Cayin YB04

Cayin YB04 is a first IEM by Cayin. It is priced at 499$ and has a lot to prove. Spoiler Alert : It does.

Cayin YB04 is a first IEM by Cayin. It is priced at 499$ and has a lot to prove. Spoiler Alert : It does.

Sound quality

Rating: 9.5 out of 10.

Build quality

Rating: 10 out of 10.


Rating: 10 out of 10.


YB04 impresses from the very first thing you’ll do, which is opening the box. Inside, you’ll find twelve pairs of eartips, the IEMs themselves, a 3,5mm terminated cable and a leather case.

The case is one of the best I’ve seen to date. Made of leather, magnetically closed, with lots of space inside and padded with soft material to ensure safety of our new in-ears. It can easily fit two pairs of IEMs, but hey, I don’t really recommend it, as they could scratch against each other.


The cable included in a box is a very pleasant suprise. It’s an 8-core, hybrid wire terminated in 3,5mm jack. On the other side, the cable plugs into the IEMs by 2-pin connectors, which work flawlessly and ensure that it won’t get disattached on it’s own.

Build quality

The build quality of Cayin YB04 is simply put – splendid.
The IEMs themselves are quite heavy, thanks to sporting a full metal body, but boy, oh boy, these things scream premium. Finish is excellent, all ridges and edges are perfectly made, and you’ll be far from cutting yourself.

Additionally, i adore the design and overall look of these. Those visible screws, big and chunky shells, beautiful texture makes me sing with delight. In terms of build quality and accessories, i haven’t seen a debut that good…well, ever. Chapeau Bas.


YB04’s comfort reminds me a bit of a “pink elephant”. You see these big and heavy shells and you assume, that these won’t be too comfortable. Well, youre kinda right, and kinda wrong. They are not a very comfortable pair of IEMs, but they aren’t uncomfortable. See what i mean? These are nowhere close to the level of Fiio FA9 or any custom in-ear, but at the same time they’re not fatiguing like Campfire Solaris or Sony IER-Z1R. Comfort of the YB04 is decent, its okay, and for the shells that big and chunky, im actually pleasantly suprised.


These beauties sing thanks to four balanced armature drivers, from which two are the Knowles tweeters, and two are the Sonion woofers. I personally adore Sonion drivers being responsible for the low frequencies, as im yet to find an IEM that has a bad bass/lower mid using these.


If you’ve survived to this part you’d already know that in my opinion Cayin made a spectacular debut to the IEM market regarding the build quality, accessories and just an overall design. But all that would have been for nothing, if the sound ended up being poor. Well…

I could describe YB04 in two words, which are : Neutral, natural. But hey, that’s not it, lets dig a bit more into it.

I said that im yet to find a bad sounding bass on a IEM using Sonion driver. Yes, im in for a longer wait then. The bass in YB04 is fast, resolving and greatly extended. I’d say that it is very mature and it sound’s just like it should in some way.
It’s performance varies on the music you’re gonna listen to, but it’s always pretty true to world. When it has to be punchy and bloated, it is. Not by a huge margin, but it has this slam and it tends to make your head bob.
But at the other hand, when talking about bass guitars or a contrabass, it pronounces every single touch of the string with great class and sophistication. Actually, it reminds me a bit of Campfire Andromeda, but is definitely less bassy in the overall quantity.

The midrange is colorful, analog and just beautiful. It has a very natural timbre to my ears, vocals and natural instruments sound just like it should, without even a slightest sharpness or overexposure. Mid’s are quite calm and lush, doesn’t sound aggressive or overly forward. The closest resemblance for midrange in the IEM market i can mention is definitely Meze Rai Penta. Meze has this lovely timbre, sounds just very pleasant and rich. I find YB04 to be quite similiar in this regard.

The Treble is very neutral to my ears. No spikes, no harshness, sybilances. But also, it’s not shy, dark or veiled, hell no. Imagine the Campfire IO, with this slightly sweet, but yet pronounced and saturated high frequencies, and you’ll get what i mean. Great detail retrieval, cymbals sound thick but edgy at the same time. Keep in mind, that pairing these with an overly bright and sharp source MIGHT end up with a very forward and sharp treble response. Plug these into the Cayin N6ii or a Sony WM1A and you’ll be blown away.

As for the soundstage, it is very good, but it ain’t anything crazy. I mean, the imaging is spot on, airiness and separation is quite pronounced and the overall size of the stage is natural. Yet, Rai Penta offers a quieter background noise, which result in a more convincing and spectacular effect of music coming out of a complete darkness. Anyhow, these have great soundstage – its tidy, airy and images well.


Im still suprised how marvelously Cayin has stepped into the IEM game. Pricing your first model at 499$ could be a risky game, but i believe it was a great choice.

Perfect build quality, fantastic accessories (that case!), beautiful, industrial design and a very competitive sound quality with a lovely, yet safe timbre. Cayin YB04 has it all to be called the best IEM for the price. I believe that soundwisely this is what the Fiio FA9 wanted to be, but they fall short in comparison. I already can’t wait for the next IEM by Cayin, but till then…YB04 are HIGHLY recommended.

Gear used during this review for the sake of comparison and as an accompanying equipment:

  • IEM – Lime Ears Aether R, Lime Ears Pneuma, Campfire Audio IO, Andromeda, Solaris, Fiio FH3, Fiio FH5, Fiio FH7, Meze Rai Penta,
  • Source – Smartphone, Cayin N5ii, Fiio M11, Fiio M15, Cayin N8, Shanling M5s, Sony ZX300, Sony WM1A, Shanling M6.