choose it in 2.5, 3.5 or 4.4mm plug. There is no ear hook and it’s a plus for me (big ears). It feels sturdy enough to pull a car. The cable splitter slider holds well and is useful. The Build is pristine and if it was Effect Audio that sold this cable you can expect 300$ and up. I can’t wait for Penon to sell this cable, I feel it will be a success.
Simply put, I've tried my fav cable Simgot LC7 with it and it was a downgrade, spatiality was less open and holographic, more flat. You don’t need an urgent upgrade cable with the Quattro.



And again, Penon spoils its consumers with an incredible amount of accessories goodies, all fitted in small eco-friendly boxes.
We have the great Penon case that has plenty of space in a compact way, so you can fit 2-3cables and plenty of IEMs and accessories.
Then nothing less than 9 pairs of silicone ear tips, including a wide bore that I feel is the best for those IEM, so it’s no random ear tips here.
You have a leather pouch for ear tips or cable.
A cleaning tool and cable clamp.

All in all, very satisfying construction and accessories quality.


SOUND IMPRESSIONS



The Quattro are warm and bassy, the bass is so juicy you want to be kissed by it and for the mids it can be the same when bass don’t steal the show, non muddy way.

We can say tonal balance is U shape in a thick and lush way, since the bass dominates when asked for, mids are lean but superbly layered and sweet, and treble has just minimal spice to offer some brilliance and snap to percussions mostly.
Yes, we are guilty of pleasure if we consider colored musicality a vice.
And this is where it can go complicated: what is natural timbre exactly?
For some, it needs to be textured and underlined in presence definition, it’s in fact mixed with resolution...an aspect I put in technical performance that has nothing to do with final musical enjoyment. Unless for plain monitoring purposes!
For me a natural timbre should sound full in harmony and pleasant to the ears, not forced. When I'm in real life, it's very rare I find a vocal sibilant or shouty...this is what I ask from an IEM too: to let the soundwave flow in harmony, or at least without a peak that puts sound info that shouldn’t be there.

And this is what we get with Quattro but with a different macro dynamic rendering where energy comes from bass, lower mids and mid treble mostly.

Even if it uses 4 dynamic drivers, it’s not tuned to sound technical or analytical at all. Its near dark treble wise, everything is so smoothed, their no edge to definition yet the instrument are fully restitute, mids feel lean, yet they are intimate and not recessed in a way you feel their presence is lacking, treble is gentle but can pick up sound layers effortlessly as well as intricate details of acoustic guitar in a lean way…

The Quattro is a niche yet intensely immersive sounding IEM with the right music. Even more so than the Dome, which makes Serial feel utterly versatile even more. We can say it’s a guilty pleasure too and would impress the bass lover as well as warm sound signature lover, treble sensitive people will find the fun laid back musicality very welcome too.



The bass is what captivates the attention of the listener unless there is none in the music you listen to, then the musical experience will be very different. More the bass is dynamic in your music, the more the Quattro can approach basshead territory due to its fast pounding slam with thick deep and mesmerizing rumble and extension. The dual faced DD used for bass deliver a unique bass experience that is very dense and vibrant and can extend its sustain in a vibrant, tactile and fully extracted way.
Bass line aren’t thin at all, they have full colorful tone but not the most textured attack lead, yet they are very well layered and you can feel you have a subwoofer in your head listening to trap rap or electronic like Kaytranada since the synth bass line are very juicy, tactile and meaty in presence, the elasticity of infra bass in mind blowing.
This means it can deliver proper grunt to electric bass too as well as cello.
Cello sounds lush and more distinctive than the violin which can sometimes sound like...cello.
Double bass is a bit warm, but the deep dense extension will complement well relaxed jazz, less so energetic music style like metal, fast rock because the kick drum definition is a bit darken by sub bass warm and bass line will dominate and warm it presence, what is impressive is how the dynamic of both can cohabit in tandem but not in a sharply define way since bass embrace lower mids and thicken the macro dynamic.
It’s not a clean nor a lean bass rendering and it mean it’s not the most versatile too. I find it excels with Soul, trip-hop, rap, R&B, pop and jazz trio or quartet, not with fast busy tracks.

The mids are lush and lean with a dense natural timbre. It offers full tone with extra low harmonic coloring that can go a bit euphonic when big bass occurs or very smooth and organic with instrumental music or simple singer track. It will feel leaner and more recessed with bass heavy music but the multi DD permit a good layering that doesn't lose the main instrument or vocal of the mix even if it will make the fine micro details of background more foggy.
The vocal presence is wide, breathy and very smooth, the pinna gain is very low so people sensitive to upper mids will never get fatigue from vocal, saxophone or violin upper pitch.
The mids are very centered in the stage while bass and highs add an holographic openness to stereo presentation. I can’t rave enough about the timbre which is very rich and has a natural texture which is more evident with pristine recordings like the ECM label.
Both male and female vocal have a life like presentation which is intimate and enveloping, while I say the dynamic can feel lean it's more about V shaped mix, with neutral mix like last Elina Duni album, the vocalist don’t seem too far and both tone and timbre is top notch, their no lipsy boost, no sibilance, no warmth veil because their no big slam in the music that affect overall resolution.
With trap rap music from IAMDDB, it’s less clean sounding but the lean vocal is well layered above the big bass rumble and slam, this is very enjoyable but some people might need brighter vocals to appreciate the lyric articulation.
Both the bass and mid range are so exotic that it’s hard to describe the very appealing flavor it deliver, one thing sure, these are very colored with warmth so if you like your mids crisp or bright or very energetic this will not be for you, even as a warm mids lover I find the mids lacking a bit of energy and clarity.


When it comes to treble, don’t expect a vividly bright presentation because it’s laid back here with just an extra upper treble boost to add snap and bite to percussion and guitar. It’s not plain dry or too polished on top, we do have slight brilliance to percussions which are easy to pinpoint but not dominating the mix like analytical IEM can offer.
As well, those percussions are magnified in sharpness, which add brilliant snap that favor upper range metallic percussions more than snare, some percussions can feel not fully represented.
Lower treble is very soft, it doesn't boost texture presence a lot which means violin sound a bit buttery and not very edgy in attack, this can be detrimental to fast playing of Presto sonata from Bach for example which will feel a bit glued in attack timing. Yet, for relaxed chamber classical, this lush inoffensive musicality will be beneficial. For a big symphony, the treble will be too dark and make the readability of a full orchestra impossible.
Acoustic guitar are thicken with low harmonic, they don’t sound thin or overly metallic, nor crisp or clean, it have a foggy density to its body and the minimal sparkle release aren’t enough to make it sound airy unless it’s single upper pitch note which will have this natural brilliance delivered.
It will be evident the Quattro treble can produce brilliance with higher pitch now, this benefits classical guitar more than harmony stroke.
Electric guitar sounds full and the timbre can be very realistic since unlike acoustic guitar the sound info in its density is important, sure distortion grain is a bit softer but it finds a good balance between presence and dynamism, alas the rest of tonality don’t benefit rock or metal music.
All in all, the highs don’t really attract attention and like all the rest of the spectrum it’s colored to fit a liquid tonal cohesion, while this permits to crash cymbals sound smooth, it affects proper clarity of note release. Treble heads will not like this kind of laid back highs, while treble sensitive and dark highs lover will find it quite cozy.

The Soundstage is quite impressive in wideness and tallness, but not only since the presentation is very holographic, it surrounds you from left and right and front which is a bit static but not far from you. Listener can get lost in an immersive musical experience where he is in the middle of the soundscape.

Imaging isn’t plain bad since the layering is in fact very good, even bass have its layer where vocal and mids instruments sit on, we can track some percussion or instrument but not all of them so at the end the tuning is too dark for any serious monitoring. Definition edge is too polished for sharp separation too.


SIDE NOTES

Firstly, at 100db of sensitivity benefit from amping power, but since impedance is a bit low at 16 ohm some dongle or DAP will add harmonic distortion and bass gain euphony, this happen with Xduoo Link2 Bal and Penon Tail for ex, so this make the Quattro ultra warm and boomy. With powerful sources that have low output impedance like Xduoo X20, Ibasso DX90 or Tempotec V6, the pairing is better resolved and more balanced even if still bassey this bass layering is cleaner and better defined, less blurred in presence edge.

Cable wise, stock one is excellent but not modular, so I guess you will swap cable even if it doesn’t greatly affect sound performance unlike with multi-BA or Hybrid IEMs or those with very high sensitivity.

Eartips wise, it does inflict a lot on how open will be soundstage and how articulate will be sound layering. Stock green wide bore is my favorite one so I don’t feel an urgent need to upgrade it. Yet I’ve tried blue Fan2 wide bore eartips as well as short wide bore, these tend to widen and deepen even more the spatiality but make mids even leaner and bass less thumpy, more diffuse in sound pressure.

At the end, the Quattro seems to pair better with energetic and crisp sources that have lively but not too exciting dynamic gain. If their slight gain in mid bass it will make the bass rounder punchier which benefit the tonal balance, slight upper mids boost can improve readability of mid range while fully extended and slightly elevated upper treble will show the Quattro can produce brilliance and sparkle and have this metallic snap to percussions.




COMPARISONS



VS Unique Melody 3DT (3DD-400$)

The 3DT are brighter and less bassy.
The bass is more texture in presence and better defined in separation, it bleeds less into mids and kick drum is more punchy. Bass lines are leaner and thinner, sub bass is more rolled off, there is no proper rumble or infra bass density. Quattro feels basshead after listening to the lean bass of 3DT.
Mids are way brighter and seem all concentrated in upper mids, the presence is thinner but more texture, female vocals are more shouty and prompt to sibilance, spatiality is deeper and we have more sound info and micro details. Quattro mids are lusher, thicker, warmer and strangely feel less recessed even if leaner, presence is wider and less compressed too.
Treble is way brighter and crunchier with 3DT, it’s not as sparkly since their zero brilliance in percussion even if the restitution is fuller and more boosted in resolution. We have more micro details with the 3DT but less snap sharpness, snare are more aggressive and percussion more grainy too with 3DT.
Soundstage is notably wider and taller and more holographic with Quattro, it's more intimate and deeper with 3DT.
Imaging is superior and near monitor level with 3DT, definition of each instrument being edgier, it’s easier to track them even if the space is more closed and stock in your head.

All in all, these are polar opposite. For treble head I'll suggest 3DT, while for colored bass, mids lover and treble sensitive I would suggest Quattro. Personally, I find the Quattro more musical and fun as well as more natural and pleasant timbre wise.

VS PENON SERIAL (3DD-300$)

The Serial is slightly brighter and more U shaped, with a more open and transparent musicality.
Quattro feels warmer, darker and more V shape with a crisper but more liquid treble.
The bass is more textured and thinner as well as less punchy with Serial, bass lines are better resolved and more focused, less glued with warmth to kick and mid bass. Quattro slam is more concentrated in energy and juicier, it's more physical than technical, rumble is more boosted, vibrant, but less clean and lean than Serial that have more attack bite too for electric or double bass. Quattro thickens more lower mids too which affect separation clarity.

Mids are more open and crisp with Serial, more transparent, less dark. Presence is more boosted, female vocals are louder but less lush and meaty, male vocals are more recessed and lack of lower mids is more problematic. Quattro mids are warmer and leaner, vocals are better layered as a whole and notably smoother and more natural, we have more note weight but less clean release after attack.

Treble has more bite with Serial, it’s more generous in texture and micro details, it sounds more open and airy yet less delicately brilliant. Percussions sound fuller while Quattro extract the brilliant edge of them. Ultimately the highs or Quattro are darker and more polished in texture and presence.

Soundstage is wider and deeper with Serial, less tall and holographic, more flat and in front of the listener while you put in a multi layered soundscape with Quattro.

Imaging is way better with the Serial, even for bassline and kick drum positioning, it's superior to 3DT too.

All in all, I can’t lie to myself and consider both tonal balance and technical performance more refined and superior with the Serial. I do prefer the lusher vocal timbre of Quattro as well as this much needed mid bass slam but it comes with too much trade off in terms of resolution.

CONCLUSION



Subjectively, I tremendously enjoy the warm sparkly bassy U shape tonality and dynamic of the Quattro, which is very different in musicality than the older, brighter and more balanced sounding Serial.

Objectively, I can see this IEM as being hit or miss depending of music genre you listen too, for anything fast rock or jazz, it will be too dark and lack proper definition of instrument presence, for some, the pina gain and mids dynamic will be too lean as well, for other, Quattro will be to basshead.

There's no doubt I was a bit destabilized by the bassy and dark tuning choice, but the more I listen to it, the more it grows on me…but was it burned in too that helped open up to spatiality and make it more immersive and addictive? I can’t see but will suggest at least 50H before making any conclusion.

Fact is: we are in guilty pleasure territory, near basshead level of bass joy which is nothing like i’ve heard before, for this experience of round rumbly pouding luscious bass performance, I do think the Quattro is worth an applause. Then, the smooth natural timbre might restrain the dynamic push of mid range, which is perfect for slow music like pop, soul and R&B.

The Quattro is an exotic audio experience that will be rewarding for bass lovers as well as those seeking fatigue free treble that is buttery smooth yet has this special crispness edge that makes percussion edge and acoustic guitar sparkly and snappy, within a thick macro dynamic.

Simply put, the Quattro isn’t technical but musical sounding, and I respect the singularity of musical experience, which in that regard is certainly addictive.

This is Recommended IEM for those that don’t seek bright, neutral or uncolored tonality, as well as for Serial owners seeking a sound signature sidegrade with an upgrade mostly made in bass energy, dynamic, density and fun.

----------------------------------------







PS: I want to thanks Penon for sending me this review sample. I think it's evident that this audio distributor is honest and accept diversify independant reviewer like me, as well, their no affiliated program to feed any self interested $ benefit. My passion is IEM, and it's what feed my ears (and explain 200 IEMs collection)

You can order the Penon Quattro for 399$ here: https://penonaudio.com/Penon-QUATTRO.html

Penon Quattro Review
Redcarmoose Labs January 28th, 2024



Penon
If you don’t know who Penon is they are the neighborhood audio retailer who specializes in personal audio gear. They got their start retailers of other makers gear first, and made cables. Then they started to make IEMs, and Dongles etc, etc. Really they are probably most known now for their IEMs and cables, as well as superior service from their retail site.

Every year Penon gets bigger and bigger, yet they seem to never forget where they came from, always being humble and never pulling-off the shenanigans other retailers do. No long pre orders which are canceled, no confusion about what you are actually buying. They offer a great warranty on their IEMs and offer the best customer support in the business. Of course hopefully you will never need customer support after a purchase, but if you ever do they will back you up, and not let you down. Always remembering their roots and beginnings as the common working man, and it shows.

This review is too long and I’m too lazy to list everything Penon (or their sister company) ISN makes. But since May of 2022 I have reviewed 63 Penon Store retail products, and many (of them) full-fledged Penon/ISN creations. If you're still curious about all they make, just look at my list of reviews, as I have reviewed almost everything they make.

With the above stated I have never come upon an IEM exactly like the Quattro.

The Penon Quattro:
Such an IEM goes to further promote the Penon House sound. A House Sound is like a rock band's sound. Yep, you go ahead and purchase the albums/CDs and you can hear a similarity to past purchases. Only once in a while they experiment with new styles of replay to almost reinvent who the band is. As such you hear a little of the old band’s sound mixed with whatever new experiment the have come-up with to keep things fresh and innovative. Is the Quattro IEM like that, a variation of the Penon sound?

Yes and no!
What I’m trying to say is that the good old Penon House Sound is inside the Quattro, but I have never come upon an IEM that was so sensitive to amplification and cables. Yep, at first after burn-in I thought really only amplification was important? Yet as always it is synergy as to how you find the tone from everything in the signal chain. Now most of us reading this review already know how this signal chain set-up works, and what to expect. But no………..not here you don’t. There is a character of the Quattro that can be altered to either find romance or be left out in the cold.

I wish I could review the Penon Quattro to be completely well rounded, and if set up right it is, being it plays all genres as such. But getting there to where the Quattro sounds vibrant can be a little of a challenge.



Design and build ideas:
I can guess the Serial the 3 DD driver IEM was the inspiration for the Quattro? Penon makes only two pure multi DD IEMs. At just $299.00 the Serial could be considered Penon’s greatest achievement.

The 3 driver Serial’s greatest accomplishment is correct timbre. IMO

6mm pu diaphragm for high frequency
8mm titanium-plated for middle frequency
10mm biological diaphragm for low frequency

So imagine with me just how different the Serial is from most IEMs. Most IEMs use either a Hybrid configuration to use a DD for bass and balanced armatures for the rest. Then there are Hybrids that also go and mix a number of methodologies to arrive at an overall tone, showing the midrange and treble to offer separation from a differently chosen driver set-up. In the case of Penon we are using smaller dynamic diaphragms X2 to generate a higher pitched sound, in addition to the bass diaphragms. Then of course there are Planar IEMs and single full-range dynamic driver IEMs. But the reason to use multi-dynamics is to create a separation of sound constituents apart from the single full-range DD sound........to create a more wide-open stage. To accentuate a bigger and more technically advanced over-all sound by allowing multiple DDs to do the same work as maybe BAs. Yep to have a midrange DD instead of a BA, and another treble DD instead of a BA. All this is attempting to overcome the slight BA timbre that is often put in place by BA tuning or BA driver construction, but never ever fully eliminated. Though here it is, yep gone is the Planar timbre, gone is any BA timbre because no BAs have been utilized.

Quattro:
Driver：4 Dynamic driver
1 x 6mm custom dynamic driver for High frequency
1 x 8mm graphene diaphragm for Medium frequency
2 x 10mm composite diaphragm for Low frequency

So now the addition is totally new driver make-ups and a dual 10mm composite DD for bass. The difference from regular DDs is the placement being horizontally opposed. While like the Serial we still have a passive 3 way crossover and 3 sound tubes. The Serial and Quattro both have similar build values and even though they are still constructed close to the same, there are very different outcomes.



Amplifiers:
The Sony TA-ZH1ES and Sony WM1Z DAP:
My joy was finding a place to call home. Some of the very the best IEM replay I have ever heard in my life regardless of cost. Why…………timbre and imaging.

Timbre: Audio replay is very dependent on driver character to relay the sounds in the recording. We are never fully guaranteed to have correct timbre even in the recording, but the documentation of correct timbre is often in the recording only to be skewed by the IEM into a form of unnatural playback. Here we are almost guaranteed correct timbre through the use of advanced DD design.

Imaging: This is also a critical subject inside the Quattro review. Why? Because every amplifier I used produced different styles of imaging, even every cable I tried produced different styles of imaging. Now there is a place where timbre and imaging come together. This is simply how we hear instruments or vocals separated inside the stage. This imaging is often mainly from transients. So imagine for a moment this imaging which can (especially with vocals) find itself both tone wise being too far back in the mix due to placement inside the stage, and physically put inside the correct playback position due to imaging. Yes, they are related, even though as reviewers we often try to separate the concepts.

That said the Penon Totem cable positioned the Quattro vocals and upper-end separation into an elaborate spacial clued carnival into which everything was totally big and full-size into the stage with the desktop Sony TA-ZH1ES. Now here is the mind-bender………….

If the Quattro needed midrange or treble tone brightness to wake-up the Sony TA-ZH1ES would not be my first choice. In fact it is the darkest amplifier I own. Darker than the Sony WM1A, darker than the Sony WM1Z, darker than the Penon Tail Dongle etc….etc.

So what do we learn from this?
The TA-ZH1ES has the best dampening factor, because it's a desktop and fairly powerful. Now the confusing thing is that there is also better spacial realization from combining the Totem Flagship cable with the TA-ZH1ES and Quattro. Normally something like the Totem Cable goes better with BAs, yet once more we are going to a place of surreal results? Now this is not to say that you have to use the Quattro with a desktop, no in fact I used the Penon Tail Dongle to get great results, it is just that they were not quite as good as with the TA-ZH1ES or the WM1Z Sony DAP. What this all means is you just have to play around with gear. And don’t go by any preconceived notions as to what the results will be. Meaning never have I had the Penon Solar be so very different from the Totem cable? Where the midrange with the Totem Cable and Quattro was bright and separated, the Solar was noticeably warmer right at the vocal placement with the TA-ZH1ES amp. Again all this means is you need to play around with cables to reach a level of replay. You will need to rotate in different amplifiers to find a level of replay and finally you will need to try different combinations of amplifiers and cables to reach synergy here.

These results in consequence mean there are many levels of satisfaction which will take place. And this satisfaction is not readily noticed to be always correct. Meaning it takes an hour of listening to know if you're out of the woods yet. It takes playing through multiple genres to know if you are out of the dark.


Left to right:
The Sony WM1A, the HiBy R3 II, the Shanling UA3 and the SIMGOT AUDIO DEW4X

The Dark:
This is simply a term where in listening there can be a number of realizations which go to spoil the party. It could be that the wrong combination of Amp/Cable/Ear-tips or volume level gets a smoothness which starts to become boring due to lack of separation or lack of timbre realization inside the stage. This is not exactly the Quattro’s fault, it is just delineating the fact that there are two sides to the Quattro. And I will repeat it is not just power, though power did do much of the change. So it is the power quality of amperage and the tone. Mixed with the style of ear-tips you use and the cable tone. Plus there are multiple levels of success. Meaning I didn’t realize for multiple days just how good the Quattro was. There was the 200 hours of burn-in and finally discovering the TA-ZH1ES desktop, then finally folding in the Totem cable which really showed me the light. While at other times multiple combinations were adequate, sometimes more adequate, sometimes less, and the worst………………

The Sony WM1A:
Yep, this was how I first got a clue that it wasn’t amplifier tone which was the issue. Because the WM1A has the brightest midrange and widest stage of anything I own. Trying the WM1A with the Quattro out of the box showed very much this flat-field phenomena of soundstage. Yet also after burn-in with the Sony WM1A 200 hours did nothing much but add smoothness. And strangely the enhanced physicality of the Sony WM1Z DAP was the cat’s meow! So it was the mid centric stance of the WM1A and not just the lack of power that made the Quattro lackadaisical. What I can surmise is it is a combination of many things, including the listeners hearing and physical attributes of their ear-canal.

The Shanling UA3 Dongle
The Simgot DEW4X Dongle
The HiBy R3II DAP
The Penon Dongle


The Penon Tail Dongle above

With trying the different Dongles it has to be said that often they provided way more power than the Sony DAPs yet the confusing thing was the Sony WM1Z has the same power output as the 1A, yet the more robust playback was in-fact what the Quattro craved. Get it more stark contrasts in playback and you will be greeted with a style of reality. I mean somehow the HiBy with its M signature was less involvement than the DEW4, Penon Tail or Shanling UA3. Now my next adventure was trying different cables to use with the Quattro and the different Dongles. Yet those results were of even smaller consequence so no need to list them, except to say these differences at times seem small but it is just that, small changes in which there can be found greater separation and vocal tone being projected out to form a better and more involving playback experience. Most of this had to do with long listening sessions where at first all seemed well, but after a half hour there were elements of boredom arriving, even taking a drink or two didn’t seem to add any emotional involvement or boost the perception of clarity or dynamics. It was truly finding the right source and staying with that source that added success in the end.

The Sony WM1Z, one of the very best sources used today.

Cable changes:
All results with the Sony TA desktop amplifier.

Penon Totem: $699.00
Here was the best of the best. Fully itemized and flowing inside of the stage of a 3D generation. The contrasts sonically as well as positionally were a total thrill. Such instrumentation and vocal separation were some of the very best timbres and decay I have ever heard in my life…….truly what the Quattro was about. I could go on, but just realize this would have to be heard to be totally understood. There are parts of this playback that can’t be put into words. Simply totally natural and getting emotional involvement due to the stage and fireworks inside that stage. The reverberations and tonality were the stuff of dreams. The stage was not only wide, but big front to back and top to bottom, way bigger than I have ever heard the Quattro become. Heaven! There was a spicy timbre to the cymbals which were found generated way farther out as well as an aquarium effect to the whole playback, that made me never want anything else………….ever in my life.

Penon ASOS: $169.00
While noticeable in doing what its character is. Meaning there is a reality to the Quattro that somehow lets cable characters totally come though? Now while not as great on the forward stage and outer stage as the Totem, we still have a personality that totally works here. Probably the transparency of the ASOS, as there was a fluid and open soundstage as well as a defined bass area apart from the involved midrange. The ASOS was exactly as I describe it in my review, maybe more so, if that makes any sense? Lol

It's maybe the added nice stage girth and authority that is so special with the ASOS?

ISN GC4: $179.00
Well another cable that somehow ultimately becomes itself here. A giant lower stage with increased girth of drum elements, plus a gold reinforcement of physicality and density to things. While there was a slight repositioning of elements inside the stage as not as wide-open as the ASOS, it was the thicker and closer to home physicality which still made this totally work. I still can’t get over the below the belt action here. The size of playback and girth of performance? The sheer manliness of the ISN GC4?

All joking aside, there was a finite personality to the GC4 in that it was 100% itself with stage positioning and the cable proved it’s worth, when this was one cable that sounds way bigger than it’s size would have you guess, also strangely it wasn’t dark at all? I mean there were elements of a dark character except also a detailed edge that just let you know where your money went.

ISN CS02: $69.90
This was the only cable that didn’t work today, fortifying the fact that I’m not totally crazy, just slightly deranged. Where once again the Penon Quattro full-filled its role-in-life to show us the reality at hand. A smoother take on constituents of playback sending the Quattro off onto the area of too smooth. Yet below that playback……meaning below the midrange was the tell-tail wide-stage the CS02 was known for……..just another example of just how transparent the Quattro is. Just not enough silver energy work to make this combo enjoyable for an afternoon. Now I don’t want to ruin the party here. As if the only other high performance cable you had was the ISN CS02 and you were dead-set on the Quattro, maybe a brighter amplifier would work? Still if you had the CS02 in your stable, there is a chance you have more cables, as the included cable does much better at play here.

The Penon Mix: $149.00
Here there is a lot of bang-for-the-buck. I mean really in a lot of ways the Quattro is getting what it is asking for here. Probably primarily for the pure silver attribute which is kicking the midrange and treble into gear? Yep, brighter than many cables and holding a mid-range spatial energy that just makes this combo work. The contrasts, the fact that it is a pure copper cable and pure silver cable which in turn generated a vivid tone displacement into which we get the full range of elements, one of the best at a lower cost than some cables listed here.

The Quattro included Graphene cable: Free!
Really with this amp set-up you could only imagine that this may be the level they use at the factory to choose this cable. Once again Penon have proven that they know what they are doing. Graphene! (More on the Graphene introduced cable build later in the review) Call me a fanboy, maybe I am? Except demoing this specific cable showed that Penon are trying for the best they can include with the Quattro including a cable that doesn’t have the firework energy of the more expensive cables tested today, but at the same time does nothing wrong letting the Quattro become totally itself, just not as bright in places as the other cables, nor as deep and clear as some example of playback today. Meaning we get a fully functioning and exquisite ergonomic example of Penon just doing what they do……….they make cables and about 99.99% of the time find that happy medium to where they included a cable value with their new IEM. With just how sensitive the Quattro is, if there was any complaints about the included cable, they would stand out like a sore thumb if they were there, but all is well. The chances are though you could enhance the sound of the Quattro in a few directions if you were game to experiment with additional aftermarket cables. In fact, if you were wondering which cable I used to find out how the the different amplifiers worked with the Quattro this past ten days, it has always been the included cable, as I felt at the end-of-the-day the included cable showed itself to offer a standard baseline of both performance and middle-of-the-road tonal response.

ISN Solar: $399.00
Laughably the Solar was not sounding as it normally should. I mean this if anything shows how the Quattro can be left-field all of a sudden. There is nothing wrong with this cable, in fact it is one of my very favorites with so many IEMs, and it is not about being warm, except being called the Solar by Penon it probably has that feature. Despite the warmth the Solar was/is great with the ISN $449.00 EST50 IEM. I mean to use the EST50 as an example, I will compare the two in the IEM comparison section of this very review. Yet I am beside myself as to why the Solar is not near what the Totem cable was today? Something about how maybe with this darker amplifier and Solar it pushed the vocals to a too smooth of a place with the Quattro? Whatever it was, it was a no-go. Of course if you had a bright amplifier it may work?


Top left to right Penon Volt and Penon Serial
Bottom left to right the Penon Quattro and ISN EST50

IEM comparisons:
Here we will take the past TOTL Volt, the Serial and the EST50 and try and make sense of the relationship between the Quattro and it’s brothers.

The Penon Volt: $799.00
This is a really good comparison as the Volt is one of my all time favorites. Providing world-class midrange and textures for the taking. In every one of my tests today I’m using the Sony WM1A DAP (in the cradle) via the AudioQuest Carbon USB as a file feeder to the Sony TA amplifier to the Totem cable to all (except for one) of the IEMs examined. First off right away you find the Quattro to be way less efficient than the Volt. Yet nowhere in my days of trying these IEM things have I noted an IEM which went to show how the Volt really does have a little BA timbre. Where the issue still is the Quattro doing simpler music simply better. Yep, where the Volt is more well rounded in having faster transients, the Quattro falls into that zone of where slower music is romantic, fully more transporting than the Volt, but get the Volt busy music and watch as it takes it apart. Where with the Quattro we are witnessing simply more real timbre but due to the speed of the drivers ability to transcend transients…………we are held back at times. So the Quattro is slower moving and lumbering under its own weight at times. Yet at that same time is also a world of better technicalities, just sonic switch-ups are not one of them. So pick your music and prepare to be swept away by the sonic abilities of the Quattro, but be assured it’s not everything. And not everything to every song out there. Where here we will make compromises as to whether you want perfect timbre or a style of better pace displayed. As when that pace was displayed by the faster Volt, the timbre wasn’t spot on. Also remember at less than 2X the price of the Volt, the Quattro is not showing as elaborate or as technically superior soundstage, where the Volt with the EST drivers and BAs is going ahead to generate some added space-air.

The Penon Serial: $299.00
The Serial is not as drastic in presentation, meaning not so much highs and lows, and the overall representation of this effect is less vibrancy, less life. Contrary to my planned testing methods I needed to change cables here, as the Totem was not in any way right for the Serial. Going through the Mix Cable then landing on the known stand-by for the Serial…..the Penon Space. There is a pureness here and validation of why when you Google search Penon Audio the Serial all-of-a-sudden comes up in your browser. I hate to say it but the Penon Serial has more pace action than the Quattro. Except everything else is lesser, lesser stage, lesser volume to the notes, even a slightly off timbre that normally you would never notice, but the Quattro makes it heard by comparison. Still the stage here is different, while not as grandiose in stature there are small extra placements of imaging that the Penon Serial does so very well. The Serial becomes the slightly less accomplished smaller older-little brother to the Quattro, with the Quattro showing a more rigid character in playback requirements. Still if you cater to what the Quattro is asking for, then you will gain returns.

The ISN EST50: $449.00
Back to the Totem cable, while the stage is more coming from different areas and different devices showcasing an extra agility in faster music, except showing a slight metallic timbre depending on cable and tunes chosen. So there are ways to make the ISN EST50 sound more mature and close to perfect for me. Yet never will the EST50 go ahead to offer theses big walls of sound, never even though it’s more money there are areas in playback were the EST50 is simply lesser in stage size, that and the vivid extras that come with more information closer to you, that is what the Quattro does, it serves up a big platter of sound, yet with faster music there is a small section of that sound that becomes slightly blurry.



Music tests and included cable ramblings:
Before I get started I want to disclose that I have done a few more cable test choices. Where I really wanted the Quattro to be near the best it could be for these music tests. Also I typically do the music tests near the end of my reviews. With that said there is always more to do and realities to learn. And keeping this review chronologically correct I did a few extra cable rolls. You see, Dsnuts noted that the included cable is using Graphene, and that is had similarities to the Penon OSG….so I went and compared the OSG and the included cable, and guess what? Yep, there is absolute truth in that the included cable has properties like the $299.00 OSG cable. As side-by-sides with another IEM and the Quattro has the personalities much the same. What does this really mean? It means that while Penon is both a cable builder and an IEM manufacturer, they utilize their cable skills to not place any old cable with the Quattro. It would be like you were cooking and had a whole pantry of spices, you would then utilize them to make the meal you were preparing have the best taste. Now of course just like food, IEM taste is a singularly individual thing…….yet there are qualities that groups of people can agree on…….meaning this Graphene has a place and a definite purpose.

Graphene:
What it does is kind-a subdues the bass (just a little) while at the same time adding blackness which separates and gives distance in the stage to the bass tone. Graphene then itemizes the soundstage and treble in a more weighty fashion than silver, yet we do perceive an increase in midrange stage and a fluid yet enhanced treble energy. Often people will perceive this fluidness as a treble smoothness, and there is nothing wrong with that, as opposed to the energy of silver. This Graphene results in wideness of stage as well as a very identifiable character. I like to call this the Graphene character. While the ISN G4 has a taste of this character, the Penon OSG really at three times the cost, brings a lot more to the table. I was on a roll, and the reason being is I didn’t want to do the music tests with the $699.00 Penon Totem. It is a little ridiculous to combine a $399.00 IEM with a $699.00 cable. Primarily because there are many in that the Totem has priced itself out of a regular choice. So in many ways the Penon OSG was the next step up from the included cable, in fact it may be the OSG that was the inspiration for the development of the included cable? They mostly don’t fill me in on such progress, yet at times I get to see the baby in the end, minus the labor pains. So what if……..what if there was another genuinely great cable in the under $300.00 price point? Well in comes the Penon Leo Plus. Gold alloy mixed with Silver alloy mixed with Palladium alloy. The Leo Plus was the cable I settled with for these music tests. A truth to be told, it wasn’t that far from the included cable, only the Leo Plus added separation and most of all somehow added 3D forwardness to the stage, holding elements inside these sonic displays. So the reverberations were better through spatial distance noted as was the regular character the Quattro had anyway. The elephant in the room with the Quattro is the mid-bass excessiveness. Where sure there is tight sub bass, yet there is a slight issue that I always hear with a jumbling together of information inside the mid-bass zone. In my use there seems to be no amplifier or cable or ear-tip solution for this mid-bass, though we can guess Penon knows about it too, hence choosing the style of Graphene cable they went with. Yet this Leo Plus is the cat’s meow here, for a few of the very same exact reasons the OSG works well.

The included Graphene cable:



The Leo Plus and Quattro (not photographed)
I mean we know already the Leo Plus is going to trim the bass a little, with that comes slightly improved pace. A sculpturing of bass notes...........the bass is while slightly diminished, has added definition……resulting from improved tone carving. Then the midrange and treble brought into forward position in the stage, while being of correct tonality, also have a smoothness and a nice note-weight about them, while still holding air and a style of fast transients. And not surprising, the Serial was one of my best combinations in the Leo Plus review. After spending a good part of a day listening to all different kinds of music…….it was obvious that the Leo Plus was going to be my music test choice, and just to double make sure I then carried the Quattro and Leo Plus combination over to my WM1Z DAP and found that the power was still enough to make (somehow) this whole party continue on? The only explanation I have for Sony WM1Z DAP success is that it truly is an immersive 3D sound. Where the bass is big and round, the treble is tilted-up and spicy, yet it is also incredibly airy forming a halo around your head of imaging. It is the fact that this stage (from the source) has forward positioning and back, also up and down……even great right and left wideness……which made the Sony WM1Z DAP a joy to combine the Quattro with, confusingly because it was not the most powerful DAP in daily use. My only idea here is that the WM1Z is incredibly detailed and somehow those details are transferred down the line to the Quattro? I hope every purchaser of the Quattro finds their own synergy. I did find it with a number of sources and cables………..but if you look at this review it’s a diary, a diary of a madman.

And if you finally stumble upon perfect synergy, you will know it, there is no avoiding it as it is truth, truth in replay. I mean right now I have maybe too many choices, but just like Penon choosing their included cable material, options and more options are a recipe for success, how could they not be?

So this music section was a joy to write. It took a good part of a day to group the songs together, simply because it is a choice of so many well done numbers. Basically when you find synergy the musical world is your oyster to partake in any direction you choose, any genre and style of music and those sonic treats are as you remember them and better as you remember them to be, regardless of the IEM price.



DCD
Anastasis
Kiko
44.1 kHz - 24 bit
Here is the very last song I wrote about today, but this paragraph is better to be placed at the start, as this song is really what the Quattro is about. Meaning here we are fascinated by the wholesome playback of the start-off drums. Yes, they are slightly dark, only once you have gained mental acclimation here, we are in a fantasy land, a world all to itself, a world where maybe slightly too dark becomes correct, and everything is as it should be with nothing sounding off. I must reiterate about the reverberations here……..I mean there are 4 separate coincidences of that reverb? Yep, each driver holding a smooth yet careful relay of the treble reverbs, the midrange reverbs and the twin bass examples which take the cake. With all this talk of reverb you would think this sounds like a cave……but maybe it could be if your cave had perfect acoustics inside? The ride cymbal is showing its purity in form and playback by showing us micro-details of emphasis, a harder hit then a lighter one and so on at 00:15. At 00:18 the ominous bass and down beat take hold, and truly to state what the Quattro does…….it provides the mood. You know musical moods transcend technicalities and even tone, to bring the listener a form of escape. It is only when you make this musical connection that the themes and structures the musical artist intended show to make the transference over into your mind then into your emotion. It is in-fact a style of telepathy where you are ultimately inside the recording artist's mind, their imagination is in-fact your imagination now. A product of expression that can’t be put into words but only felt inside. Remember those reverberations, well we are now clothed in them………..then at 00:38 the guitar comes in. It’s a world instrument which challenges us as we have half heard this before yet something is different. There is a synth backing the instrument and going along for the ride. Lisa Gerrard makes her presence known and we knew this was coming from memory………yet this is outstanding and positioned perfectly, maybe even smoother than I have ever heard her sing, maybe I’m all done with reviewing as I’m satisfied and will never need to try another new IEM, I’m finished, maybe? These are the kind of remarks you make to yourself with the Quattro, though keep in mind it may take a little work and luck to find the zone, but once you have found it, it never leaves you.



Star Trek Picard OST
Jeff Russo
Main Title
48 kHz - 24 bit
Here we are greeted with all the joy and fanfare of a world class OST opener. And as a test I took the Quattro and Leo Plus Cable over from the Sony WM1Z DAP to the Sony TA-ZH1ES to find the differences. The way to do this is to use the exact same file that is inside the WM1Z and simply make the WM1Z DAP as the file server to the TA-ZH1ES. Now we can hear how the Quattro goes to show the differences from the handheld DAP to the desktop. Funny as these changes are ultimately both completely acceptable, and correct. With the TA-ZH1ES offering as always a more sophisticated and itemized low-end. Yet it is this synergy of both styles of playback that allow the listener with the Quattro to get that much closer to the music, and this style of music is made for the Quattro.

Here we have a synth bomb drum dropping as an opener. Yep, even at the start at 00:00 we have a deep introduction drop. Such events are actually both startling and rewarding, letting us know this OST is both a full-orchestra and synthetic. With-in the first three seconds shows us piano play and held within that is totally correct timbre. Where BAs offer a faster pace, they are never offering such real qualities as the Quattro brings. There is also a wind instrument shown, then the main theme at just 00:19 going and inviting us to join-in mentally. This welcome is much more accessible when we get mental assurance that everything is in place. A warm place which we find familiar and wholesome. At 00:27- 00:29 there becomes a wash of cymbals which find themselves at the edge of both right and left areas in the sound field. At 00:41 there is this very slight bump…..probably a stand-up bass note, a single accent to express our rhythm. And you know what…..I’m totally in the zone. A correct recording of a fabulous orchestra and it contains that energy of articulation, that charm that is the very reason we are here, to experience all the magic music can be. And I am going to repeat myself, it does not matter what you spend on IEMs, this single playback is both rewarding and unique in my experience. It’s the woody tone of the drums, the natural harmonics of the strings here, and the relationship of each and every instrument and how they blend together like a single DD driver……integrated.

Sorry, I could go on for a couple more paragraphs, but you get the message, I don’t need to make this review longer than it already is.



Theatre of Tragedy
Assembly (Remastered)
Episode
44.1 kHz - 24 bit
You know I have used this song endlessly as it is one of the brightest mixes I own. Yet I love it? And here the Quattro smooths out all the rough edges and brings the imaging from the treble details to new life. I know I’m different but I can listen to this song over and over. Plus now we can totally hear Liv Kristine Espenæs’s sexy voice coming at us in technicolor. But there is more, there is a specific rhythm and groove that shows a bounce. This bounce may be the result of incredibly fast air-like sounds that are only showing as puffs of air almost. The more I study them they are simply (high-pitched) drum machine sounds, yet not consistent in pace, as they have been processed and wonderfully aligned and then misaligned to the beat. These specific tones were the ones that we had trouble with many IEMs and mentally ignored, yet here the sounds are a welcome facet to hold and adore. The beauty here is the washes of phase shifting and fun outside the mix…......a synth way off in the distance! The fact that there is separation and involvement, playful dances of tones taking us to a climax of sorts………..good clean fun. Probably the gold here is simply how each and every instrument along with the vocals seem to go together as found in life, like if you were to hear this live or with correct playback with the use of speakers, such qualities are the stuff of complete merit and pleasure. IMO



Umwelt
Days of Dissent
Factory of Death
96 kHz - 24 bit
Ahh……..my favorite track on this album. Lets get real here, this album holds a lot of bass, only somehow everything is totally in place, where even the deep mid bass drama I was talking about seems to get along with everything heard. Now the really crazy part is the fact that I’m hearing this on a profoundly dramatic bass driven Sony WM1Z DAP…….excessive bass right from the source……so? Yet it is the changes I made with the Leo Plus Cable into which the 3D realization of midrange placement into the stage and the wonderful smooth yet bright enough filigrees of treble electronic elements are way off to the sides and totally holding transients. It is these treble effects which can make EDM too harsh or unlistenable for some, yet again we are in the zone.......heck, I can listen to anything and it will sound correct……..how valuable is that?

Priceless is what it is worth. Once again it is the cool rhythm and bounce that is the very center of musicality here. The sway and groove of how there is a sequenced style of variation with-in the beat which creates such a groove, and that element is in-fact transferred to the listener. Flowing and fun, remarkable and worth the money here as we are totally in the zone. Probably second to that quality is the total separation here, and you know that is the rewarding part, as there was a time when I was not sure of the style of review I was to write, because there was too much flat-field image positioning, so to now have this wonderful 3D space to encounter...........now that is what headphone life is about.

Build:
Such features as a resin build with air-vent come out as very comfortable. Much the same size as the Penon Serial though slightly bigger and of the same overall shape. Nozzles are just about perfect for me in length with a metal-end that holds tips on perfect. Probably the most important thing here is the form, that while having to hold a lot of gear inside, seems to really fit well and have a good nozzle angle. Each stabilized wood faceplate is unique to the individual owner with no two being exactly the same.

Packaging:

Conclusion:
Wow, what can I say? I have never witnessed an IEM like the Quattro. Now my review is only a singular listeners experience. Meaning I am only one person who hears the Quattro one way, this single way could be in-fact your way to hear it, maybe not. So to reiterate here, the Quattro is a watershed product, one the likes have never crossed my desk before. It is amp dependent like crazy, and the Quattro will show you your cable qualities, maybe more than any other IEM can. Normally this would simply mean the Quattro is transparent, and it is yet the Quattro is dependent on not only power but quality of source..................but once you find that synergy you're home carefree with a form of acceptance.

Still though there can be small areas of detail that the Quattro skims over reaching for the next tone, and still that next tone will be emotionally moving due to the purity at heart. Where Hybrids seem to not gain the authority of playback found with-in the Quattro’s walls, even more expensive IEMs showcase their drawbacks in regard to timbre and stage authority. Truth to be told the Quattro is ultimately unique, and it may take a little effort to learn to speak its language, except once communication is open, that door never shuts again, as you have found synergy. Once synergy is found there is no going back, pure entertainment, and even a taste of full-size headphones or floor standers starts to take place. If this sounds like a challenge, it is in a way, but the rewards are far outweigh the trouble.

$399.00
https://penonaudio.com/Penon-QUATTRO

Disclaimer:
I want to thank Penon Audio for their love and the Penon Quattro review sample.

Disclaimer:
These are one person's ideas and concepts, your results may vary.

Equipment Used:
Sony WM1A Walkman DAP MrWalkman Firmware 4.4mm
Sony WM1Z Walkman DAP MrWalkman Firmware 4.4mm
Sony TA-ZH1ES DAC/AMP Firmware 1.03
Electra Glide Audio Reference Glide-Reference Standard "Fatboy" Power Cord
Sony Walkman Cradle BCR-NWH10
AudioQuest Carbon USB
HiBy R3 II DAP in 4.4mm balanced
Samsung Phone 3.5mm output
Penon Tail Dongle in 4.4mm output
Simgot DEW4X in 4.4mm output
Samsung UA3 in 4.4mm output

Hello everyone, and thank you for joining me. Today, I'll be reviewing the highly-discussed Penon Quattro in-ear monitors (IEMs). I had the opportunity to borrow these IEMs from a friend for a few days, and it's worth noting that they had been used extensively before I received them, ensuring they were properly burnt-in. This is the first time I have tried a Penon iem. I was quite excited to check out what a 4DD combination sounds like. There was quite a lot of exceitemnt before it's release. There are very few iems with such configuration, one notable contender being the Oriolus Monachaa. The Monachaa has also received a fair amount of praise from those who have tried it, but the cost is a big problem there. In contrast, the Penon Quattro, priced at $400, positions itself as a more budget-friendly option.



Rating Criteria:

I want to lay out my rating criteria before we start off. For me, the primary criterion for evaluating audio gear is its intrinsic value rather than its price tag. A higher price doesn't always correlate with superior quality, and similarly, a low-priced product can give enough listening pleasure for it to be called outstanding. I consider the build, features, and, most importantly, the impact on the listening experience. The fundamental purpose of audio gear is to enhance the listening experience. So for me, this degree of enhancement in the listening experience is a key determinant in rating a product.

Rating below 4: I really won't be posting reviews of such items unless someone has asked for them.
Rating of 4: The product is good, and some users may find it more satisfactory, but it does come with a few caveats, such as price, fit, etc.
Rating of 4.5: The product is excellent and comes with an easy recommendation, reflecting its high quality and overall positive attributes.
Rating of 5: This product can be deemed groundbreaking, a trendsetter, and an eye-opener and deserves a spot on everyone's list due to its exceptional features and outstanding performance.

Configuration:

Quattro has four dynamic drivers with different specifications. It uses an independent 3-way crossover and a 3-independent conduit design for better layering performance. Here is how these different drivers handle different frequency ranges:

1 x 6mm custom dynamic driver for High frequency
1 x 8mm graphene diaphragm for Medium frequency
2 x 10mm composite diaphragm for Low frequency

The impedance is marked at 16 ohms, and the sensitivity is 100 dB. These iems need a lot of power to shine.


Design, build and fit:

In the first look, Quattro looks really nice. The shells are handmade and they are lightweight and well-built. I find it quite comfortable enough for long usage. The nozzle on the iems is on the wider side. I find a wide-bore tips to best suit to these iems. Azla SednaFit light is my usual go-to tips for wide and big nozzles. With these iems, tips selcetion is quite important as they may sound quite constrianed and muffled on a lot of tips. I suggest to try out every possible tips to find which sounds most open.

Additionally, there is a vent present on the iems which mitigate pressure buildup. I encountered no issues of pressure buildup during my time with them. I also never encountered any driver flex in these iems.

The package is really nice in the sense it ticks all the boxes. There is nothing more you'd ask for. The addition of leather pouch is qutie well thought. It comes with 9 pairs of silicone eartips catering to various . The blue cable pairs quite aesthetically. Overall, the unboxing and initial usage experience are highly satisfactory, quite aligned with the price point.

Sound Analysis:

Quattro has a very distinct, warm signature and a coloured sound. This is how these iems have been tuned, deviating from a usual standard tuning. Everything on these iems screams: warm, warm, more warm. Under this much warmth, there is a lot of rich musicality. There is a bass boost all around. This thick bass predominantly defines the signature of these iems. It's like everything sounds within a layer of bass. Some people may really relate to this analogous sound, and some may not. Let's dissect the sound even further.


Bass:

The bass on these iems is dominating. I was under the impression that the 4DD configuration meant a hard-hitting, brain-shattering bass, but my assumption was wrong. The bass definition on these iems is quite different. It's a thick and rich bass with a lot of boost in the mid-bass region. The bass is not fast, and there is a slow bass decay, indicating a more lingering or sustained bass response. The bass is very, very thick, and it's all over the frequency spectrum, dominating the way the mids and treble sound on these. This is not a hard-hitting bass with full subbass rumbles but a thick, enveloping bass where bass is spread everywhere. The subbass presence is not distinctly felt. It sort of vanishes under the impact of a thick midbass.

Mids:

The bass is all over the mid-frequency range, and there is a lot of bass bleed. This adds to the thickness in the lower mids. The vocals benefit a lot from the thickness and sound quite full—both male and female vocals. There is a fair hint of sweetness in the mids, which adds a lot to the musical timbre and tonality. The upper mids are well-bodied too, but there is a slight hint of shoutiness, which is not quite prominent. Vocal-rich songs are a treat to listen to on these iems.

Treble

The treble on these iems does not carry a lot of energy, and there is a lack of air. The treble misses the crisp nature. It's touching the borderline of a dark treble. However, for me, it is just enough treble. This is a safe zone for treble sensitive people. The tamed treble aligns well with the tuning on these iems. The bass surely kills some fun in the treble region

Technicalities:

For me, Quattro is above average in technicalities. The soundstage is more than average in it's width and depth. Imaging is also above average. The separation of instruments could be a bit better. With a powerful source, this separation becomes better, though. One good thing that is distinctive is the coherency of sound across the frequency spectrum.

Cable Pairing:

The default cable is good enough, as it brings out the true signature. These iems benefit from the good-quality silver cables. There is noticeable openness in the sound on the Effect Audio Code 24 cable. I think this cable has the best pairing of all the cables I tried. A good-quality copper cable adds a hint of warmth, which makes these iems a lot warmer, so that's not an ideal pairing, in my opinion.

Source:

With a warm or underpowered source, the Quattro can sound muffled. It pairs well with a bright source. Also, it is a sucker and needs a lot of power. On my LPGT, I have to turn the volume up to 40–42 to get a good sound out of these. With the Earmen Angel, it sounds better than with the LPGT. Angel has an ESS Sabre ES9038Q2M dac chip and is quite powerful too. With a good, powerful source, the sound is more open too. I also understand that a lot of dongles out there will not be able to bring out the best from these iems, so one should really try to pair them with a wide range of dongles to see which gives them enough juice to shine.



Conclusion:

Quattro is not an IEM built for everyone. I can understand why they can be hit or miss. The timbre and tonality of these iems are something that few can very easily connect to and find very musical. One thing I can surely tell about Quattro is that you have to spend sufficient time (a few days) to decide whether they are aligned with your preferences. On a certain day, with the right set of songs, they can sound so good and timbre-perfect that you will go gaga about them. On a different day, you are tired and not in the zone, and you choose the wrong song, and god, they would just sound awful—not to be confused with whether they are good or bad-sounding.

If you want an iem to throw a lot of precise technicalities and details, this is not the iem for sure. I have seen a lot of people say it is technically very good for an all-DD IEM, but I tend to disagree (just a little). It surely does a lot of good things, but somehow I feel it falls behind many others because of the way it's tuned. There are a lot of details getting eclisped under the bass. I think it's totally fine if it is not technically very sound. I like my iems to be either very technical or to a level where I am not bothered about these technicalities at all. If you love this signature, you may surely enjoy it and call it a winner.

Mini Trifecta??

As soon as I put these on, they reminded me of the Campfire Audio Trifecta. For me, Quattro is a mini-trifecta. I am not sure if Penon took some inspiration from the Trifecta's signature, but these two iems are quite similar in how they sound. And no wonder they both have a very different audience and fan following. Take everything a few levels up—soundstage, detailing, openness—you have the Trifecta with you. Trifecta has a similar bass all over, but it's more open and more spherical, if you know what I mean. Trifecta has troublesome upper mids, which will kind of disturb or annoy you very often if you are sensitive to the frequency. Quattro, however, has just a little hint of a similar thing but does not annoy at all. I remember I liked the Trifecta when I tried them on three different occasions but could never gain the courage to buy them, thinking, What if someday I wake up and find that it's totally disastrous? But I can surely own a Quattro and get some of the Trifecta's feel.

Lastly, I can only say it is really bold of Penon to release something like Quattro. I think this is quite a positive release. This only means they can tune their iems very differently, unlike a few brands who would just stick with a similar tuning and change a thing or two here and there. This presents audiophiles with a unique opportunity to experience a wide range of tuning variations. I am sure Quattro is a very good addition to anyone's collection. If you are the person who does not swear by technicalities on an IEM, Quattro is an easy recommendation. But, it's for sure, not everyone's cup of tea. Some may outright reject them the moment they put it in, but you can't really blame them. I rate these iems 4/5.

Penon Quattro :
4x Dynamic Driver iem

3-way crossover.
Two drivers for bass, 1 for mids, 1 for the highs.

So notice, 4 drivers but it's really only three different drivers doing the work.




Looks:
A beautiful blue faceplate. That reminds you of turquoise rocks.

Comfort:
I can fit this in my ear concha easily. Nozzle can let you deep fit the iem if wanted.

Sound:

Gear:
As you will read in the sound description. This iem is quite rounded feeling; so I used my Fiio R7 all-in-one to listen to it. As that is a more dry/intense source that this kind of iem synnergizes well with.
My main Desktop setup is already setup to give a euphonic feeling that wouldn't work with this iem.


This is a doozy of an iem:
I honestly didn't have such high expectations for coherency of the 3 crossovered drivers. But the iem's turned out to have such an amazing center-imaging.

Heck, the center-imaging is so good that it almost feels like I am using analogue chain sources. A very euphonic playback, with little even stereo imaging seperation.


Bass:
It has a pillowy midbass. Definitely not a well-rounded midbass hit. This is the only truly objective con of the iem.
Subbass rumble is fine and somehow never drowns out ahead. Subbass oddly somehow...doesn't come out as incoherent despite the bass tilt profile.


Mids:
The lower mids are colored, but remember this set is tuned to do so.

Vocals definitely tilts towards lower vocals.
A male recording made to emphasize deep vocals will come out with some weird edge to it. I.e.: Like a Johnny Cash track.

Most tracks without such deep emphasis are not as effected.

Vocals are well positioned with the rest of the mix.

Mids-Instrumental stuff:
String instruments seem to come off as if there is more lower octave stuff in the timbre. Will color a violin to sound like it's been tuned to be more baritone.


No strong imaging seperation to instruments. Just gives minimal-to-little layering between instruments, you just get pushed to focus on the later octave of stuff rather than being immersed by any staging quirks.

I have a special iem cable, the NightJar Mira, that came with my Subtonic Storm that is known for adding some euphonic mids and treble to the playback. While also centers the imaging a step further to color things more centered feeling........this Quattro already feels like it got Mira'd. o.O


Treble:
No harman-like crispness in the lower treble. Really well balanced treble in the lower parts.

Some peaking spice if you focus closely. Like heard in the higher octave stuff of vocals. Not sibilant, but you can hear a peak is happening, just it is rolling off well.
There are no problem with cymbals feeling too zingy.
The edge feeling to some strong instruments might be a little too rounded.

Treble overall is very safe. With no extra emphasis to higher-octave stuff.
Quite a nice timbre iem, but a colored timbre that is.

Conclusion:
This iem is definitely not a safe buy; to be your very first to own. It very much colors the timbre to things. A "warm" iem.

...but it is very much a fun iem to own and listen to.
Definitely do not expect to use this iem for professional work.


I don't know why, but this side-view of the turquoise faceplate looks really cool.


Size Differences:
Simgot EA1000, Quattro, Subtonic Storm




So the Nightjar Mira cable I mentioned....I tried it on.
Wow, this made the bass much more aggressive helping out this iem greatly. Heck everything is more aggressive.
Too bad it costs....yeah.
No cons to using this cable on the Quattro.

( This was my entire early impression of the Penon Quattro. Will be turning into a full review. You can tell it was an early sample due to the cable not being all blue as it is now. The cable that is shown here is actually the same cable as the all new blue cable that comes with the Quattro shown here.) You can now purchase the Quattro on Penon web site as of today.


Penon naming scheme for IEMs and cables just makes a whole lot of sense and while there is an extra t tacked in for a bit of wordplay on the QUATTRO. You all get why these new 4DD IEMs from Penon was named as such.
I am certain Penon has been working on this particular model for quite some time, the reason why I know this is because of just how popular their former 3DD IEM the Serial was and still is. The good news there is that the Quattro is not exactly a revised Serial. It is a different IEM but one with some clear upgrades on the older Serials. This being said don’t stash away your old Serial thinking these are just gonna be the replacement. Well they might be due to how engaging they sound but there is an old school soul to the Serial sound which will forever cement its place in the Penon hall of fame. I will get much more into the differences between the Serial and the new Quattro in this impression to give you good folks a foundational idea of what to expect in the new Quattro.

First there is the size of the shells. Even though the new Quattro includes 4DDs vs the 3DD in the serial. Its actual shape is very similar to the Serail shell shape. The only difference is it is a bit bulkier. Physical size feel when you insert the IEM in the ear will be no different. But it will stick out of the ears a bit more vs the Serial. I would guess the thickness of the shells to be about 3mm thicker vs the Serial shells but the actual shape and fit will be identical. Considering Penon threw in 2 10mm composite dynamics for bass I would imagine this is about as tight as the shells are going to get which includes 4 dynamic drivers altogether. For me it isn’t that these have 2 specialized bass drivers and a new 8mm graphene driver for mids that does a splendid job for the important mids. It's the new micro 6mm dynamic Penon is using for its treble that brings something new for the Quattro.

In simple terms, the Serial is a bit more laid back/ analogues in its sound character and balancing with a mild treble boost and sub bass emphasis. The new Quattro is a bit more in your face, more lively. A more engaging full bodied sound in comparison. But It goes more than that. The balancing is meticulous on this one and the way these drivers play inside the shells just works a sound that I feel is a clear example of Penons know-how to tune an IEM for musicality and full immersion.

I can hear what each driver is doing on this one and all 3 regions of sound are well represented yet clearly cohesive at the same time. The first to stand out for me in a good way was its trebles.

Ok so much to do about that new 6mm micro driver. Based on my own experiences with micro HD drivers, anything smaller than a 6mm dynamic would unofficially be called a micro driver. These things pack some serious sound. This is a case where bigger does not mean better. I have owned numerous JVC IEMs in the past that utilize even smaller micro HD drivers and I have never heard a micro driver not representing the treble end to a full extent. Since this driver was dedicated just for the treble notes. It is tuned and utilized like a tweeter for its sound profile. Its treble definition is on point.

They kinda remind me of EST implementation with a combination of BA drivers for trebles. Yes it's that good. Airy, extended with the right amount of treble sheen and sparkle. The crisp treble notes stand on its own but somehow mixed extremely well with the rest of what the other drivers are doing. Treble notes come clean, collected well extended with excellent accurate transient qualities . Jazz folks will love how the new Quattro sounds with Jazz music. Drums especially sound fantastic with this new micro driver. High hats, crash & ride cymbals sound real and distinct. The tuning here is fantastic in that you're going to hear every treble note your recording has. The detail aspect of the trebles is so very good. EST what? Lol. The treble sounds like it is using multiple drivers to attain its articulation. That my friends is a stand out treble presentation and in the best of ways.

Then there is the mids. Not that long ago you had to deal with your hohum garden variety of plastics for dynamic drivers used for IEMs but nowadays, manufacturers can reach out for all types of dynamics infused with some of the best materials in the industry. Carbon based dynamics have been around for a long time but it was when the carbon based dynamic took on a more rigid form in the graphene dynamic and even the carbon nanotube dynamic that brought a bit of a plus for the sound. Graphene sound in general has a timbre aspect to its makeup that brings a realistic tone with an added texture to the sound that is a bit unique to graphene. Vocals and instruments sound amazingly real on the Quattro if not just simply natural sounding and is this not why we spend the money to hear? The 8mm graphene dynamic here was once again very much selected for its tonal and accurate timbral character and it has most definitely paid off for the Quattro.

Its vocal texture, imaging in space, accurate timbre, mixed with a very natural full bodied tonal character and you get a clear example why folks love the Penon sound. Much like the treble aspect of the Quattro. The mids are not a second thought here. It is actually featured. Organic in presentation, natural in delivery with a musically rich tonal character is what the mids are all about. The mids have a body to the sound you guys will appreciate. And who doesn't like them some body to the sounds? Multi BA set ups for higher end IEMs does imaging and sound separation better but those multi BAs have nothing on the naturalness and realistic timbre of the mids on the Quattro.

These sound amazing for vocal performances be it male or female. The layering for its sound is a stand out. There is nothing on the sound of the Quattro that sounds flat or unnatural in any way. All of it presented in a wider than average IEM headspace with ample depth and height to the sound. Best way to describe the mids is, up in your face! Very very immersive. It has some lovely mids and the type that I personally gravitate to. You're gonna love how good the mids were tuned with this specific driver that does the mids like a boss!.

And then there is the bass end.
Well 2 10mm composite dynamics were used. More recent dynamic duos handling the bass for both the Fan2 and the 10th means these will be outputting both drivers to handle the bass notes. But with the biggest drivers to be placed in a quad configuration. So what does that mean?

The tuning was deliberate in a balanced w shaped mixed with a U shaped tuning. Its not going to be the overplayed type of bass, we are talking about accurate well balanced bass performance and much like the Serials sub bass focused.

Going back on the organic theme, but this time for bass. Bass quality and presence is ideal for the sound performance on the Quattro, but it is clearly not going to be a bass cannon. This is a balanced tuning and not one where one part of the sound is a standout. The bass here has moderate yet rangy emphasis. I would wager to guess around 8dbs in bass emphasis. Which again is a goldilocks level of emphasis for accurate bass depiction. Bass notes are not only tight, clean and weighty but is extremely well behaved in how they portray bass. It only comes out to play if it is in the track you're listening to that has bass emphasis . Bass control and tightness is key to a higher end sound and we get that in the new Quattro. What is the advantage of using two dynamics for bass?. Can’t say exactly, could be for its control aspects, could be for better bass definition. Could be for a bass end that sounds not only accurate with solid impact and is also extended extremely well on the low end. Its got a well textured bass end that has some excellent realistic bass decay in the process. Or it could be for bragging rights.

I can’t argue with the end results here. Bass is very nicely defined if not just a rich bass experience and easily morphs into any type of bass note your music calls for. I can listen to Miles Davis as well as listen to some Tribe called quest. And guess what, both genres sound on point. Its balanced bodes extremely well to all types of music.

Bass is also not playing a support role here like some IEMs do. Pound per pound you have BA bass that does 8dbs of bass and or you have dual 10mm composite dynamics with the same 8 dbs of emphasis. Which one you gonna choose or better yet which one will sound like the real deal? Sure you don't get the speed of a BA but these clearly make up for it with very accurate tonal character for all things bass. Satisfying yes but I can clearly tell they were detuned a bit to not get involved with any of the lovely mids or cause any tonal shifts. Bass quality with an accurate tonal blend with the right amount of bass decay. Bass doesn't struggle, nore does the mids or the treble on the Quattro and that is the very definition of a well balanced IEM.

By the way I just found out the included cable is a nice higher end quality silver plated copper with graphene. A simpler Penon OSG cable? Nice,

So here is what you want to know: how does it compare to Serial?
As I mentioned before. I wouldn't necessarily stash away the Serials just because there is a new sexy 4DD dynamic from the same folks that made the Serial. There is a certain charm to the Serials that make them a classic in the Penon stable. However the new Quattro throws out a more focused balanced technical tuning over the Serials. Trebles gets a bit of an upgrade. I noticed recent Penon IEMs dont have the larger 6-7khz dip for trebles like they did when the Serial was introduced. I can tell Penon learns tuning aspects from prior tunings and tries to improve on aspects of their balancing. The treble here for the Quattro has better articulation and a touch more highlighted definition over the Serial treble. Its mids has an organic tonal quality vs the slightly brighter mids quality of the Serial due to the difference in drivers and their tunings. Serials are not a bright sounding IEM per se but if you focus on vocal performances in comparison. You can tell the difference in how the drivers here influences the tonal character for music.

The Serial uses a titanium plated 8mm dynamic vs the new 8mm graphene dynamic in the Quattro. The differences are like if the Serial was using BAs it is like it was using some Knowles BAs while the new Quattro would be using Sonion BAs let me put it that way.

The end result is a more natural mids tonal performance with a more realistic timbre for both vocals and instruments.

Its stage is similar to the Serial, but does have a bit better depth and space to its sound which makes them sound more full bored and airy vs the Serial.

Serial uses a 10mm bio dynamic for bass that I have seen some folks say sounds a touch loose. I can see that but that is actually not a con for me. I listen to hip hop and R n B at times and these genres are not exactly about the tightest bass presentations.

Bass on the Quattro is a bit more seamless in how it sounds and its bass definition and control is better here. Its realistic decay with excellent sub bass texture is damn good too but not the best I have heard. But then I don’t expect these to be sold anywhere near the endgame bass texture of something like the IER Z1R for example.

Penon is not going for an uber expensive 4DD so I am sure they are working with the best they can do at the price they plan to sell it for. I really have no complaints on the bass end of the Quattro. Its emphasis for bass level is very similar to that of the Serial but with better tonal control, tightness with better quality here. Bass has a certain new found roundness and clearly defined notes that the prior Serials does not quite reach for bass. Otherwise its impact and sub bass emphasis is similar to how the Serials were tuned. That extra tonal control might have to do with this particular bass driver chosen and the use of two of

This read ended up being quite the longer un but hey. They deserve it. I have yet to fully burn them in so these are just the initial thoughts of how they be. One thing the Quattros clearly have over the Serial is that they actually sound fantastic out of the box. Can’t say that about the Serial that's for certain. If the sound improves even more so from here on with some burn in, as all dynamics need burn in imo. I can’t even imagine.