Cozoy D1 Review - A new Challenger is Approaching
Pros:
Tried and proven Harman-like Tuning
Surprisingly technical and spacious sound
Lovely purple cable with 2-pin connectors
Comfortable fit
Cons:
Can sound slightly edgy and sibilant depending on the track
At least a carrying pouch could have been included
Introduction
Cozoy is a new brand founded in 2025 and D1 is their first product. However that shouldn’t deter you from giving them a chance because the founder and the team are all experienced people from the audio industry. They also wanted to make their first IEMs a budget one costing only 30 USD to let as many people as possible get to know them.
Disclaimers
Cozoy D1 has been sent to me by a 3rd party just for me to listen and give my opinion, however I took it upon myself to write a full review as well. Cozoy themselves wasn’t involved in providing this unit. As I always say, everyone is biased one way or another, so take everything you read with a grain of salt. Additionally, I will try to be more concise and to the point in my reviews from now on, without worrying about word count or flowery language. If you have any questions, please ask me in the comments, and I will try to answer them to the best of my abilities.
Packaging, Build and Accessories of Cozoy D1
The price of the IEMs has set my expectations and still I was pleasantly surprised by some aspects of D1 and not so much by the others. D1 comes in a simple unassuming box. Inside you get the earpieces, a lovely cable and 7 pairs of eartips. IEMs costing 5 times more can come with only one set of eartips. 3 pairs of the tips are soft silicone, 3 pairs are double flanged and 1 pair is foam. The cable is bright purple sheathed and soft and the hardwares are metal. Cozoy used the most preferred connectors in the market: 2-pin. I would love to have it 4.4 mm terminated but at this price I know it’s unheard of. The only missing thing is that they could have included at least a fabric pouch just like Dunu Titan X or Tanchjim’s budget IEMs.
D1 utilizes one graphene diaphragm dynamic driver on each side. Shells are made with 3D printed resin. They are light and very comfortable even in my small ears. Nozzles are metal with lips that prevent eartips from sliding off. Faceplates are shiny blue that turns purple under the right lighting conditions.
Sound of Cozoy D1
Tonality
If I had to use one word to describe Cozoy D1’s sound, that would be old-school even though it’s two words. Cozoy went with the now old, Harman 2019 style tuning and I don’t blame them for it. It’s a tried and proven tuning. Just because we found a new target, it doesn’t mean Harman became trash.
Bass is subbass focussed and well controlled. It feels very powerful when the music calls for it and rumbles if the song has deep notes. Mids are mostly clean. Upper mids are elevated and can become shouty. Female vocals sound lovely and male vocals don't exactly sound thin either. Yeah it’s a modified Harman, not one of those thin sounding ones. Still bass and treble is more prominent than mids. Speaking of treble, it’s mostly fine with a good amount of energy. However it can occasionally sound slightly sharp and sibilant depending on the track. Western music didn’t pose any problems but J-Pop tracks were sounding edgy, especially S’s jumped at me when listening to ZUTOMAYO. Strangely enough, there isn’t anything wrong on the graphs either. Treble extension is all right, there isn’t too much air or sparkle to speak of but it’s a single DD after all.
Technicalities
Cozoy D1 is a surprisingly technical sounding set. It has a decent detail level, as much as any well tuned single DD set. However, it sounds so open and spacious that it reminded me of Moritz Dragon, and that’s a 630 USD set. Actually the build and tonality also reminded me of Dragon and I’m more than happy to get that experience for a fraction of its cost. Timbre is also quite good although it’s not the most correct and natural sound.
Comparisons
Cozoy D1 vs. EPZ G20
- D1 is much bassier. G20 have tighter and more controlled bass. They both have decent subbass extensions in their own right.
- They have similarly forward and natural sounding mids with D1 being slightly warmer.
- Overall G20 is brighter and better treble extension but it also feels more even in the treble. G20 doesn’t have the occasional sheen and sibilance that D1 has.
- G20 feels slightly more detailed. They both have similar staging and imaging properties. I mostly preferred D1’s timbre but both have decent timbral qualities.
Cozoy D1 vs Dunu Titan X
- Titan X has a bigger and rumblier bass. Bass guitars are also more pronounced on Titan X. D1’s bass is tighter and more controlled. Titan X’s bass comes as a little pillowy compared to D1’s.
- Mids on D1 sound quite clean and natural. Titan X has an overall warmer tonality. D1 sounds cleaner compared to that. Both have forward mids but Titan X feels more intimate.
- D1 is overall brighter sounding. Titan X’s treble is just right and inoffensive. D1 can be sibilant and peaky occasionally. Neither has a very good treble extension.
- They both have similar detail levels. However D1 is more spacious and better at imaging. Titan X is quite intimate sounding without being closed in. Lastly Titan X’s timbre sounds more palatable.
Cozoy D1 vs. Kefine Klean SV
- D1 has a much more powerful and impactful bass. Subbass extension of D1 is also superior.
- D1’s mids are slightly warmer but still sounds clean and clear. Klean SV’s mids are clearer. D1’s vocals can get shouty but also more engaging. Klean SV’s tuning filters help a lot with the presentation. Gold filters make vocals pop but also cause it to become shoutier. Black filters make the IEMs smoother and easier to listen to. Silver filters are in between and less shouty than D1.
- Treble on Klean SV is again smoother and more refined with Silver Filters. They are more similar to D1 on Gold Filters. On D1, sibilance occasionally comes across but there is no such issue with Klean SV. D1 doesn’t have the excess tizzy aspect of Klean SV.
- Klean SV is more detailed than D1. But D1’s soundstage is more expansive and enveloping. Imaging capabilities of both IEMs are comparable but I’d probably give it to D1 again because of its staging superiority.
Conclusion
If Cozoy D1 came out 3 or 4 years ago, many people would dismiss it as another Harman IEM but we are getting less of these recently. Considering IEMs getting discontinued pretty fast, I think D1 has a place in the market. I like this sound signature and it gave me the experience that’s quite similar to much more expensive sets. This kind of open and spacious presentation is especially rare. I’m looking forward to what they will release next and you should too.