General Information


PENON SERIAL Triple Dynamic Driver 2Pin 0.78mm Audiophile In-Ear Monitors


Medical grade resin cavity, light and beautiful, comfortable to wear, no strange feeling in contact with the skin.
Semi-transparent black shell, the panel is made of stabilized wood red, blue, and green 3 colors mixed
Made by hand, the earphone shell is solid and more durable.
6mm pu diaphragm for high frequency
8mm titanium-plated for middle frequency
10mm biological diaphragm for low frequency
Resin shell, stabilized wood panels
3-way crossover, 3 tubes
Stainless steel nozzle

Brand Penon
Model: Serial
Driver: 3 Dynamic Driver
Impedance: 18 ohm
Sensitivity: 103dB
Frequency response: 20-20kHz
Connector: 2Pin 0.78mm
Plug: 3.5mm audio, 2.5mm balanced, 4.4mm balanced
Cable: 8 shares OCC & silver-plated Mixed Braided
Cable length: 1.2M

Latest reviews


100+ Head-Fier
Penon Serial Review
Pros: Awesome bass texture
Sweet, lush and warm mids
Soft, relaxing treble
Non fatiguing, non offensive type of tuning
Very natural timbre
Very high musicality
Beautiful faceplate
Cons: Average soundstage
Shell on the big side
Slightly expensive ($300 msrp)
Hi everyone. I'd like to share my very amature review of the Penon Serial in the video format. Here's the link for it:

Here's the written part of the sound impression in case my accent was too bad

The Serial has what I’d called a bassy neutral, or bassy dark tonality, where the bass will takes the spot light in this iem, while the mids and treble are on a more neutral side.

Bass: It’s good. It excels both in quantity and quality. It’s not really purely for basshead since it’s only around 10db of bass, but it’s for bass lover nonetheless. With sufficient amping power, the bass on these are very satisfying. The textures are to die for. It has this weirdly but still good layering, reverbing effect to the bass itself that’s very hard to describe. Sort of like a vintage speaker if I can say that. Those pop and rock songs from the 80s are very satisfying coming from the Serial. Kick drums, bass guitar, you name it.

The bass on the Serial are definitely on a slower side. I’d not recommend this IEM for those fast pace music genre like death metal, EDM songs or fast rock. I can even feel the driver was struggling to keep up on some of those songs.

One thing I have to say. Without sufficient amping, for example this Ibasso DC04 Pro dongle here. In and of itself, it’s a good dongle, however when pairing this with the Serial, the bass just feel very limp and not as satisfied. The bass dynamics are just gone.

Mids: The midrange is also good. It’s lush, sweet, full bodied yet very non aggressive and not shouty. Pinna gain is not too high so the vocals are not right at your face. Vocal and instruments sounds smooth with good texture to it. Piano, violin, cello, saxophone all sounds very natural

That being said, the bass does bleed into the midrange, which sometimes makes the vocal overly warm or a bit husky. The somewhat slower bass does add a bit too much note weight into some intruments

Treble: Treble is what I’d called a weak point of this iem. Like I said, it’s on a more neutral side. You can even call it dark even. There is definitely a scoop in the 6-7k region which makes this iem free from the sibilance and fatiguing. But it does come at a cost. Those percussion instruments like cymbals or hi hats are present, though they sound a bit blunted without that usual shimmering feeling.

The Serial definitely lacks the airiness or treble extension that some of you are more familiar with on some tribrids or planar iem. The treble takes more of a backstage roll to support the bass and mid. Resolution also takes a hit due to a somewhat soften treble. It’s not very sharp sounding. If you’re looking for a more critical or analytical listening session where you want to pick out those micro details, this iem is definitely not for you. It’s more for those that wanted to lay back and enjoy music in a more relaxing fashion


Timbre is one of the Serial strong points. It’s very natural, instruments is very close to real life sounding with a hint of warm and lushness to it.

Soundstage wise, it’s wide and deep, with decent amount of height. Although it still felt in your head at times, the overall stage does feel very holographic. Spacial cues or stereo, swirling effects are there

Layering and instruments separation are above average. It’s not very accurate. Vocal and instruments positioning are not very distinct. Overall the Serial is more for you to immerse into your music rather than to decipher it.


Now let’s compare this against the ISN Neo 5. The Neo 5 has what I’d called an L shaped tuning. The midrange of the Neo 5 are still apparent, yet this iem definitely lean towards a L shaped tonality.
graph (3).png

When a/b ing the Neo 5 vs the Serial, the first thing that comes out to me is the Neo 5 is a bit more sibilant compare to the Serial. Just a hint. The neo 5 also sounds sharper, crisper, sparklier. Cymbal strikes and hi hats sounds more satisfied due to additional micronuances. It’s still not at the treble head level as both still lean on a relax side of trebles. Mids are somewhat the same. I think it still has that signature Penon mids, meaning it leans on a more lush, full bodied, non-aggressive, non shouty type of midrange. Bass region is where I perceive the most differences. It’s more subbass over midbass. I’m bias towards L shaped tuning, I feel like the Neo 5 has better textured, more satisfying type of bass. It’s a tad tighter than Serial’s

Timbre wise, Serial I think is better. It just sounds more natural compare to Neo 5

Stage wise, it’s decent. It’s wider but less depth compare to Serial. Both of it are still fairly intimate and inside your head type of stage. Instruments separation, layering is more or less on par

* Additional note that i wrote after i finished making the video
- Source: Chord Mojo also has a very good synergy to the Serial. The Mojo also brings out a similar sound quality to my HappyAudio dac/amp stack, that very satisfying bass and mids.

Penon Serial vs Simgot EA500.
graph (4).png

The EA500 is very different compared to the Serial. EA500 has a neutral bright tonality. The bass doesn’t reach as deep compared to the Serial, although the bass does feel faster on the EA500. Mids sounds more vibrant, a bit shouty with the EA500, likely due to a higher pinna gain. EA500 sounds brighter overall. The treble sounds sparklier, but also a bit more harsh compared to the Serial. Timbre wise, Serial is definitely better than EA500. The EA500 feels lighter in note weight with more metallicness which affects the overall timbre. Soundstage and imaging wise, i would have to say the EA500 takes the win here
IMG_20231119_162342 1.jpg

Penon Serial vs Tanchjim Oxygen
graph (5).png

Both have a very natural timbre, similar bass quantity although Serial bass texture was more satisfying than the Oxygen. It feels visceral, reaches deeper, rumbling harder whereas Oxygen's was a bit softer. The 6k dips in the Serial with a slightly lower pinna gain makes it less fatiguing to listen over a long period of times. I also listen to a higher volume on the Serial. Where the Oxygen wins is in its upper treble response and the technicalities. Those percussion intruments are brought more forward, they sound more apparent, vibrant with more shimmer to it compared to the Serial. Soundstage is wider, layering is slightly better on the Oxygen.

Penon Serial vs Dunu SA6 Mk2
graph (6).png

Almost exact opposite driver configuration, but easy pick nonetheless: Penon Serial takes the win. The Serial is more musical, has a way more natural timbre, stronger more rumbly bass, although the bass on SA6 Mk2 is faster with less body to it. Vocals sound more lush and natural compared to the SA6 Mk2, although i'd have to say both have very good sounding mids, just portrait very differently. SA6 Mk2 sounds more airy, has more forward treble - almost too forward - part of which contributes to its not-too-natural timbre when facing against the Serial. Microdetail goes to the Dunu SA6 Mk2

Penon Serial. Although it's no where near perfect, it is a very good sounding set nonetheless. This is for those that want an analog sounding set with warm, lush with natural timbre iem to use for those relaxing session, where you just want to melt into the music. Highly recommended.
Those that are treble heads, or are chasing for absolute microdetails or highly technical sounding iem, i'd have to tell you to look other way.

That's it for my review of the Penon Serial and thank you for reading.
Nice review! The set looks so familiar! :stuck_out_tongue_winking_eye: 🤭 🤣


Previously known as TheDeafMonk
Penon Serial - A Vocal Drug
Pros: What I Liked:
-Included Accessories are top notch , case , cable, tips, cleaning brush all with minimal packaging well done PENON
- 0.78 2 Pin termination for easy cable swapping
- Sibilant free highs great for treble sensitive people.
- Musical unbashful colored sound signature presenting on the warmer dark side
- Good bottom end that blends into the mix for a more fun IEM vs a neutral tuned
in both Male & Female are silky smooth in a organic and lush musical way
Cons: What I Though Needed Improvement:
- Shell shape needs more shape with the shorter nozzle it was hard to fit and get a proper seal greatly effecting the bass.
- Sub bass has presence but sounds like more 60hz and up in the lower mid bass region
- Bass for me did not hit my preferred snappier attack and release and adds too much note weight into male and female vocal region
- Female vocals suffered the most with added heft making vocals sound more masculine
- Lacks stage height and depth as well as instrument definition and realistic timbre because of relaxed upper mid range and highs.
- Wont be for serious bass-heads not treble-heads nor Neutral seekers.
- Not a all-rounder and some will find the extra coloration too much for their libraries.

"When a IEM makes you totally forget your listening to anything other than music that’s a very powerful thing, and extremely rare at any price in this hobby!"

Now let's get into it: The Techy Stuff
Triple Dynamic Driver Consisting of:
1x 10mm Biological Diaphragm for the lower frequencies
1x 8mm Titanium Diaphragm for the mid frequencies
1x 6mm Polly Urethane Diaphragm for the highs
Shell is a Semi-transparent black shell with the top made by hand stabilized wood pieces that is unique to each IEM!
The Serial uses sound tubes to carry the sound to the stainless steel nozzle
A 3 Way crossover divides the frequencies to each respected driver.
Sensitivity is rated as 103db for each watt of power used.
Impedance is 18 Ohms
Cable can be chosen as either 3.5mm SE, or 2.5mm or 4.4 Pentagon Balanced Options and is a 8 core Silver Plated & OFCC mixed braded cable.

More information can be found here and non-affiliated link:
Purchased privately form another Audiophile.

Subjective Part of my Audio Review -

I share my impressions as I hear them with my ears.
As all our ears are different shapes & size so what I hear as bright or bass heavy -you might hear as dull and Vise-Versa; just something to be mindful of.

What makes my ears happy as a sound signature is a slightly more aggressive L shape. I love my Bass Sub and Mid Bass love it all actually; and in large quantity. With the Bass, I prefer a faster decay the faster the better so as to not bleed into the mids., I am treble sensitive and prefer a slightly darker warmer replay with good treble extension.

I prefer the fast speedy bass of the Beryllium Coated Driver of my Xenns Mangird UP with a Beryllium Coated Driver. Of course, there are exceptions in the market - as I also find the bass of the Bio Diaphragm used in the Yanyin Canon special - has some special sauce like an 8" subwoofer that feels like a 12" Has the slam and some serious sub-bass! And the super cool Copper Alloy Shell IKKO Obsidian OH10 does some magic to the bass.

My music Library is widely varied from; Metallica, Great White, Cowboy Junkies, Pink Floyd, Adelle, Melisa Ethridge, Fleetwood Mac, Five for Fighting, Manskin, Poncho Sanchez, Jimmy Smith, Chopin, The Crystal Method just to name a few. When not listening to my test tracks the majority is Jazz or Alternative Rock especially Female Rock. Lorde, Halsey, Alanis Morrisette, Evanescence. All depends on my mood.

Sources: E1DA SG3, Shanling UP5, Geshelli JNOG J2 with AKM4493 chip. Truthear SHIO (Dual Cirrus Logic 43198 DAC Chips)
DAP/TRASPORT: From Lenovo Laptop with Tidal, iBasso DX160 (Dual Cirrus Logic 43198 Dac Chips), Samsung S22 Ultra with DSD Files.
Amps: LoxjiP20 & XDUOO MT-604 tube hybrid amps and Topping A90D Amp 4.4 Pentagon Balanced Out - Unless stated
Tips Used for the Hola were the BGVP 07 Tips I found for Best Result and subjective: Short Wide Bore are recommended to maximize stage my preference at the expense of perceived bass enhancement with narrow bore tips.

My Format has changed with community feedback. So now I will list the music tracks I used & why with my musical impressions of the playback using that track. I hope this will give you some context for my library and give you some contexts to compare using the same tracks.


Let's Begin:
Total Time 2:25:00 35 Tracks

#1 "Beautiful Blue" by Holly McNarland
(I love Holly's vocals should be crips clear vocals with the right edge to here vocals)

#2 "Give Me One Reason" Tracy Chapman
(I love her voice and the way it is recorded listen for the strums on the guitar - I have seen Ms. Chapman live a few times; so In my mind, I try and remember how she sounds like 5ft from me as I was blessed to experience)
"Same as above"

#3 "Paradox" by M.E.B.
(Great female vocals listening for accurate piano at 0:11, bass hits at 0:28 and vocals at 2:00)
"Very nice weighty hits, perfect weight on voice."

#4 "Rock Me" by Great White
(80'S Baby, Double Kick drums at the beginning of the first track I am listening to how fast it hits how solid is the bass and what's the decay like. An ideal replay here would be fast, powerful bass with nice note weight to feel it in your chest so to speak if you were at a concert.) ( With "Rock Me" same thing but I am listening for the bass guitar drops on this track it should be quite low)
"The Serial was made for this kind of music"

#5 "Wheat Kings - Remastered" by The Tragically Hip
(Sense of stage and Male vocals)
"So smooth just plain musical Instruments were Fantastic, So smooth but stage feels like you're in a small club"

#6 "Chemical Mentalist" The Crystal Method
(Bass, more bass fast and lots of it - How does it do end of the story - Huge Smile or poo emoji?)
"Thump Oh Yes , goes go low but not with authority"

#7 "Its Time" by Labrinth, Sia, Diplo
(3 very different singers and their voices come together. I use this because it’s a cool track and at higher volumes lesser IEM's get sibilant. Piano doesn’t get washed out and Vocals at 2:30 should blow your little mind)
"So powerful , the loudest I have ever played! Piano was perfect"

#8 "All My Friends Are Here" Joe Satriani
(In this track you can hear Joe playing dead Center with the busy and very separated L & R licks added in and then he brings you back to center with some crazy and very hard-to-play Descending A Major rifts! As Joe described this song as "A rock guitarist trying to control a wild beast"
"Not enough depth to give you the wow factor of this song needs more high energy and layering. Did the A major well"

#9 "The Antidote Is In The Poison" GoGo Penguin
(Modern Jazz at its best. Powerful, Dynamic track full of emotion and snappy bass. Fantastic track to listen to how well Micro Dynamics are conveyed and get a good sense of the IEM's ability to convey that to the listener.)
"Bass is too fat and textured"

#10 "Angel" by Massive Attack
(Say it with me - massive textured bass drops )
" Misses the low drops but once the vocals show up you forget everything else"

#11 "Bring Me Some Water" by Melissa Ethridge
(I like this track to hear Melissa's voice and see if the transducers (speakers) reproduce her voice to how edgy I think it should be.)
"Guitar sounds great Vocals a tad thick"

#12 "A Whiter Shade Of Pale" Annie Lennox
(A Bach-inspired Hammond Organ M102, I seriously love it and its unique sound with Annie's voice this is so cool)
"The sense of stage is missing the Left to Right Pan is weak. Vocals are perfect and organically lush."

#13 " So Cold " Holly McNarland
( Vocals on this track are further back in the track and L & R upfront good track for testing depth of stage and vocals - Sub Bass at the very beginning has a nice drop.)
"Goes low but sub bass is too lean again no depth just one plane L+R."

#14 "Shape Of My Heart" Sting
(in this track I am listening to the sound of the guitar pulls and slides. How well does the IEM give an emotional presentation of the mix between the vocals and the bass.
"Vocal weight here is great but pulls need more pluck shows the coloration in a good way."

#15 "Wishing You Would Stay" by The Tea Party with Holly McNarland
(Love this track. With this song and this band, it was the first time having a guest vocalist. Holly McNarland has a great voice and I have seen her live a few times front and center getting sweat on. Listening for Holly's voice being forward in the mix and not sibilant.)
"Perfect and impactful"

#16 "Avenue A" Tom Cochrane and Red Rider Live from the Symphony Sessions
(This track with more resolving IEM'S you can hear the guitar pulls and slides with a sense of open spaciousness and grandeur)
"Guitar sounds great very intimate in the way it should present does not sound like a big concert"

#17 “Eden” Hania Rani
( The way Hania has recorded this track with the mics on the strings in the body of the piano is incredibly unique and such a unique presentation you can hear the string's tension at the beginning, Bass kicks in at 1:40 and goes low that’s what I am listening for)
"Wow piano one of the best replays of this song I have heard except the 64 Audio U12t at 10x its price. Bass goes low but not to bass head levels as it should."

#18 “Summertime” Louis Armstrong & Ella Fitzgerald
(This Track has both legendary artists Simply listening to Louis and Ella’s voices and of course, the Piano and trumpets how accurate and lifelike )
"Trumpets were wow as were both vocals very nice"

#19 “Blue Train” Poncho Sanchez
(Trumpets here are silky or should sound that way with good timbre, overall mix how does it present, and of course Poncho’s drums )
"Very good super fun + musical all the instruments was mental. Mental Instrumental!"

#20 “ My Girl “ Royal Philharmonic Orchestra
(Listening for instrument placement and stage and this track gives a good sense of dynamics and excitement with lots of dynamics in the mix)
"The macro details were great but not enough depth and the way the bass hits from Right to Left as it comes towards you is mostly missing"

#21 "Iconic" by Alanis Morissette
(More edgy female vocals to give you the chills)
"So Nice is the voice correct or just lush hard to tell keeps you guessing"

#22 "The Day That Never Comes" Metallica - Live with the SFO from S&M2
(Big open stage good depth of stage excellent recording with a excellent orchestral opening)
" Missed replay on this just not enough stage to bring the sense of venue grandeur."

#23 "Tricycle" by Flim & BB's
(Turn this one up and wait till 0:28 seconds- Have Fun Dynamics test)
"No attack to make this track what is should play back correctly"

#24 "Team" by Lorde
(Female vocals if your lover of those this is a great track)
"Vocals are terrific no stage or enough to make this track super engaging"

#25 “ Wake Up “ Oliver Mtukudzi
(Oliver Mtukudzi is an African Musician and prolific guitarist and Vocalist. He sings with a mix of South African styles sometimes in English sometimes mixed like in this track and includes the traditional drumming styles of the Korekore. TUKU MUSIC at its finest – Listening for vocals, bass lines, and clarity – and because it is just fun! Right at the beginning you have some very cool snaps and instrumental)
"Vocals so engaging"

#26 "Brothers In Arms" by Dire Straits
(Intro and dynamics or distant thunder, and Iconic Mark Knopfler's vocals Bass hits at 2:12)
"The opening was missing its attack and the bass is too weighty vs fast hits it needs"

#27 "Keith Don't Go" - Live Version by Nils Loftgren
(Acoustical Guitar absolutely amazing recording - Tonality and male vocal clarity)
"Serial didn’t play the guitar correctly missing some sharpness but again vocals are first class"

#28 "Somebody I used To Know" by Goyte & Kimba
(A huge stage and Vocals listen for excellent separation and stage, Vocals at 1:38 and female 2:38 and micro-dynamics
"Very Smooth"

#29 " Flight Of The Cosmic Hippo" by Bélla Fleck & The Fleckstones
(Excellent recording and Bango bass should hit hard and low with nice mic of piano weight)
"Bass is fat and meaty the banjo sounds too muted"

#30 " New Orleans Is Sinking " By The Tragically Hip."
Listening to Gord's Voice without enough MB his voice will sound thin on this song.

#31 "Electrified II" by Yello
How well does the playback just trip you out and pull you into the stage and presentation think Ferris Bueller's` Day Off on LSD
"Missing the top end enough to make this track electrified!"

#32 "Fever" bu Malia, Boris Blank
( Kind of a techno version of a classic with great female vocals and nice bass line throughout )
"Smoky vocals so enchanting"

#33 "Poem Of Chinese Drum" by Hok-man Kim
( A poem with drums just a excellent track to hear how percussions sound and there tonality)
"Missing the speed the Serial driver or tuning really shows weakness here"

#34 "Song Of the Stars (Remastered)" by Dead Can Dance
(Sub bass line at beginning goes low and the whole track is excellent to test stage and micro dynamics
Constant Left and Right with Center vocals is very trippy)
"Does the sub drops but not enough to tingle your ears"

#35 "Don’t Make me Wait" By Sting and Shaggy
(Listening to these iconic male vocals and correct tonality"
"Bass is too thumpy but vocals are perfect"

Firstly let me state that the Penon Serial is a special IEM.
When a IEM makes you totally forget your listening to anything other than music that’s a very powerful thing, and extremely rare at any price in this hobby!
The Serial defiantly has the Penon House Signature Sound with its Lush, Organic colored sound. Vocals come off so effortlessly and musically that the Serial is a aural pleasure to listen to.

The Serial was a very hard to review IEM I must say that because when you are going through your playlist at trying to pick it apart and write down your impression, I kept getting pulled into the music and had to start again.

Overall the Serial can be easily called a L shape sound signature with a Mid Bass over Sub Bass sound.
The Bass is more thumpy and fat rather than textured with speedy & fast hits. The Attack and Release is on the slower side making the bottom weighted more towards adding in something extra to male vocals.

Female vocals also suffer from this but not when you are just listing to music here again is that special magic the Serial has. All vocals just sound musicial when not critically listening and or doing a A&B comparison.

Mids are weighted and present dark or warmish being recessed slightly and makes you pay attention to singing.
I found the highs to be present but not with energy or sharpness to distract you from guess what VOCALS!

Instruments again on just listening to music sounds natural and warm and correct. It wasn't again until you were really trying and critiquing that you would think something was off on its timbre and overall tonality.

Layering , Instrument separation, sense of stage Imaging and details are not the Serials strong suits and not its intended tuning so the Serial cant really be faulted here as it is not trying to do these things.

Overall I would ask you if Is the Serial for you? Do you like laid back warm sounding replays and prefer weighted bass over hard hitting or extremely powerful low notes.
Are you looking for a Lush and very musical experience and don’t particularly want a super detailed sit down chill session?
Then Buy the Penon Serial it really is lovely.

It was in the end not for me just because the fit with the short nozzles and the speed of the bass with a lack of more sub bass just didn’t ring my bell.
I also need bigger stage and excitement to keep my brain engaged or I will fall asleep and drool all over the place.

Thank you for taking the time to read my review.
My Video review is here:

SIMGOT EA500 with Bass Vent mod:
The Simgot has my preferred faster bass response that I look for with more texture and impact. The EA500 goes much lower and has tons more sub bass energy.
The Serial sounds like it has too much mid bass compared to A&B listening comparisons. The Stage , the dynamics and the imaging and layering are also miles ahead of the Serial.
The vocals are more forward in the mix and not as smokey and lush as the Serial where it really shines.

ZVX Hits harder but doesn’t show the finesse in texture than the serial. I found the ZVX to be more engaging because of the added highs and stages better with Instruments being more lively.

Thanks so much, Cheers from the Tone Deaf Monk.


  • lgd-4033-post-.jpg
    62.4 KB · Views: 0
  • 20230402_154721.jpg
    397.5 KB · Views: 0
  • 20230402_154648.jpg
    3 MB · Views: 0
  • 20230402_154538.jpg
    2.8 MB · Views: 0
  • 20230402_154520.jpg
    3.7 MB · Views: 0
  • 20230402_154443.jpg
    1.1 MB · Views: 0
  • 20230402_154420.jpg
    2.2 MB · Views: 0
  • 20230402_154407.jpg
    2.4 MB · Views: 0
  • 20230402_154312.jpg
    2.1 MB · Views: 0
  • 20230402_154721.jpg
    397.5 KB · Views: 0
Last edited:
Let me see if I can fix the link thanks.
Woah. So modded EA500 beat the Serial by a mile? Really?
marcos antônio
marcos antônio
what do you think of his sound and is it really good as everyone says? my brother has the Globe and I like it a lot I think it's very good with excellent bass and mids too and high not fatiguing and it has a good attack speed in the bass , I'm interested in buying the Serial but they say it has bass a little slow and can congest a little for Metal what do you think?


Headphoneus Supremus
Penon Serial the triple dynamic allrounder
Pros: - Musical
- Natural Timbre
- Engaging Bass
- Romantic Mids
- Neutral/relaxed treble
- Wide Soundstage
- Design
- Accessories
Cons: - Microdetail (still its some of the magic)
- Upper frequencies slightly dark
Penon Serial the triple dynamic allrounder


This is my first Penon product if you do not count ISN, I bought it with my own money. All impressions below are my own subjective thoughts after a few months of use.

Description from the Penon website

Medical grade resin cavity, light and beautiful, comfortable to wear, no strange feeling in contact with the skin.

Semi-transparent black shell, the panel is made of stabilized wood red, blue, and green 3 colors mixed

Made by hand, the earphone shell is solid and more durable.

6mm pu diaphragm for high frequency

8mm titanium-plated for middle frequency

10mm biological diaphragm for low frequency

Resin shell, stabilized wood panels

3-way crossover, 3 tubes

Stainless steel nozzle


Brand: Penon

Model: Serial

Driver: 3 Dynamic Driver

Impedance: 18 ohm

Sensitivity: 103dB

Frequency response: 20-20kHz

Connector: 2Pin 0.78mm

Plug: 3.5mm audio, 2.5mm balanced, 4.4mm balanced

Cable: 8 shares OCC & silver-plated Mixed Braided

Cable length: 1.2M


18 months warranty

Penon has quite a big lineup of IEMs and cables, and continues to make new IEMs and cables every year. The last IEM launch of them being the Impact priced 2500$ and from first impressions competing even higher in price. This is something that is often the case with their releases, they almost always compete with sets more expensive.

Penon FAN $139 - 10mm Single Dynamic Driver
Penon FAN 2 $279 - 2x 6mm DD bass driver + 2 BA Drivers for mids and treble
Penon Globe $339 - 10mm DD doing low end + 2 BA Drivers mids and Highs
Penon Impact $2499 - 10 BA Sonion BAs and ESTs
Penon Legend $1299 - 13 BA Sonion and Knowles with tuning switches
Penon Orb $249 - 10mm DD + 1 BA
Penon Serial $299 - 3 DD drivers
Penon Sphere $159 - 1 BA
Penon Volt $799 - 10mm DD + 2 BA + 4 EST
Penon Vortex $219 - 10mm DD

About me and my gear used for the review

My audio preference is neutral with sub and mid bass boost, mids can be forward but not too much. I can also handle some treble spikes if it's not excessive. I am a believer in having different tuned IEMs for different genres or moods instead of chasing the single perfect one.
Main music genres I listen to are Metal, Electronica, Jazz, indy rock/metal, R&B, Pop. I am a music lover, and can listen to almost all the genres out there. I have been into music gear since the mid to early 90s, gifted some big speakers at an early age. Then moved more and more into headphones with the Koss Porta Pro and a Sony DiscMan and MiniDisc.

I have tried playing many instruments over the years from piano to sax and have a feel for what's a natural tone, but not a talent in playing. My wife has also played many instruments from string instruments to wind while has the talent part I lack.

My current standard in IEMs is SA6 and Penon Serial. One all BA with near perfect tonality for me, and the Serial with also a near perfect tonality for me. That is also the IEM getting reviewed here, so a little spoiler.

Gear used in the main rig is Topping E70 DAC together with the Topping A90 Discrete headphone Amp. I also have a Schiit Lokuis I can swap to if I want to do a little EQ.

I have also used the Feliks Audio Echo, one of the more silent OTL amps.

Portable gear has been Tempotec Sonata HD II Dongle, Hiby R3 Pro Saber 2022 DAP, Quidelix 5k DAC/AMP and Xduoo XD05 Plus DAC/AMP.


What the Penon Serial is:

The standard in IEMs around this bracket is Hybrids or in rare cases a single dynamic driver IEM. The Serial uses 3 dynamic drivers of different types and size, with crossover so each DD has different parts of the frequency response to do.

The low end is handled by a 10 biological diaphragm, the mids with a 9mm titanium-plated diaphragm and last the 6mm pu diaphragm doing the highs. The magic part here is that all the drivers are dynamic drivers and masterfully put together so If you asked me I would have believed it is a high end single DD IEM. A part of this working so well is the tubes from each DD deliver the sound straight to the nozzle.

The face plate is stabilized wood and not one Penon Serial looks the same since they are handmade and painted. The resin is semi translucent and with some lighting you can see some of the magic inside.

It has a safe form factor with medium size shell and medium length nozzles, this should sit well in most ears.


Package and accessories

You get the yellow product box, cable, cable pouch, 3 sets of tips(S.M.L), leather strap, Blue storage box with zipper, little brush, shirt clip and the IEMs itself. Not too shabby if you ask me.

The case is just the right size and can fit the IEMs with cable and a small dongle, zipper is in metal and to me makes me afraid of the cable coming in between. The color is also quite striking, but blue is the color that Penon goes for with their storage cases.

The included tips are of good quality, from wider bore to smaller. If you don't have a tip set you love you should be happy here without the need to buy anything. Personal favourite is the green one.

Penon CS819 is the cable itself and is a very good value and performing cable. OCC and Silver Plated Mix. This is one of the cables I recommended when in need of a cable under 50$, it's soft and flexible. Great weight not being too heavy or too light, the connections and splitter are good quality. It sounds great, so when in need of a cable that's natural sounding not changing the signal.

This picture is taken from Penon listing, since I never took a picture of it all.

So how does it sound

Natural, bold and sensual is the first that comes to mind. The sound is coherent with no gaps that makes you want more, when you put on any type of genre it will usually sound great .

I have different types of headphones or IEMs for different purposes. The Penon Serial breaks that for me. Yes maybe I would have wanted a little more of that or that for something, but the thing is nothing is wrong or lacking so I tend to not have that thought. While my favourite genres on the Serial are Darker Metal, Prog Metal/Rock, Melodic Metal and so on.

I had a talk with another reviewer(Tony), he had a good analogy for the Serial: it is like the good big vintage speakers. And I 100% agree with this, the big speakers with 12-15 inch woofers. Not the most technical sounding speakers compared to today's standards but perhaps more musical and thick sounding. Do not take this out of context and think it lacks details, it shows everything with good detail, soundstage and imaging. Still some other sets will give you better microdetails if that's your thing.


First off what is Timbre?
From the Wikipedia:
The Acoustical Society of America (ASA) Acoustical Terminology definition 12.09 of timbre describes it as "that attribute of auditory sensation which enables a listener to judge that two nonidentical sounds, similarly presented and having the same loudness and pitch, are dissimilar", adding, "Timbre depends primarily upon the frequency spectrum, although it also depends upon the sound pressure and the temporal characteristics of the sound"

First minutes of trying a new set of gear, what I always listen to is how natural and musical it sounds. Much of this goes down to how I perceive the Timbre.

Penon Serial has a very natural sounding timbre, instruments sound very close to what they do live. It gives a little extra warmth making it lusher and more romantic. So not 100% right, and I like this approach.

It reminds me of some wood headphones that also have the same type of timbre.

The timbre is often more correct to me in DD drivers, so here we get 3 drivers all DD. This does its magic making them sound coherent from the low end to the high end. BA can also do a good job here and sound natural, but here again is more easily done in all BA IEMs rather than hybrids.

Details, Soundstage and Imaging

As mentioned before this is not the most detailed monster out there, it has drawn a line where you get good details but not too much where the experience of the song is ruined by a bad recording.

This means it also pairs well with music that is old and not up to today's standards. With good recordings I can adore technical gear showing every nook and cranny. Love the headphone ZMF Verite for this, while at the same time it's not headphone where I put my library on shuffle and enjoy. This is where Serial is a good companion.

The soundstage is presented more forward than most single DDs IEMs, having some nice depth and a little outside your head. What is the most impressive is how wide it goes , especially far out to be an IEM. While someone is always going to disagree, the soundstage is a subjective impression that differs from person to person . This is still an IEM and not an open headphone with a vast soundstage.

As for imaging there are no gaps I can notice, I do think that this is a place where IEMs often do it better than headphones. Many headphones will have some dead zones where the image is disappearing. While I mostly do my tests with music, I also play FPS shooters. The soundstage and imaging does a fine job pinpointing where sounds are incoming from.

Michael Jackson with Thriller is a good and fun sounding track to test soundstage on. Good separation of the sound and different depths being shown. Feels almost like a binaural recording.


Yosi Horikawa with Bubbles is also a masterpiece for testing soundstage and imaging.
It's also very technical as much is happening at the same time here, Serial in my opinion does it as a champ.



The bass is elevated but not a basshead amount of bass, I would say it has struck a good balance between fun and not overpowering the mids. This comes back to the 12 inch vintage speakers, the bass has a large sound. Not the fastest and not the slowest, it's in a good middle ground with some good sustain and decay. It can easily hold up with the speed in Psy Trance and other fast electronica genres.

If I would say a little negative it's that I would have preferred a little more sub bass, while the mid bass are probably what I find to be perfect amount and balance. Most IEMs coming out sound to lean in mid bass, specially the Harman tuned ones. Harman target while having a good sub bass rumble, lacks emotion and attack. I would say the soul of music is in the midrange and the mid bass, it's what makes you wanna dance.

In case you are a basshead this is not the amount you are looking for, but it has the definition and bass technicalities that might set your other bass head IEMs to shame. Especially if you EQ the sub bass up a few dB.

Its very detailed bass and sounds very natural, check out some killer bass lines from Victor Wooten and you can see what I mean.

Angel by Massive Attack
Good sub bass slam and it digs deep into the lowest frequencies, could have wished for a few more dB at the lowest notes. Still I have other IEMs for this if the perfect sub bass is needed. I do think it handles it very right overall.

Moth - Dyacide remix by Epsilon, Dyacide
Immersive ambient electronica, with a fast rhythmic bass going also having a heart pumping sub bass in the back. This is a track I personally hate on slower IEMs or the ones who don't have enough mid bass slam. Serial can easily follow the rhythm give me pure satisfaction here. Great track overall, just be sure to not push your volume too much as you will get tempted on the Serial.


So What by Miles Davis
Well renowned track, the Double Bass is played through the whole track. Here it's not too forward in the mix, with a basshead IEM this arrangement sounds wrong to me. With the Serial it hits just right showing good bass separation with just the right amount.


First off, if we say that the mid Frequency is from 300 Hz to 4,000 Hz it's easier to understand what I'm expressing in this part. Mids are where vocals and almost all instruments are, around 80% of the music is within the midrange. Many say that the soul of music is in the midrange making the success of a set of gear. I do agree to some part with this, it's also where too much makes the sound fatiguing or shouty. While too little can make the sound boring.

The midrange is very much to my preferred liking with a small forwardness that makes both instruments and voices come alive.

The lower part of the midrange is fairly neutral, maybe some small warmth.
The upper midrange has some extra energy, giving some good energy to music. This combo works very well for me making vocals not shouty or tiresome, while giving some warmth to the sound signature. Just borderline increased so it's not fatiguing with brighter jazz or rock.

Stretch your Eyes by Agnes Obel
The fullness of Agnes' voice together with the Cello is very intimate and magical. I do feel the tonality in Serial shows the song very spot on.

Trade it for the Night by HAEVN
Very good track and Marijn van der Meer has a beautiful and hypnotizing voice. This is a goosebump song on Serial and lets the midrange qualities flourish.


About Today by The National
One of my favorite tracks, I have played this on repeat over and over for years. It's both a sad and intimate song, the cello playing in the background giving many emotional feelings. This is one of the tracks I can notice that male voice is perhaps a small amount forward with the Serial, still as mentioned its minimal. I can listen to this track forever with the Serial.



Can first start with saying that the Serial is sibilance free, it has frequency dip from 4k to 8k making it quite relaxed. While still keeping some good air for the upper harmonics. Would call it a relaxed treble with good extension.

Humming by Portishead
Another on Head-fi recommended my try this some years ago when I was testing a headphone for how fatiguing the treble is. It has lots of weird elements, and sounds almost trippy. There are lots of unpleasant sounds that are shown if the treble is too forward or harsh. The Penon Serial does this as a champ. Personally I can take much treble but this track with the IEM Tipsy Ttromso is almost painful in comparison.


Claire de Lune by Kamasi Washington
This is a complex track with loads going on, this also tests brass instruments from the midrange. While everything sounds very right this is borderline too much and a faster IEM does this track better. Still it shows good separation of the instruments, and is not that slow that it smears the sounds together. This is also a track where forward midrange can push the Tenor Sax over what's pleasant. Not my favorite track on the Serial because of what is mentioned above, this impression is also due to my favorite cable that pushes the mids a little forward.

Air performed by Anne Akiko Meyers on violin.
Air is breathtaking here, the violin feels alive. And the airy treble is clearly present, I'm not a person who listens much to classical music. Still from what I see as a perfect representation with the ZMF Verite, the serial does lack some detail and airiness. But this approach is not wrong and is still tastefully good, where you just don't pick apart every nuance.

Gear and cable synergy

I have tested the Penon Serial with portable dongles, portable amps and desktop gear. It scales very well with higher end amps like the Topping A90 Discrete. I have a preference with cleaner sounding amps on the neutral side over warm or dark gear together with Serial. It is harder to drive than many other IEMs but all the dongles I tried have done it loud without getting anywhere close to halfway in volume.

One unusual pairing that has been quite fun is the Feliks Audio Echo tube amp, this amp is very silent and had sound on the more neutral side to be a OTL.
This combo gives even bigger lushness to the sound and makes the bass hit even harder and bolder, very fun with electronica and dark metal music.


As for cables I have tried the DUW-03, Penon Mix, ISN C2/S2 and NiceHCK Silver Cable. Favourite being the ISN C2, while the DUW-03 is a perfect companion and a clear upgrade cable when going from the stock cable. While the Mix also is similar it has some extra treble energy compared to the DUW-03.

My favourite ISN C2 gives some extra fullness to the sound similar to what my tube amp does. You also get modular connections making it more versatile with DUW-03, Mix and C2.

The changes are small and if it's because it's placebo or not doesn't matter for me.




And yes this is not a dynamic driver and not the same price group. What makes me put them into the review is that it's also a multi single type driver, 6 BA drivers with a nice tonality that many know about. It's also one of the few IEMs I own.

The SA6 has a more neutral sound, with a more clean clinical timbre that is mainly due to the BA drivers. Since its BA it's also a very fast IEM, and never really gets confused with fast technical songs.

Serial is more musical with more body to both the low end and mid range. Treble is more refined and forward on SA6, airiness is similar.

Soundstage is wider on Serial with around the same depth on both. Micro detail in the imaging goes to SA6.

They are very different but at the same time share a a clean unobtrusive sound, one being more on the cold side and the other on the warm side.

Penon FAN 2
Hybrid consisting of 2 DDs for the bass and 2 BAs for mids and treble.
This is a more neutral IEM with less warmth to the bass and mids compared to the Serial, as for treble detail and energy they are not far off each other. While the BA does make the timbre be closer to the sound of the SA6 in the mids and treble.

The low end is faster and less boosted in the FAN 2, while the Serial has harder sub impact and perhaps better note separation in the sub bass notes. The Mid bass is the other way around with more slam in the FAN 2. Both do the low frequencies great.

Mids are similar in how forward voices and instruments sound, while the timbre is different. I like both and would say that the Serial is more romantic while at times with brass it can get too much that will not happen on the FAN 2. Also a note on the deepest voices of male, there is some forwardness on the FAN 2. It's not unpleasant, but on some tracks can seem unnatural in comparison to the Serial approach.

The upper mid range is actually a little relaxed on FAN 2, they have the same amount of treble extension. Maybe tipping my hat off to the FAN 2s treble, this might also be due to the fact that the FAN 2 is more technical with its BAs.

For details the FAN 2 is the winner, but not by much. It shows more micro details, still less than SA6 does. As for soundstage I would say the Serial is wider while the FAN 2 has perhaps a deeper presentation. Both are great in my book in the soundstage.


Penon FAN
This is a fairly new IEM for me and much cheaper than the Serial. It's a single 10mm DD driver. This has a more v shaped sound, it still has a good mid presentation that is just not as present as the lows and highs. I personally like to have a V shape sounding IEM to dampen the mids on some genres.

FAN has more sub bass and mid bass than Serial while the bass notes are more refined on the Serial. As for speed they are close to the same.

Mids are more recessed on FAN, both voice and instruments gets shadowed some by the bass and treble. Some small bleed in the lower mid bass, but it is minor.

Going into the upper mids and lower treble the FAN has more energy and is increased over the Serial. The presence region is a make it or break it part of the sound, I prefer some extra bite while some others do not. The Serial is much more safe here.

FAN has an excellent upper treble also well extended. While the treble in the Serial is more pleasant and smoother.

Both imaging and soundstage is a win for the Serial, they are quite differently made and priced so it's not a shock.


Truthear HOLA
A small comparison with the newest entry level hype IEM. Different league. HOLA is less detailed, leaner sounding in both the mids and bass. When looking at measurement of both the difference shouldn't be as different in the bass notes. Still the HOLA is softer and less defined in the low end, and lacks some mid bass thump. Treble extension while good on the HOLA is still less detailed than Serial. For people who prefer a leaner and softer presentation the HOLA is great, especially for the price.



If you read the whole review you might have noticed I do have a love for the Penon Serial. While I can nit-pick and say that I would have liked more microdetail, that would have changed the approach of the sound. It has a pleasant line where it's detailed and relaxed enough to not make music a task to listen to.
It has a safe tuning with enough low end to please most, even some bassheads. The mids are romantic and give a full sound. The highs are slightly relaxed and for most people pleasant and engaging.

I would call it a genre master, I can put my music library on shuffle and enjoy whatever that comes on.

If I were asked to take one IEM with me on a 1 year trip this would have been my choice. I also bet that it is one of the safest sets when someone is asking for a recommendation.

It's not an IEM for the ones who need ultimate resolution and capabilities, but for the music lover.

Going back to the start, this is a bold vintage speaker packed into a small IEM and I truly recommend it.

Last edited:
marcos antônio
marcos antônio
could you tell me if it handles well with heavier genre and full of more complex and faster passages like Death Metal?
Depends, I don't find it to struggle with complex metal. But it's still not a super clear sound, it sounds slower and if you need something super fast and clear ita better with a planar like S12 or a BA iem like Neon Pro.
@marcos antônio
marcos antônio
marcos antônio
I have the Globe and I think it's perfect for listening to Metal it handles these faster and more complex passages very well, but I'm curious to try the Serial but I'm afraid I won't like it as much as the Globe enchants me and I'm in doubt.



100+ Head-Fier
I wonder how the Serial compares to the UM 3DT. I own the 3DT and I really like it. Especially after adding the Tanchjim filters.