Cozoy D1 Review 

Intro 

This review and feature covers the latest from the audio brand Cozoy named the Cozoy D1 $31. This review is a bit late to the party but that is actually how I like it. I don’t need to be 1st in line to the hype train. I was approached a while ago to review this set and shipping issues derailed my chances early on. Again, I prefer that. I like to review when the dust settles. At any rate, the Cozoy D1 is a single dynamic driver earphone sporting a graphene diaphragm and a dope design for an ultra-budget iem. I’ve actually had the D1 in my possession for a little over a month and have had plenty of time with the D1 in my ears to fully provide my thoughts to you. Can I just tell you, this set is certainly very solid for its cost. Let’s just get that out of the way, no guessing, the D1 is a very nicely priced single DD and should absolutely not be slept on. 

Cozoy

I’ve seen a few Cozoy products over the years, but from what I can gather this is not a huge brand out East. They’ve had some success, but this is the first Cozoy product that I’ve had the pleasure of listening to. I was kind of amazed to see that Cozoy has actually been around since 2014! That threw me for a loop. Friends, you only make it 12 years in this business if you are good, make solid decisions, and if your products do the talking. Nobody can fake it for too long in this market unless they lie through their teeth and mass produce, flooding the market. That is obviously not Cozoy. Also, after hearing the D1 I can at least say that they make a solid budget range single DD. That’s for sure. 

Competition 

It should go without saying that the Cozoy D1 has a huge swath of competition surrounding it. In fact, I have the Dunu Titan X coming up for review right now. Shoot, I just reviewed an absolute BALLER of an iem in the Kefine Klean SV, and let’s not forget the Kefine Klean original. When there are sets like the EPZ Q1 Pro, the KZ Zenith, Truthear X-Crinacle Zero, the Simgot EW200, and of course the awesome IvipQ IQ-14 then you’ll have a price segment that is very difficult to choose from for the consumer. Just so you are aware, I could’ve kept listing iems in the $25-50 range for quite some time. I’ve reviewed a mountain of them and so have my partners at MBA. The point being that it’s very difficult for any set to achieve true success in this range unless they are actually very solid for the cost, subjectively, to numerous people who have money to spend. Every set in this range has to really bring something to the table which screams price-to-performance. Let me whisper something to you… “Pssss… The D1 has all the makings of a budget price-to-performance top shelf iem”. Anyways, I am very eager to take this set through its paces and really stress these drivers, compare and contrast with other sets and just get to know the D1 backwards and forwards. I do that so that nobody can say I didn’t tell you everything I know and if you know me, I will exhaust every last bit of digital ink to do so. So, with that said, I am very much ready to dive deep on this one. Who’s coming with me? Now, without further ado, the Cozoy D1… 

Non-Affiliated Purchasing Links:

–Cozoy

Gear used for testing 

–Shanling UP6

–Shanling UA6 

–Ifi Go Blu

–BASN PA60

–Surfans X10 

–Hidizs S9 Pro Plus  

–Shanling UA7

–Shanling H0

–Hidizs AP80 Pro Max 

–Fiio JM21 

–Hiby R3 Pro II

–Hiby R6 Pro II 2025 

–Shanling M1 Plus

–IBasso DX240 with Amp8 MK2 

–Shanling M6 Ultra 

–Fiio Q15

-Many more sources used including weaker Android 3.5 set phones, iPad, and a few weaker 3.5 se dongles

Packaging / Accessories 

Unboxing 

The Cozoy D1 arrived at my home in a rather small rectangular black box sporting a black sleeve which has “Cozoy” imprinted in the middle. On the back you’ll see some specs as well as a company graph of the D1. On the sides are some nicely worded mission statement style sentences from Cozoy. Take off the sleeve and you’ll see the actual black box which looks identical to the sleeve. Take off the box top and the first thing you’ll see will be the gorgeous D1 iems with the cable attached while sitting in foam cut-outs. Next to the foam you’ll. Notice a small cardboard box tucked tight. Inside of that box you’ll find the eartips. That’s about it. Nothing grand or over the top. As one would expect. 

Eartips

Within the packaging Cozoy supplies a total of 7 pairs of eartips over three different styles of tips. The first style of tips are a sole pair of simple slow-rise foam eartips, large size. I really do not like foamies and so I didn’t even try them. Sorry, I typically go through everything for you but foams usually detail bass and attenuated the highs a stitch too much for me. At least that’s how they always work in my ears unless they have a very hard and rigid stem. These do not. The next set of three (S, M, L) tips are a triple-flange white silicone set with a medium firm flange which really aren’t terrible at all, but I do not feel that they work as well to bring out the best in the D1. Lastly, Cozoy added in three pairs (S, M, L) of white silicone eartips with a narrow size bore and are oddly small. These actually look like true wireless eartips. Really a strange addition into the package. Again, oddly small. I’d even go so far as to say that the large size is equivalent to any other type of tips medium/small size. So very small. I actually went through a few different styles of 3rd party tips and found the KBear 07 eartips to be the best for sound and comfort. Mostly comfort. Also, a semi-wide bore size only helps this set. 

Cable

One of the cooler additions into the packaging is the cable which comes attached to the D1 upon opening its box. Friends, this cable is very cool looking and much better than any cable that you’ll usually find with $25 to $30 iems. To be exact it is a beautifully striking purple colored cable, 2-pin, and terminates in a 3.5 single ended jack and it has a very nice braid. This cable is made out of 4-cores (216 strands) of single crystal Cooper and plated in silver (SPC). Really a very nice cable. I was very surprised to see it and it contrasts the D1’s color very well. Truly gorgeous in appearance. To add to that, the cable is very pliable, skinny and soft enough too which is easy to handle and roll up for storage and it isn’t at all microphonic. Having said all of that, most of my critical listening was accomplished using a 4.4 balanced cable. I actually cable swapped to the white 4.4 balanced Nicehck SnowAG. The color matches well and this cable really does pair well sonically. Of course, its price is as much as the D1, but it simply pairs so well. Obviously, for any single ended listening I was happy to attach the included cable. Truly a smart choice to go with that electric purple as the aesthetics are out of this world.

Build / Aesthetic / Internals / Fit 

Build Quality 

The market as a whole has many well-made budget sets, and the Cozoy D1 is absolutely one of them. Made almost entirely out of medical grade 3D printed resin and very well put together in a seemingly seamless fashion without a rough edge to be found. I see no misalignment, no glue, nothing. Oddly enough, this set does not look cheap at all. I also notice that the nozzles are actually made out of a shiny silver alloy (likely aluminum). Each nozzle is about medium length (average) with about 6 mm nozzle widths. One of the best qualities of the build is how comfortable this set is. Much of that has to do with the very ergonomic shape, nozzle angle, form fitting shells, and the D1 are a very lightweight iem. Perfect for long listening sessions. Honestly, for $30 I have zero complaints. Furthermore, I don’t think anyone else can truly complain, Cozoy did a nice job. 

Aesthetic 

This is one of the absolute best qualities of the D1 because this set is very nice looking. I mean, folks, this set is very nicely designed as the main shell body is made of black resin while the faceplates have this blue/electric purple colorway which is very striking in my opinion. You’ll also notice some black streaks running down the faceplates which add a slick looking contrast to the purple. On the center of the faceplates is “Cozoy” imprinted in slim white lettering which looks nicely sized and doesn’t appear gaudy or odd. I just love the look of this set and literally everyone who sees them instantly asks what they are. Cozoy didn’t make some crazy ornate design aesthetic, and they didn’t go over the top at all. Just a perfectly minimalist look. Cozoy really nailed the aesthetic appearance of this set. 

Internals

Now, at the heart of the Cozoy D1 is a 10mm single dynamic driver with a Graphene diaphragm and a very well thought out acoustic architecture for a $30 iem. Almost above and beyond, if you ask me. Graphene is a wonderful material to use in iems and at one point it was some of the best driver material on the market, period. In fact, I think the market went away from graphene far too quickly and we should see more brands bringing it back. Graphene typically is very fast, with clean-lined transients, and a relatively natural tone if tuned well. It is extremely stiff, very lightweight and can become very thin too. Now, Cozoy went with a dual-magnet structure inside of the D1 instead of one magnet like so many budget sets. Also, Cozoy had the presence of mind to give this set a dual cavity design which basically means that the driver is situated between two different chambers and air volumes. Each cavity works together to control stuff like air pressure, standing waves, and any wild resonances. There isn’t much more than that but I can assure you that you won’t see a 10mm Graphene DD, dual magnets, and dual cavity often at this cost. 

Fit /Comfort

I’ve already alluded to my experience with this set when it comes to comfort. The D1 is exceptionally comfortable for me. Literally, it feels like this set forms my ears almost perfectly once I get my eartips correct and a good seal the D1 fits me like a charm. Now, I don’t have a clue how they’ll fit you, but I assume thelyy fit most people without issues. 

Drivability / Pairings

Sensitivity 

The Cozoy D1 is rated at 32 ohms and a sensitivity of 100 db’s providing a fairly sensitive iem. There’s no doubt that Cozoy knows who their audience is at this cost and surely they made this set to be able to sound very nice off of even a simple smartphone. Of course, as always, I did my due-diligence and tested the D1 with exactly that, my old Android smartphones. I also tested on my iPad, weak 3.5 single ended Conexant dac dongle dacs. Honestly, this set plays well off of everything that I tried. Truly, I do not feel that you “need” anything more than a smartphone for this set. However, that doesn’t mean that the Cozoy D1 won’t scale up in sound quality to some degree with more powerful and cleaner/better sources. 

Output Power 

There is definitely a cap on how much juice you give this set. Not that I heard any audible distortions or anything, but the sound simply caps on how much better the D1 sounds due to power output. In truth, I find that a solid dongle dac will suffice. I’m talking about products like the Shanling UA6, EPZ TP35 Pro, Shanling UA7, Hidizs S9 Pro Plus, etc. Anything with ample power output, a 4.4 balanced port (not needed but helps) will be more than enough. I used this set with just about every 1-watt dap that I own, and I didn’t hear any true improvement due to power when I used them. The true improvement comes with how you pair this set tonally, and how clean and quality the source you have is. 

Source Pairing 

Now, I find that the D1 is definitely at least “somewhat” source sensitive. No doubt that D1 has a very energetic sound, vibrant, speedy, the D1 is almost dead neutral in tonal coloration, but it’s also a very lively and zestful sound. Alot of sparkly vivacious moments with this set. So, without question I cannot go with any source nearing neutral/bright. It’s simply too much edginess, too much grain, too much kinetic pizzaz for a brighter source. Actually, I find that warm/neutral sources tend to be the best. For a few reasons, but mainly because a warm/neutral source won’t derail what makes this set special and kill its fine-lined cleanliness. However, a warm/neutral source will also add just a smidgen of warmth throughout which kind of brings that energy down a tad. To take it even further, try to find a dac/amp or source which tends to have a smoother cadence. I’m telling you all right now the D1 will sound like it should cost twice as much. Sources make a huge difference with this set in my opinion. The Shanling M6 Ultra is absolute heaven with this set. Or the Shanling UA7 in tube mode is another. The smoothness does not smoothen the finer acute details, but it does soften the grain, and it does provide a more refined sound. 

Sound Impressions 

*Note: before I take the deep dive into the D1, I first want to let you all know some details of my time with this set. First off, like always (with every review) I gave the D1 some burn-in time. For this set I put them on for 3 full days. Whether you “believe” in it or not… it certainly helps. Just do it and thank me later. I listen mainly to flac or better files (some MP3) which are stored on my devices and rarely do I stream my music. Furthermore, I used KBear 07 eartips for all of my critical listening. I also used the Nicehck SnowAG 4.4 balanced cable for the majority of listening. The Android music player of my choice is mainly UAPP (USB Audio Player Pro), as well as Hiby Music Player (for some daps), and Eddict Player for a few others. 

What’s It Sound Like? 

The Cozoy D1 represents a very solid option at $30. I’ll just say it so that there’s no confusion. I’m reviewing this set and so you already know that I like the D1. Cozoy did a solid job. Now, whether the D1 is good for you and fits your sonic preferences is an entirely different question. To my ears the D1 comes across almost neutral with hints of seasoning, not flat neutral. Let me explain. So, flat neutral will be just that… flat. No dips, no hills, no real coloration, and basically without any extra flavor. The D1 has quite a bit of flavor, yet subtly feathered-in to an otherwise neutral sound. Like, the D1 has this moderate bass emphasis. Not enough to change the overarching hue of the soundscape, but rather the type which shows its breadth when a track calls for it. The kind which will surprise you with its depth when the moment fits. Also, there is certainly an upper mid boost followed by a sparkly treble and so the D1 most definitely has a lustrous and airy quality to it. I plainly hear some very nicely controlled dynamic vibrance and macro-dynamic accentuation with touches of nice tonal contrast for only $30. So the D1 certainly has some flavor. It has some moxy, some gusto, and some real controlled intensity which can be very enthralling.

Signature 

Now as far as sound signature is concerned the D1 comes across as slightly V-shaped with a subtle U-shaped lean and almost perfectly follows the 2019 Harman Curve… by looking at the frequency graph. So, certainly Harman inspired, but also a well-done version of a Harman sound. Honestly, this set is extremely well balanced dynamically, across the mix, without any real dominance from any region. If I were to say anything, I’d tell you that there is an upper mid “mild” focus, but nothing which forces its will spectrum wide. Assuredly in actual real world listening, I don’t hear a classic V-shaped sound, it isn’t what I’d call straight U-shaped either, and not quite W-shaped to my ears. Perhaps the energy and forward upper mids of a W-shaped set, but not quite. This is what you get when the emphasis of each region is so dialed-in as the bass, mids, and treble really don’t fight for influence. Every region coexists very well. Now, the mids aren’t recessed in any manner which is obviously noticeable. Perhaps the lower midrange has a slight recession, but I’ll get to that later. The D1 has good presence EVERYWHERE, the bass region has a nice balanced lift, the mids have that clean controlled vibrance and intimate appeal, and the treble has plenty of shimmer and sparkle. 

Timbre 

In my opinion the D1 has some nice timbre too. Not perfectly natural, more like natural-lively. Again, the D1 has that very expressive and energetic sound, tighter transient behavior too and so the sound is not what I’d call “organic” or “earthy”. A bit too zesty up top to call it that. This is the type of sound which may bite you from time to time in the upper mids, yet “generally” that sort of glare is kept to a minimum. By the way, if you can find a warmer source, you’ll be surprised how well the D1 adapts to it and the timbre will veer more towards that organic feel. Though nothing kills the spirited and enthusiastic luminous glow to this set. Really great for a $30 budget range iem. I cannot say that enough. Still, there are so many tracks which are very gripping with the D1 in my ears. A nice enough stage, full sounding, semi-wide, great height, with adequate depth, extremely clean-lined and technically proficient as well. There really isn’t a whole lot of genres which flat-out won’t work with this set either. I’d go so far as to say that it’s very close to an all-rounder style minus a few genres more dependent on a deeper and more bulbous bass section. The musical/analytical spilt is around 40/60 to my ears as it leans analytically based yet with a melodic spirit. Basically, musicality isn’t lost on the D1 at all. It isn’t all clinical and while the timbre has some dryness, it isn’t papery or devoid of moistness either. Just a very nice balance which promotes some fluidity whilst also having very capable detail retrieval. Cozoy did a solid job. 

Bass Region 

The bass region can bring some slam folks. The type of slam which shows up when called upon and can surprise you with its punchy and dense nature. Without question the D1 is NOT a basshead iem. Bass-bois might as well keep looking because the D1’s bass is wholly predicated on note definition and cleanliness measured against just enough hearty slam to invoke a full-bodied kick drum. Enough weight and guttural meat for bass guitars. However, once again, there’s no doubt that this bass prioritizes cleanliness, note definition, and note control. You’d be surprised that the bass isn’t sloppy either as the D1’s low-end can take on fairly complex bass passages well. I’d definitely call this a sub-forward bass with a clear sublevel emphasis yet without losing the heart of the mid-bass. If anything, I’d say it has a moderate lift with a bass shelf peaking at around 9 dB’s, nicely measured against an upper treble pinna gain peaking at about 10 dB’s. Once again, it’s all about dynamic balance. It’s restrained in the spirit of balance but boosted enough to have some fun too. 

Sub-Bass 

As I said, the sub-bass is the dominant portion of the low-end with a clear sub-bass focus. The kind of sublevel weight to come across foundational, grounding, and mildly authoritative. I hear a harder lined, hard edged style note attack with cleaner leading edges and without anything which I’d call soft or plush, generally. I would have to say that the sub-bass leans quality-over-quantity with good space between notes. You won’t hear the D1’s sublevel response bloating, mudding, or smearing. However, this set can also reach pretty deep too along with a decent haptic feedback on many tracks. I don’t really hear any true masking of any other area of the mix, and the sub-bass follows the theme of this set very well. That is, balance, balance, balance. Listening to “Got Your Back” by Washed Out is a perfect example of the D1’s ability to express clean note articulation along with a beefy and textured rumble that sounds much more present and palpable than obesely-physical. No swelled moments of bassline judder but enough convexity and vibratory feedback to let you know it’s there. 

Mid-Bass 

To me the mid-bass is very clean with only a touch of bass bleed adding an ever-so-slight amount of warmth into the mids. Definitely a quicker and tidier presentation that is all about control of the region. Also, this is the one area which rises to the occasion the best and doesn’t really affect the rest of the mix when it isn’t called upon. Nothing even remotely sloppy, not soft, nothing pillowy, and there’s not a chance for anything one-noted. For a $30 single DD Cozoy tuned this set to be able to take on faster and more complex arrangements very well. However, the mid-bass is not going to attract anyone who values a girthy bass. I hear a very distinct note delivery, tight transients, nice snap, some crispness, moderate density, with a quick punch and appropriately doled-out mild-mannered dynamism. So put those descriptors all together and you will likely have an idea what I’m trying to describe. Basically, the mid-bass plays alongside the sublevels very well with a nice level of resolution for the cost. 

Downsides to the Bass Region 

The biggest gripe about the low-end will undoubtedly be the less focused and authoritative nature of it. Again, bassheads shouldn’t even consider this set. What makes this bass region so wonderful for the cost is its clean-lined manner and balance with just enough weight and power to represent this region for many genres. But it won’t be that fun or guilty pleasure style for anyone. Beyond emphasis, the bass is fantastic. At $30 you’d be hard-pressed to find a bass that is head and shoulders above the D1 in sheer quality. Granted, there are plenty of great bass displays from other sets. I just find that the D1 has the technical aspect of the bass sewn up in a manner that many more expensive iems cannot match. It’s all about the tuning folks. One thing a Harman sound is good at is a cleaner bass that is still fun enough, and if done right it’ll prize clarity over boom with a fast twitch reflex and a punchy feel. Not bad at all. 

Midrange

The theme persists within the midrange which leans analytical over musical without losing engagement. It’s a fine line to walk, especially for a set costing so little. However, it won’t be for everyone. Anyone who desires a lusher and warmer, or earthy experience may want to keep looking. On lesser energized tracks the D1 comes across close to natural, more organic. Though on more spicy tracks you’ll have some subtle glare, some metallic tinge at the crest of notes as well. So, you have to know what you are getting. On the plus side, the D1 has great resolution, clarity rich, fairly crystalline, with plenty of air and levity and totally dynamic with very expressive and vivid macro-dynamics. Again, this midrange has quite a bit of energy and vigorous flare providing a fun sound (in that regard) without losing all emotionality. Separation is a strong suit, details are easy to track in most songs, intelligibility is very high, with better imaging capabilities than I would’ve thought. I should also add that there is some warmth catering more towards the lower midrange and the mids as a whole come across more forward, with fantastic presence which makes vocals quite nice. I hear nice crispness, great snap on percussions, edge detail on strings, and a note weight which comes across leaner but also compacted and not overly dry. 

Lower-Midrange 

The lower midrange is the only area I’d say that has a very subtle recession. I really have to train my ears towards this region to hear it though. I say that because this area also has some touches of warmth, but certainly not what I’d call rich, lush, or full-bodied. More like lean-natural with solid enough note density, very good clarity, and a fairly precise sound. I definitely prefer some added warmth (personally), yet I’ve managed to enjoy the D1’s low-mids and enjoy the style of tuning. Now if you are seeking out a lusher experience with a thicker note body then the D1 will likely disappoint to some extent. Some instruments will sound leaner and less authentic because of this. I want to get that across. On the flipside, if you desire a detailed sound, good note definition, and glass lined notes which don’t sound fuzzy, masked, vague, or distant, but rather sound embossed in their clarity and tuneful despite the lack of richness, then the D1 may be for you. 

Male Vocalists 

Now, as far as Male vocalists on the D1, some will come across very-very well, and others won’t sound quite as natural, but nothing sounds blatantly artificial or “off” timbrally. Baritones typically come across well which sort of goes against what I’d assume. However, males who sound naturally deep and centered sound great. Cleaner tenors with a smooth inflection also come across very melodic. Think clear baritones which aren’t very chesty or gruff, like Avi Kaplan in “First Place I Go” or tenors such as Ed Sheeran in “Perfect” each are examples of males which come across absolutely lovely. Obviously, there are many more which work very well. If there was a weak spot in this set it would likely be the low-mids and if that is the worst thing then I feel that the D1 is doing very well. Especially at such a low cost for such a well-rounded iem. 

Upper-Midrange 

Let’s take a look at the upper-mids now. So, the upper midrange has a more pronounced and in my opinion is one of the best pieces to the D1 puzzle. Very melodic even with its more energetic and lively sound. I really like that Cozoy tuned the upper midrange to take me right to the brink of shout, stopping just short of discomfort, and sound much more like awesome presence than pinna pain. For me, the upper midrange is where the D1 shines the brightest. All instruments come forward, somewhat intimate, yet vibrant, sprightly, tight transients, crisp leading edges, natural-to-tight decay, and a nice bright/neutral airiness that comes across well controlled. You’ll hear a touch of vibrant edge-grain on very rambunctious recordings (this set costs $30), but for the most part the note control is fantastic for an ultra-budget iem. Pick any female vocalist and she’ll sound very expressive, lively, with a more immediate feel. Singers like Olivia Rodrigo in “Driver’s License” is one which takes advantage of the airy and natural hue of the D1 as her voice is so flowery with radiant inflections. Or Norah Jones in “Come Away With Me”. Her voice sounds amazing on any set, but I like the energy of the D1 paired with the relaxed velvet of her voice. She sounds delectable. Actually, females in general sound delectable. Truly. 

Downsides to the Midrange 

In my opinion the biggest gripe I have with the midrange would be that it is not the richest and enveloping in a smooth musicality sense. The D1’s midrange doesn’t have that liquid cadent fluidity and ultra groovy style tuning full of carried-over bass warmth and viscous mellifluousness. However, do not take those words the wrong way. I am absolutely not saying that the D1 lacks musicality. It certainly does have its own brand of Harmanesque style tunefulness. Cozoy tuned this set to be more than flow, tone, rhythmicity, and emotion. This set revels in its keen ability to resolve subtle details, present the sound field cleanly, well separated, and the D1 was tuned to represent many genres very well. So, I could most definitely see some folks who only go for warm, smooth, and fluid not quite enjoying this set. Good thing for those people that there are plenty of sets in the market which can do that. 

Treble Region 

One thing is for sure, the Cozoy D1 isn’t tuned cheaply. A room full of people don’t have enough fingers to count the number of budget sets which come with screaming treble. Folks, there are a handful of iems in the D1’s price point which handle the whole spectrum the way that it can. The treble region is a very clean, very well extended, airy, and a very energetic treble which also doesn’t have the mountainous peaks and shrill timbre as so many sets have. In fact, for as abundant as the D1’s treble is, I haven’t heard much of anything which has made me turn the volume down. You see, this treble is actually pretty smooth too. I expected something edgy, abrasively etched, grainy, and something coarse. I expected full-on forced resolution. The difference between this set and some sets from “other brands” is that it handles micro information very well. It has those subtle reverb trails, not shrill, not too sharp, cymbal crashes have some lean density, some body. The D1 has nothing even close to glassy highs or brittle radiance. No sir. Cozoy did a very nice job ensuring that the treble work to uplift the spectrum without obliterating it. Add some air, some space, and some clean-lined texture for a low cost. 

Emphasis 

As far as emphasis is concerned, the Cozoy D1 follows the Harman line almost to the tee. If I were to call it anything I’d label it as “safe & confident brilliance” with very solid presence and boosted just a tad more forward than the bass region. Very well measured. It has plenty of treble energy to promote treble bite and very solid immediacy on leading edges. Notes have some crispness, and a nice helping of sparkle coming across as mildly glittery with a shimmery presentation. Most of the emphasis revolves around the mid-treble adding that nice, brilliant presence and uplifting vibrance to give stuff like percussion its hard snap, or that silvery quality to violin, the edge, bite, and pick attack of a satisfying electric guitar. Transient edges come through very clearly, well-articulated too helping to resolve details. With all of that said, on brighter and more vivacious tracks the D1 can sound a hair fatiguing for those sensitive, this is a budget iem after all. I can assure you that nothing about this treble sounds dark, rolled-off, or overly warmed. On the flipside, I also don’t think you’ll hear too much over-the-top sharpness either. Furthermore, distortion is actually very low, even at high volumes. Which is rare at this cost. 

Timbre & Technicalities 

Of the sparkly style treble set in the budget range the D1 stands out. Similar to the Simgot EW200, or the EPZ Q1 Pro in how it has that generally clean, subtly crisp, smoothly cadent, and natural timbre. Nothing coloring the sound so much that the entire mix leans out too much, is too luminous, or sounds artificial. Everything is pretty realistic which makes the cost of this set even better.  Beyond the timbre I also find the technical ability of the D1 to be very solid too. First off, the entire presentation feels open due to its solid extension into the upper treble. No doubt this set gains ample height of the stage which aids the D1 in top to bottom layering of sounds. The D1 also has very low distortion coupled with its clean tuning helps cymbal harmonics, percussive tizz, etc. sound easily audible. Also, again, note separation is very solid too. In all truth, the D1 is an above average set when it comes to all things technical. 

Downsides to the Treble Region 

The biggest problem that I feel some folks would have would be for those people who’d much rather have a less rambunctious and less energetic treble. So many of my friends want an even smoother, warmed, or less vibrant sound up top. Many people are very sensitive to treble brightness. Let me just say right now that if this is you then don’t even consider this set. It is a sparkly and very lively region for sure. I’d also say that the D1 will not compete with more expensive sets when it comes to track density or complex mixes. Sure, it is great for the cost, but don’t expect it to distinctly dissect congested music like some more costly iems. 

Technicalities 

Soundstage 

I’ve certainly noticed that the Cozoy D1 has a very nice soundstage. In fact, it is probably one of the key aspects into what makes the D1 sound as good as it does. Certainly, a contributing factor. Really, I hear exceptional stage height for a $30 single DD. Width goes nice and wide due to the extension up top, the air, the open nature of the sound as well as the sublevel depth. As far as stage depth the D1 is admirable for sure. I would not call them class leading but I can definitely say that nothing sounds closed-in or congested. I hear some front to back layering, but nothing that will blow your mind, as expected. The stage is nicely immersive and comes with good dimensionality, though I wouldn’t say it is full-on holographic. Still, very well done for the cost. Certainly, a far cry from many sets in its price point. 

Separation / Imaging 

This set has a very well controlled frequency response. It is a cleaner sounding iem, tighter transients, open, airy, and well resolved with nothing really masking the spectrum on a consistent basis. These descriptors tie right into why the D1 is so good at having perceivably well separated instruments and vocals. I hear clean and clear space between instruments with distinct lines to compacted notes. Imaging is even better. The D1 does a solid job of parsing out the sound field with a clear and unwavering center image, and great panning left to right as instruments are always spread out and positioned well. 

Detail Retrieval 

Another quality feature of this tuning is how well the D1 is able to resolve subtle details. For all the reasons that the D1 is able to cleanly separate and image the sound field are also reasons that the D1 is able to pick out and draw out the subtleties in my music. I find this set to produce those subtle textures, surface texture, and room ambience very well. It isn’t everyday a $30 single dynamic driver earphone is able to display the minutiae in my music while still being considered halfway musical. Again, the D1 isn’t overly dry, and isn’t 100% analytical and clinical. This set has some smoothness, some warmth, some flow to it. I think you’ll be pretty surprised that you’ll hear some details that other sets in its price point won’t be able to resolve with the same confidence as the D1. Unless those sets are tuned specifically for that reason. All things considered, the D1 has believable timbre, nothing egregiously sharp, and it has good control along with a detailed sound which won’t force your mind’s eye to track details the entire time you’re listening, but you certainly could if you wanted to. 

Comparisons 

EPZ Q1 Pro  ($35)

There is no way that I could complete a Cozoy D1 Review without comparing it to (what I consider) one of the best $25 to $40 iems on the market, that being the EPZ Q1 Pro (Q1 Pro Review). What a fine set folks. I actually reviewed the Q1 Pro way back in March of 2024 and it still ranks up there as one the best under $50 iems. In fact, these two sets sound remarkably similar to each other with subtle differences defining each set’s overall tuning. However, I’ll get to that in a minute. Anyways, the EPZ Q1 Pro is also a 10mm single dynamic driver earphone with an LCP diaphragm sitting in a dual cavity and carrying dual magnets. Very similar to the D1. Let’s see if there are some differences… 

Non-Sound Stuff 

To begin, the Q1 Pro and the D1 both have decent enough unboxing experiences. I think the D1 comes with the better cable, more eartips too, though the Q1 Pro has higher quality tips. Also, the Q1 Pro does provide a carrying bag. Both are nice for the cost. Or at least they both have what you’d expect for the cost. As far as build, again, very similar in that both sets use 3D printed resin and are both very handsome, no glue marks, no sloppy fit ups, they look good. The two are also right around the same size, although the D1 is a hair slimmer. I do find that the D1 is the more comfortable set. The Q1 Pro fits me nicely, but the D1 seems more form fitted to my ears. As far as aesthetics, it is kind of difficult to not like both designs. I definitely prefer the look of the D1, but I think each set is stylish with cool coloration. 

Sound Differences 

As honest as I can be, there is very little which separates these two sonically. Both sets have almost perfect Harman graphs and follow each other very closely. Both have that almost dead neutral sound with just a hair of warmth. Also, both sets align themselves a pinch more analytically rather than musically. Very-very nice to the ear for two ultra budget bangers. I do hear a slightly more robust bass depth and sublevel meatiness from the D1 and a hair more note density. However, I’m pulling at straws on that. The midrange of the D1 shows off the timbre accuracy of vocals and instrumentation a touch better as the Q1 Pro can induce some sibilance, and the D1 is a hair less prone to glare in my opinion. Again, these are small differences here folks. I hear a slightly more forward and pronounced upper mids on the D1 yet with better note control. The treble of both sets is very sparkly, well extended with the Q1 Pro sounding a little more radiant, more energetic to a slight degree as well while the D1 is more composed, more measured in its treble emphasis. Technically, both sets are well done. Both carry nice detail retrieval, nice note separation, as well as imaging of the sound field. The D1 has a hair more perceivable depth of field and a slightly wider stage which does add to the experience quite a bit. Both nice sounding sets for the cost. 

Final thoughts on this comparison 

These two iems are very close in many ways. Yeah, there are subtle differences, but in truth the D1 and Q1 Pro are most certainly cut from the same cloth. I happen to like the D1 better, personally, but that is no rebuke on the Q1 Pro at all. It just so happens that I’ve had a ton of time with the D1 and it has been a very easy set to adapt to. At any rate, both are fine iems. Take your pick and either and you can’t lose. 

Genres

One thing is clear about the D1’s tuning, that is it is a very well done balanced-neutral sound with hints of warmth and a sparkly treble. I find that sets which toe these lines of analytically proficient and musical will typically do well in most genres. I find this to be true with the D1 as it is allllmost there. Honestly, give it a few more db’s of bass emphasis and I think that the D1 would’ve been a full-fledged all-rounder at $30. It’s definitely close. Now, I want to get something straight before I briefly speak on “genres”. First off, please hear me, these suggestions about genres are very loose. I hear reviewers try to declare a set good or bad for certain genres all the time and I have to roll my eyes. I say that because for every genre which doesn’t typically sound as good on the D1, I can find many tracks within that genre which sound fantastic. Also, for every genre of music which broadly sounds solid on the D1, I can find plenty in each which totally make me a liar. There are no absolutes in this hobby folks. Everything is subjective, everything is a loose opinion, and this especially applies to genres. So, basically, don’t exactly take my words with a grain of salt but do understand that I barely agree with myself on these… Lol. 

Genres Which Work Better 

First off, I adore almost all Singer-Songwriter stuff on this set or most acoustic stuff too. The vocal clarity, neutral balanced clarity, great separation all aligns with these. Also, anything Rock. Classic Rock, Pop Rock, think Goo Goo Dolls, Incubus, Paramore, and anything Alternative Rock. Folks, Rock is awesome on this set. Very satisfying, very clean. Here’s a gimme genre; Pop Music. Honestly, Pop Music can go in all directions and it’s really a broad ranging tonal landscape as far as music goes, but generally the D1 handles it all very well. Furthermore, Hip-Hop/Rap which doesn’t require that earth shaking bass is flat-out awesome. I mean, old school stuff like Too Short, Bone, Geto Boys, Tupac, Public Enemy, the stuff I grew up on which lyricists and storytelling are paramount sound flat out awesome for $30. This new style Hip-Hop which tells no story and is all about the beat and heavy drops doesn’t do quite as well, more on that in a minute. Actually, EDM sounds good too. I didn’t think it would, but the sublevel extension is deeper than you’d expect sometimes and something about that clean and clear picture that the D1 offers just makes so many tracks sound… good. Oh, a couple more that just popped into my mind from my notes, those are less intensive Metal, and Light Jazz. Very particular there, but you’d be very surprised. 

Not the Best Genres

Okay, so, this is where I want to explain myself a bit because for all intent and purposes the Cozoy D1 is a legit all-rounder iem. It can play darn near every genre very well. However, there are aspects of some genres which may not be as well suited. As I said, Hip-Hop is great, until you need that eyeball rattling bass that a basshead would appeal too. The D1 cannot do that. Or those super heavy EDM sublevel bulbous and juddering moments, the D1 can’t do that. Sure, it gets close, but not quite. Next, very Lush, very complex Orchestral stuff doesn’t suit this set. There are iems that are better suited for this genre of music. Much of my contention comes from the leaner lower midrange when listening to Orchestral stuff. Lastly, I do not like super-HOT masters in Metal or even some Rock too. I love the treble and upper mid control of this set. Cozoy did a great job taking us to the brink of comfort. However, some Metal tracks can be too aggressive. This set does cost $30. We have to be realistic. Some tracks are simply too bright, too sharp, too grainy, and not the best on the D1. Having said all of that, the D1 covers almost everything very well and I am so impressed with this set. There are so many more genres that I didn’t cover here but I hope you have at least a good understanding of my thoughts. 

Last Words on the Cozoy D1 

Friends, this is the 1st iem I’ve ever heard from Cozoy and I gotta tell you, I am very-very impressed. I am not the type of reviewer who will talk down or trash a set because it doesn’t carry my specific favorite sound signature, like so many do. I can recognize something good when I hear it. This is called subjective-objectivity where I can separate what I most desire and see the good in what I’m hearing. This was the D1. Typically, I like a hair more warmth. I like a touch more bass presence. However, tell that to my auditory cortex because I have enjoyed the D1 for weeks now. Picking this set over much more expensive iems which do fall into my preferences. The price to performance is flat-out great folks. 

P2P (Price-to-Performance) 

I think that’s what is hooking me the most. Everytime I do a review of a solid ultra-budget offering I am always struck at the price to performance aspect. I’ve always enjoyed high sonic benefits from ultra-budget iems. There is something about getting a high-quality sound for cheap which has always intrigued me. I think when you grow up without many resources and basically poor by US standards, you tend to enjoy anything which performs well for less. There are a multitude of solid choices between $25 and $45 and the D1 can perform favorably against almost all of them if your preferences align with the D1’s signature. I think this set is an easy no brainer at its cost. Cozoy really did a nice work on a balanced/neutral sound that is both musically gifted as well as technically astute for the price of McDonald’s for three. Well, two anymore, but you get my point. We should celebrate brands who do more for less folks. Sure, they want to make money, but they understand that we want to save money and so they land at a happy median where performance and sonic ability beguile the consumer and the brand hopes to sell thousands to recoup costs of doing business. I truly hope that the D1 catches on because the P2P aspect of this set is high. 

The Why… 

Because everything I’ve said all review is “why” the D1 is worth every penny and a high price-to-performance style set. Perfect for anyone who doesn’t want to spend an arm and a leg to get quality audio, or for anyone who simply wants to check out iems for the first time. In fact, the D1 might be one of my first recommendations. It’s comfortable, built well, lightweight, no wear fatigue, and it looks so cool. Also, it comes with plenty of accessories for the low cost of $30. But it all comes down to sound. This is what we truly care about.

That Sound!!!

The D1 has that almost perfect Harman dynamic balance with a focus in the sublevels and a focus in the upper mids. Nothing egregious, no area of the mix usurping dominance over the rest, and each area of the mix seems to blend well in a perfectly cohesive sound. This set also has great clarity and resolution. I wouldn’t say it punches above its price because I hate saying that, but the D1 can handle itself readily against higher priced sets. Especially against those sets which carry its Harmanish style signature. It has a speedy, punchy, and commanding bass without being oversaturated at all. A deep sub-bass, very tightly compacted, nothing soft, and it rises to the occasion. The midrange offers fantastic female vocals with clarity and transparency that is very nice. Every now and again you’ll hear something a tad too sharp, but for the most part the control over the mids is fantastic. Also, the treble has bite, has sparkle, and good extension making an airy and open sound while still sounding cadent & smooth. Technically the D1 stands out with good detail retrieval, solid note separation, good imaging for the cost, and a solid stage all the way around. Again, a no brainer. Well done Cozoy. 

Conclusion 

To conclude my full review and feature of the Cozoy D1, I first have to thank my friend Tony Liu who is my contact at Cozoy. He is one person who demands that I be honest because it helps him grow and it helps his brand grow. Seriously, I have the text messages to back that up. Friends, that is called integrity. You either have it or you don’t. He does, which means that Cozoy does. He asks for nothing but my authentic feelings and that’s what he requests makes it to publishing. Thank you Cozoy. Also, thanks to the reader (you) for taking the time to click on the link and actually read my words. It truly means the world. My partners at Mobileaudiophile.com and I try very hard to make helpful content geared towards helping you find what works for you. Thank you so much. 

Other Perspectives 

Now that you’ve read my words I have to ask that you would read somebody else’s words. We all know that this hobby comes with a lot of diversity and a lot of subjectivity. We are all different, we don’t hear the same, we don’t like the same music all the time, we don’t have the same gear, and we simply don’t have the same likes and dislikes when it comes to sound signatures. It’s the differences which make this hobby so amazing, but it’s also the differences in each one of us which forces me to plead with you to check out other reviews. Do not hang on my words. Granted, I will never lie to you, and I will always tell you exactly how I feel about any product that I review. That is my promise. My words are my words folks. I don’t use Ai, I don’t cheat, I don’t read other perspectives before I write my own. You are getting my true-blue perspective every single review. However, I am not the next guy, and I am not you. I want you to get your purchase right so that you can enjoy what this hobby is all about… music. And with that said, it’s time for me to check out. So, please take good care, stay as safe as possible and always… God Bless!! 

 D1 Pros

-Price-to-performance 

-Great resin build for $30. Looks more expensive, it’s light, no wear fatigue, and it sits in my ears perfectly 

-Also, that design is so awesome. I love minimalist, classy, and elegant with a hint of zest, that’s the D1

-Not a bad unboxing too featuring a dope electric purple cable which solidifies the dopeness of the whole aesthetic 

-You can’t go wrong with balanced/neutral, a touch of sublevel depth, and a sparkly treble. The tuning is great for the cost

-Bass hits quick and  leaves a mark. Definitely a moderately lifted but punchy sound down low

-I find the midrange to be the focus. Females sound delectable, low glare, highly technical 

-The treble sparkles with air inducing extension and controlled crispness without abrasiveness or grain 

-Detail retrieval 

-Imaging for the cost

-Somewhat layered from top to bottom and front to back creating a well dimensioned sound field, again… for a budget set

-A tuning you cannot go wrong with which has the potential to be an all-rounder

D1 Cons 

-The bass is moderately boosted. This can be a problem for many. Quality-over-quantity doesn’t suit Mr. Basshead

-There will be moments of shout in obviously shouty tracks. Perhaps fatiguing over long periods 

-Eartips are oddly small, reminds me of true wireless eartips

-Nothing else at $30