Symphonium Audio Crimson

Symphonium Audio is an independent manufacturer based in Singapore, specializing in high-quality in-ear monitors (IEMs). They are known for their innovative designs and advanced technologies, aiming to provide a balanced and natural sound signature. Some of their popular models include the Symphonium Titan, Symphonium Meteor, and Symphonium Helios.



The Symphonium Crimson is a flagship-level in-ear monitor that delivers an engaging sound signature with incredible technical performance, remarkable dynamics, and outstanding resolution. It is versatile and offers an impeccable build.

The Symphonium Crimson is characterized by its reference-like tuning with slight warmth and a focus on dynamic impact, clarity, and precision. Its sound signature is engaging yet natural, achieving the balance between technicality and musicality.

Disclaimer:
This review reflects my personal and subjective listening experience with the mentioned audio gear product. I would like to thank Symphonium Audio and Audio Geek Brotherhood of Audiophiles for organizing this review tour in my country and allowing me to share my thoughts on the product. This review is not influenced in any form and I have not been compensated. Before I start, I would like to mention that most of my impressions of the gear are based on the sources and test tracks mentioned, so your mileage may vary.

Sources: Earmen Angel, Cayin RU7



Specification:



Driver Crossover

TrueX™ Custom 4-Way Crossover with FLAT™ Technology

Frequency Response

10Hz - 24kHz, ± 2 dB

Sensitivity

106dB/Vrms @ 1 kHz

Impedance

6.05 Ohms @ 1 kHz

Socket

Spring Loaded 0.78mm 2-Pin

Cable

26 AWG Pure OCC Copper Litz Novaron
[4-Wire or 8-Wire Option Available]
OE Plug Termination w/4.4mm and 3.5mm plugs

Cable Impedance

0.12 Ohms (3.5mm), 0.12 Ohms (4.4mm) @ 1kHz (8-Wire)
0.20 Ohms (3.5mm), 0.20 Ohms (4.4mm) @ 1kHz (4-Wire)



Build & Design

The Symphonium Crimson impresses right out of the box. The IEMs are constructed with a CNC-milled aluminum shell, giving them a solid, premium feel. The crimson-red color, combined with minimalist design elements, exudes understated elegance. Despite the all-metal build, the IEMs are lightweight and comfortable for prolonged listening sessions The included cable is of excellent quality—supple, tangle-resistant, and free from microphonicsThe stock cable is terminated with 4.4 balanced connectors, allowing the Crimson to pair seamlessly with balanced outputs as it needs power to shine



Preface

Before I start the sound aspect, let me be clear on this, this iem doesn’t sound like an all BA based iem, so if you’re buying with such sound in mind, just give it a listen before buying, it doesn’t sound anything like any of the BA based iems I have listened or reviewed (Supernova, Cantor, Andromeda etc). It sounds like a single DD iem or a hybrid iem with good DD sound characteristics. And the most important aspect more than how it sounds, is the power it requires, 6.05 Ohms and 106dB/Vrms @ 1 kHz tells you that you need to have a very powerful source, Cayin RU7 cannot power it and starts to jitter/fumble/distort at more than 50% volume on high gain so if you have a weak dongle, add an amp. Earmen Angels drives it on high gain successfully and with authority. While I did try it with the Cayin IHA6 and mighty impressed on how it scales, I would like to refrain from including it in the review since I have always believed that iems should be judged based on portable sources only.

Now let’s move to sound.


Bass
The bass on the Crimson is a standout feature. It is deep, authoritative, and textured, yet controlled without any sense of bloat or mid-bass bleed. The sub-bass extension reaches into the lowest octaves, delivering a satisfying rumble that remains clean and articulate. The Angel enhances the Crimson’s bass dynamics, lending it extra weight and slam. While RU7 adds a slightly warmer tone and smoother texture to the bass, particularly in NOS (non-oversampling) mode. Sub-bass remains impactful but takes on a more analog, organic quality, making it perfect for acoustic or jazz tracks.



Midrange
The midrange on the Crimson is natural, lush, and detailed. Instruments and vocals are presented with outstanding clarity and separation, allowing each element to shine without congestion. The midrange comes forward with a crisp, clear presentation. Male and female vocals benefit from a touch of energy, enhancing their presence. With RU7 it is smoother, more organic tone to the midrange. The natural timbre and fluid decay of instruments come alive, creating an emotional and musical presentation.



Treble
Treble performance on the Crimson is refined, detailed, and extended. It avoids harshness or sibilance, maintaining a smooth yet energetic presentation. Cymbals, violins, and high-frequency instruments are crisp, airy, and well-separated, adding sparkle without fatigue. Earmen Angel enhances treble clarity and microdetails, making high frequencies sound precise and transparent. RU7 slightly smooths out the treble, adding a touch of warmth and relaxation. It still retains excellent detail, but the presentation is less aggressive, which makes the Crimson a fatigue-free companion for longer sessions. Technical Performance Soundstage & Imaging The Crimson offers an expansive soundstage that feels holographic and immersive. Instruments are layered and precisely placed within the soundstage, with Earmen Angel, the soundstage gains impressive width and height While the RU7 excels in creating a more three-dimensional soundstage with added depth. The imaging retains its precision, but the RU7’s natural tuning creates an intimate yet immersive experience.

Detail Retrieval



The Crimson excels at resolving fine details without sounding analytical. Microdetails, like string plucks, vocal nuances, or room reverberations, are presented with clarity and finesse. The Angel emphasizes details with its clean, resolving nature, while the RU7 adds a layer of musical smoothness. Dynamics The Crimson delivers outstanding macro and microdynamics. The Angel brings out sharper dynamic contrast, while the RU7 offers a more fluid dynamic range.



Summary

The Symphonium Crimson is an exceptional IEM that combines reference-level clarity with a touch of musical warmth. Its technical prowess—detailed bass, lush mids, refined treble, holographic soundstage, and dynamic range—makes it a standout performer in its class. Whether you are a detail-hungry listener or someone seeking musical immersion, the Symphonium Crimson, paired with the right source, delivers such a sonic experience that justifies its price tag.

As part of Audio Geek tours received the Symphonium Crimson for an extended period of time. The tour serves as a great platform to experience audio gears and I'd like to thank them and Sandeep for the initiative. Sharing my thoughts on the Symphonium Crimson in this write up



Build and Accessories
The Crimson is the current flagship of Symphonium audio. Coming from an already popular brand the Crimson shows a sign of maturity soundwise and build wise. The shells are more ergonomic compared to the Helios and definitely can easily adapt to most people's ears. Metal build with a carbon fibre faceplate and red accent, definitely a looker. The cable is 8 wire Novaron which is supple and has no memory or microphonics. Divinus velvet eartips come in the package and I feel it's best suited for this IEM.



Sound Impressions
It's an all BA iem with 4 drivers and 4 way crossover. Overall a slight U shaped Sound profile with an emphasis towards mid to upper treble from my listening. It can be driven well with a portable source, I used my RS6 and sounded better with additional amplification when I tried with the xduoo pro as an amp. I'd used a warmer source for my preferences as it had great synergy with the slightly bright sound of the Crimson.

The Bass is textured and fast, slightly boosted in the subbass to give a satisfactory impact and heft. Lower mids were subdued for my preferences and sounded a bit lean for my tastes. Upper mids is well done without any shout or aggressiveness. Treble is again boosted a bit which gives a sense of clarity and open sound with excellent details. Slightly aggressive treble though refined which makes it a great choice to decipher the last bit of details you'll miss out on other IEMS.

Dynamics are class leading in the $1500 price range. Imaging is accurate with a good centre image and spaced out well to produce a solid in ear stage. Instruments sound well separated without being disjoint or panned unnaturally. The boosted treble gives it an extra sense of space and details are forefront making it a well resolving IEM.

Conclusion
Crimson is the best of Symphonium yet, possibly one of the better all-rounder IEM around the $1500 price range. If you're looking for an upgrade to it, in my opinion one has to spend considerably more in the current market. Treble can be a gripe for a few although that's what makes the Crimson a great technical performer. The IEM space moves so fast that many are left in the dust but Crimson is an IEM that can be good even after years, making one neglect the FOMO in the hobby.

Detailed Review of the Symphonium Audio Crimson.

Introduction:
Symphonium Audio is an independent manufacturer specializing in In-Ear Monitors from Singapore. "Crimson" is one of their Flagship IEM.
It has 4 BA drivers
Impedence - 6 ohms
Sensitivity - 84db/mW

Disclaimer:
The Symphonium Audio Crimson that i received is a tour unit organised by " Audio Geek "Brother_Hood of Audiophiles". It is a part of World wide Tour.

Built and Comfort:
Crimson is a medium size iem. It fits perfectly and is very comfortable.The only nit pick is the lack of a vent, which is a disappointing factor as it can lead to pressure buildup during long listening session.

Drivability:
Oh...Boy, Let me tell you straight, Crimson needs a lots of Power to drive. You need a pretty decent and a powerful AMP to make it shine, especially in the Bass region. Without proper Amping you won't get the full potential of the Crimson on every Frequency regions.

Bass:
Crimson has a strong big, bold and authoritative bass. It has got good quality bass, even the quantity is also enormous.The rumble of Crimson is very addictive as well as satisfying. Nonetheless the Midbass isn't lacking. It's punchy and snappy. The bass response of Crimson is tight. Overall I can say the Subbass is boosted. I'm amazed by how an all BA Sets can produced such a good quality bass.

Mids:
Crimson is a very clean and clear sounding iem. It's transparent too. Surprisingly it doesn't have that BA timbre. It has got a balanced sound signature with boosted Subbass. Both male and female vocal sounds pleasing, there isn't any harshness or shoutyness. The instrument sounds clean and crisp. It even slams harder. [ When I try "Holy Diver" by Dio, the kick drum sounds phenomenal, the snare drum slams hard and even the Toms sounds very demanding.]

Treble:
It has got an excellent Treble extension, yet its somewhat smooth and very resolving. There isn't any harshness or sibilance on any of the treble region. It has got the ability to reveal all the Micro and Macro details.

Technical Aspects:
* Soundstage is very wide and Airy. I won't call it a 3D or Holographic type of soundstage but its very near to it.
* Imaging is quite good. In some orchestral track the placement of instruments can easily be detected.
* Layering: Due to its wider soundstage, the instrument seperation is pretty good, can easily feel the depth and distance between each instruments.
* Resolution: This is the best part of Crimson, the details and resolution is fantastic, really amazed by its detail retrieval capability. [ But one thing is clear that It needs some Tips rolling to get all those details and resolution. I tried some eartips like Divinus Velvet, Tang Sancai, Penon Liqueur Black. None of them gave me the satisfaction. So i choose my Final Type E and Voila.....everything became crystal clear.]

Conclusion:
The Symphonium Audio Crimson is a balanced, Subbass boosted Iem, with excellent details and resolution.It has got all the qualities of a Flagship level iem.