While this is Cayin’s first entry into the world of IEMs, they clearly did their homework designing the shape and choosing the material of the shell. Cayin went for a more premium look with an all metal, machined CNC shell using aviation grade aluminum alloy material. The shells have a smooth gunmetal finish and a very ergonomic shape which fits comfortably in my average size ears. The inner-shell part has smooth rounded edges, and on the outside, you have a faceplate with a hint of facet design and 3 hex screws, giving it a more industrial look.
The nozzle is stainless steel, with a lip for a more secure eartip fit, and you will also find a stainless steel mesh cover. Other details are L/R print on the inner part of the shell toward the nozzle, and red/black ID dots next to 2pin socket, making it easier to match and to connect the cable. There is even a Cayin name along the edge of the faceplate, but it’s a bit hard to see. I know Cayin wanted to keep the faceplate clean, but I would have loved to see something on the faceplate to showcase Cayin brand, even something very simple.
Under the hood, inside the shell, Cayin decided to go with a quad BA design, using dual Sonion BA woofer and dual Knowles BA Tweeter. Nothing more or less to say about it, except these have an average 30 ohm impedance and average 113dB sensitivity. The sound analysis in my follow up section will go into more details how Cayin put these 4 BA drivers to use, shaping the signature of their debut IEM. Perhaps, with 4 BA design Cayin left the door open for future hybrid releases where they can either add or replace one of the BAs with DD. Only time will tell!
I analyzed YB04 sound performance paired up with N6ii and LPGT while playing a variety of test tracks, such as Agnes Obel “The curse”, Sandro Cavazza “So much better” (Avicii remix), C-Bool “Never go away”, Ed Sheeran “Shape of you”, Alan Walker “Darkside”, Galantis “Hunter”, Iggy Azalea “Black widow”, Indila “Boite en argent”, Counting Crows “Big yellow taxi”, David Elias “Vision of her”, and Michael Jackson “Dirty Diana”. Even so I let it play for a few days before starting my critical sound analysis, I didn’t notice any changes in sound before and after this burn in period.
I found YB04 to have a more neutral-balanced sound signature with a slight tilt toward the mid-forward emphasis which varies depending on source pair up. The tonality is natural, non-fatigue, with a decent level of clarity and detail retrieval. While not exactly revealing, or analytical, or having a high level of micro-detail retrieval, the sound is presented in a very natural, organic way without being too smooth, or too warm, or congested. I don’t want to make it sound like YB04 has a safe neutral tuning. It’s just not for those who want extra bass impact or more treble energy. Instead, it will please those who enjoy extended listening with a non-fatigue natural clear sound. The level of clarity is what surprised me the most in their tuning.
Bass has a good extension, down to sub-bass rumble, but this is a kind of rumble you can hear, rather than feel it. Mid-bass impact is more neutral. Lower mids are more neutral as well, giving upper mids more natural transparency. Upper mids/vocals are clear and detailed, natural, not as layered or separated, but at the same time not congested. As already mentioned, mids/vocals sound natural, clear, and realistic without being too revealing or too smooth. Treble has a very good definition, more natural, less fatigue, good extension, but not too much airiness.
Soundstage is wide and with a depth that has a nice out of your head spacing, but I don’t find it holographic. It’s more spreading left to right. Imaging is pretty good, with accurate placement of vocals and instruments. No complaints here. Layering and separation allows to easily identify and distinguish every sound, but due to a more natural tuning don’t expect to hear too much air between the layers.
In many cases picking the correct eartips size is important to achieve the best seal, especially to finetune the bass impact. Or you can try different material eartips (silicone vs foam) to reduce upper end sparkle. With YB04, Cayin included a big variety of different eartips. Here is what I found while comparing them.
Bass eartips (black stem core, wider bore opening) – slightly v-shaped sound with a little more emphasis on low end impact and lower treble peaks. Give you a better seal.
Vocal eartips (red stem core, narrower bore opening) – gives more emphasis in mids and lower treble, bringing vocals more forward with extra crisp details. More relaxed seal.
Balanced eartips (grey silicone) – yields a more neutral-balanced signature without too much extra emphasis across FR bands. It helps YB04 to achieve its more non-fatigue sound without pushing upper mids or lower treble too much forward. Average seal.
I ended up using Balanced eartips in all my comparisons, pair ups, and sound analysis. With YB04, I found eartips selection to have more impact on the sound change, though YMMV since we all have a different ear anatomy.