Ultra Budget IEM Unlike No Others

After a notable hiatus, Cozoy, a brand previously mostly known for its audio dongle DACs, has made its debut in the IEM market with the Cozoy D1. Priced at a pocket friendly 30USD or RM120, the D1 which stands for “Dynamic 1” enters an increasingly competitive ultra-budget segment. The D1 is also marketed as a competent gaming IEM and features a beryllium-plated dynamic driver, housed in a medical grade resin shell, paired with a quality OCC cable, a combination rarely, if not never seen at this price point. As the company’s first foray into in-ear monitors, the D1 raises an intriguing question: in a crowded and cutthroat market, can it stand out? We’re about to find out.

We’d like to thank Starspicker Malaysia for providing a sample of the Cozoy D1 for us to review and do head to their store for a wide plethora of audio related stuff to enjoy. As always, we are not affiliated with Cozoy, have received no monetary compensation, and our assessment will reflect our honest, opinionated perspective.

Functions & Specifications

Before we start the review, here are the specifications of the Cozoy D1;

• Driver: 10mm Graphene Diaphragm Dual-Magnetic Circuit Dual-Cavity Dynamic
• Impedance: 32 Ohm
• Sensitivity: 100dB/Vrms (@1kHz)
• Frequency Response: 10Hz-50kHz
• Effective Frequency Response: 20Hz-20kHz
• Earphone Connector: 0.78mm 2-pin
• Cable Material: Single crystal copper silver-plated cable Plug: 3.5mm
• Medical-Grade Resin Panel
• 3D Printed Cavity
• 0.78 2-Pin Replaceable Cable Design
• Single-Crystal Copper Silver-Plated Cable

The Cozoy D1 can be purchased through Starspicker or Cozoy website and any other platform such as Shopee or just take a visit to their physical store.

COZOY D1 IEM

Packaging & Accessories

Nothing much can be expected at this price range but Cozoy has been generous here with their packaging and accessories. The box is a straight forward black theme here is medium size with a professional style and a decent design.

• 1x D1 IEM
• 1x Detachable Premium Cable
• 6x Eartips (3 pairs large bore, 3 pairs small bore)
• 2x Double Flange Eartips
• 1x Foam Eartips
• 1x Owner’s Manual

The cable is beautiful in purple and feels well made with metal parts, something I have never come across in this price range. No case is included but understandable for this price point.

Design

The design here is the usual CIEM, 3D printed medical grade resin style with blue faceplates and the brand on it in metal. The whole theme here is simple but is quite premium to my eyes and the build here is great with decent polishing. They are lightweight and have a medium sized shell that has an ergonomic fit.

Driving the D1 is a 10mm graphene diaphragm dynamic driver with dual cavity and dual magnetic circuit. The cavity is 3D printed to maximize the dynamic driver performance.

The nozzle here has a width of 6mm at the tip and they are fitted with a steel mesh protecting them against dust and moisture. The nozzle is made from aluminium alloy and has a decent length making eartips rolling easy.

There are only 1 pinhole vent situated near the 0.78mm connector where it is fitted with some dust protector in blue and red corresponding to left and right. The D1 is a very well vented pair of IEM that doesn’t possess any flex and they have a decent isolation without any pressure build up issues.

The 0.78mm connectors are the standard flush 2 pin 0.78mm.

The cable included is a purple coloured, silver plated Ohno continuous casting copper in 4 cores and they are only available in 3.5mm termination. The cable looks great and the sleeve is made from PVC making them soft and pliable. They are a little on the thinner side but that makes the cable practical. A generous inclusion from Cozoy at this price point.

Gears Used for Comparisons

Songs list

Tone and Presentation

The tone of the Cozoy D1 has a warm, mild U shaped sound as they do have boosted lows and a minor lift in their highs with rather flat mids that doesn’t feel recessed or overpowered. Tonal balance here is great without being too bright nor too dark but more on the latter. The overall details here is actually great with a clean and clear overall sound that has decent technicalities. The sound presentation is smooth, inoffensive yet packed with adequate energy with good accuracy, suiting even audiophiles alike. Dynamic range is mediocre with mild extension on lows and high that has some air present but still well worthy of their asking price. The tuning here is more towards a fun, energetic and thick sound which suits casual listeners more than critical ones.

Soundstage

The soundstage here is wide and expansive with a good height to them with a good amount of headroom that is free of any boxiness effect issues. They are slightly tilting towards a diffused field sound that projects the sound in an open but not overly done and they manage to sound intimate with some space in between that gives a perceived large soundstage. In terms of accuracy, the D1 has a holographic soundstage that has accurate spatial positioning making them a suitable pair for gaming and music genres such as orchestral or live music. Immersion here is really good too, making them suitable even for movies as well.

Separation and Timbre

Separation is great with a decent stereo separation that is wide and has no crosstalk issue even and scales up well with a 4.4mm balanced setup. As typical of a single dynamic driver doing the job, there isn’t any cohesion problem and the sound produced is full and gapless. Timbre here is organic, warm, rich and smooth with superb natural sound reproduction, giving a highly musical sound experience that is enjoyable that doesn’t sacrifice sound quality.

Drivability

Rated at 32 ohms with a 100 db sensitivity, they are easily driven by any source, providing ample loudness even on basic dongles. Scalability here is average but with better sources and bigger driving power, improvements like better extension with extra dynamism are there but rather minor. Their rather low sensitivity actually does not pick up and hiss easily and while having some revealing sound, these aren’t their strength. They are not a picky type of IEM but a well mastered track and also high bitrates track will give a cleaner, clearer overall sound only in a small margin.

The Bass (Low)

The bass here is north of being neutral with a mild boost in the mid-bass, possessing a dynamic bass that has the authority and even though the amount here is high, they are still able to be in control without overpowering issues or bloat but there is some bass bleeding into the lower mids with certain bassy tracks. The slam here has a mild tightness to them with a good pace that has the ability to keep up with busy tracks like EDM with ease. .Details and clarity here is great with a clear bass slam that has decent texture showing layers of bass notes clearly. The bass here is not for purists, instead suit those who want authority in the bass department or better known as bassheads. The bass has great extension with a slow roll off that has a lingering bass effect making the bass sounds bigger and airier. The sub-bass amount matches well with the mid-bass with a great rumble with adequate depth and a clean decay making the overall low region full and impactful.

 The Mids

Midrange is warm and velvety with an almost flat signature that doesn’t have major peaks on the whole midrange. The details and clarity here is up to the mark and focuses mostly on the macro region with average micro details retrieval. The mids here have a good amount of body that has some thickness to them that makes them sound rich. There is some coloration present here and they have a vivid sound that resolves well but transparency here is mediocre as there is some unnatural colour being added albeit minor. The transition well from the lower midrange with a mild climb towards the upper mids producing a lively sound with some brilliance added to them giving a livelier vocals especially female vocals. Male vocals sound deep and soulful but with certain warm sources, they tend to sound too thick. Instruments perform mostly well like drums, bass and percussions but not so much for strings.

The Highs

The high here is slightly north of neutral with a mild lift on the 10 kHz region and beyond that contributes to their overall bright-ish sound. The high range here packs a good amount of energy with a piercy sound that manages to sound mostly inoffensively smooth although borderlining sibilance. Sparkle here is great with a clean and clean decay that is energetically lively. Details here are superb as every high nuance is well displayed while also possessing a good amount of clarity. The pace is fairly quick and they have a decent extension with a mild slow roll off that gives the highs some air. Treble has a dose of intensity added to them that contributes to the overall clarity on these D1 and also having an energetic high range. The high range here doesn’t really suit those who are treble sensitive as the highs are a tad aggressive. High range timbre here is accurate without any major unnatural sound but they are a little sharp on the edges.

Comparisons

VS Sivga SM100

One of the latest releases from Sivga, the SM100 although positioned as a gaming IEM, they have a rather pure sound signature with a neutral presentation with a clean and clear overall sound that punches above their asking price. It does cost more than the D1 at 40USD but the D1 has a better braided cable which slightly makes them a better value.

High range is stronger on the D1 with a more sparkly sound but both are crisp. Highs on the SM100 are smoother and more refined while having the same details and clarity. Treble on the D1 has a touch more intensity while the SM100 has a more accurate treble.

The midrange on the D1 sounded fuller and thicker with a more vivid, coloured sound while the SM100 has better details with a more accurate midrange. Transparency on the SM100 is better with nearly no coloration present. Vocals on the D1 have better intimacy while the SM100 is livelier.

Bass quantity on the D1 is bigger with more mid-bass and sub-bass amount. They are also deeper but accuracy falls on the SM100 and they are more neutral as well as more accurate.

The soundstage on the D1 is slightly bigger than the SM100 with a similar amount of air.

Verdict: SM100 does have a more refined overall sound that has better neutrality but the D1 sounds bolder with better bass presence and immersion.

VS TangZu WanEr 2025

The latest edition of the highly rated, ultra budget IEM from TangZu and they do cost slightly less than the D1 but the D1 certainly has the better build with its 3D printed medical grade resin. Both are driven by a single dynamic driver and the WanEr do give a more neutral balanced approach but lack excitement like on the D1. Cable on the D1 does look prettier and feels more robust but the WanEr has the 4.4mm balanced option.

Highs on the D1 do sound a little brighter and crisper with an extra air. Sparkle on D1 is livelier and crisper with slightly more air while the WanEr highs sound more natural. Details on both are similar but clarity is slightly better on the D1 due to the extra treble amount.

The midrange of the WanEr does sound more accurate with less coloration and has better transparency while the D1 has a more thickish mids that has better intimacy. Details are better on the WanEr with better clarity and resolution. The upper mids on the D1 is more apparent and has bigger brilliance.

Bass amount is on the D1 side with their boosted bass while the WanEr has a neutral flat bass that sounds more accurate but with less impact and energy. Details are similar but the WanEr does have better clarity with no bleed present on any source.

The soundstage on the D1 does sound wider and a tad airer.

Verdict – Both are playing on the same plane of decent performance with the WanEr having a neutral accurate sound while the D1 with their V shaped sound that is way more exciting. The build and value certainly has to go to the D1.

Synergy

The V shaped sound of the D1 does require a good matching as some bassy source may exacerbate the bass bleed and some bright source will incur fatigue. Sources like Cirrus Logic Sabre and AKM do go well providing a thick, intimate presentation that is very enjoyable. Scalability is average so not much power is needed making them a suitable pair for everyday usage.

Good synergy

FiiO BTR7, Hidizs S8 Pro, Questyle M15, Time Ear BTE9 , Qudelix T71, EPZ TP30, FiiO Q7, EPZ TP30

Not so good synergy

FiiO Q15, EPZ TP35, Hiby FC6, Cayin RU7

Who Is It For?

Suitable for – Instrumentals, rock, metal, ACG, EDM, hip-hop, casual listening, gaming, movies, beginner audiophiles

Not really suitable – acoustics, classicals, monitoring

Final words

The ultra-budget throne has been a coveted seat for staple brands with proven tuning experience, yet Cozoy has surprisingly secured a spot for itself and even leads in build quality. At a mere 30USD, its 3D-printed medical-grade resin shell is rare, if not unprecedented, in this price range. Its sound is no slouch either, offering a well-tuned V shaped signature that is energetic, fun, and immersive, without sacrificing technical performance. While it may fall slightly behind neutral tuned IEMs in certain regards, the Cozoy D1 remains a unique product that caters to a wide audience, from gamers to audiophiles. It is certainly worth a try.

I would rate this product a 4 and half over 5 stars.

Pros

• Great build with a nice design and great fit
• Well tuned V shaped sound
• Rich, organic timbre
• Wide soundstage with good air
• Thick, warm, vivid
• Decent overall details and clarity
• Meaty, authoritative bass with deep, rumbly sub-bass
• Good resolution
• Sparkly, crisp high range
• Intense, extended treble
• Value

Cons

• Lack transparency (nit-pick)
• Not for monitoring or clinical listeners
• Midrange slightly recessed (nit-pick)
• Mild coloured midrange
• Bass bleed on bassy sources