Driver: Single 'SIREN' balanced armature
Sensitivity: 113 dB SPL @ 1 kHz
Impedance: 69 Ohm @ 1 kHz
Frequency Response: 20Hz - 20 kHz
Cord: 0.60m + 0.90m extension cord
Weight: 10 grams
Plug: Gold-Plated Stereo 3.5mm Mini-Plug
Packaging, Accessories, and Build Quality
One thing that can be said about all JAYS' products is the consistency of their quality. s-JAYS, though not on the higher end of JAYS' lineup, still packs a box full of goodies that will put some big brand names to shame. There are the earpeice itself, the extension cable, five different sized eartips, a foam tips, some filters, an airline adapter, a signal splitter, and a small leather case. One thing I'll like to see is a shirt clip, which I think should be included in all IEM package these days.
Despite the bulky looking of the earpiece, it is actually very light. The strange alien / bee / bug design doesn't affect the its comfort at all. In fact, I find it more comfortable than q-JAYS. The two pieces cable is a bit too long but not really of any major concern. Unlike the q-JAYS, which I have issues with the cable weight and the inability of the earpeice to hold securely in the earcanal, the s-JAYS is holding itself plus the cable firmly in place. The only design flaw I can see is the Left / Right marking on the earpeices. They are on the strain relief and tiny in size. I almost missed them entirely on the first inspection and wonder how i could tell which side it is. My suggestion to JAYS is, use small red / blue color dots on the different side of earpeices instead of tiny L/R marking.
Like all JAYS' IEM, s-JAYS uses the same filter paper to block out earwax from getting into the nozzle. It has been suggested many times (from other threads) that the filter paper may actually have done its job too well and often gets clogged up too easily. Beside getting more filter papers, I'll suggest those of you who has a lot of earwax switch to foam tips, which seems to prolong the filter life. Of course, you can always try to keep your ear canal as clean as you can
A comparison to s-JAYS' big brother, the q-JAYS.
I gave the s-JAYS a standard 50hrs of burn-in before the review (like I did with all IEM I reviewed), but I didn't notice any major change in sonic signature (perhaps it is too subtle for me to tell, but I won't know). The SIREN balanced armature transducer, which I believe is made by Knowles Electronic, is advertised by the manufacture as to "maximizes bass performance" - and I agree. s-JAYS by far has the second best bass performance on any single balanced armature IEM I have heard of, out-shined only by Philips' SHE9850. Though the bass is big, it is not the deepest. The prominent mid-bass tend to overshadow the rest of the bass frequency (and this is where SHE9850 has done better). Nevertheless, the bass performance is still impressive and commendable.
Mid on s-JAYS is warm and slightly congested, even sounding a bit recessed at times. It gives a more mellow signature to the overall tone. Strange enough, it also gives me the impression of more distance on the lateral side than on the depth, making better separation yet not as good on soundstage. In some sense, it actually gives me the impression of an earbud fitted closely to the ear canal.
Treble is a bit roll off. There are still a little fine detail but it doesn't stand out much between the strong bass and the warm mid. The good side is of course there is no sibilance to speak of, but the lack of sparkle and fine detail might not be what you are looking for.
On extra note, I tried a few portable amp with s-JAYS and find the improvement really worths the time. In general, the mid is lifted more up-front and less congested. Speed, soundstage and detail are also improved. It seems to perform closer to what i would associate to how balanced armature would sound (and perhaps that's just a personal taste). Though I won't say s-JAYS is anywhere near the level of difficult-to-drive, I do recommend trying it with an amp if you can.
In all, I'll describe s-JAYS sound signature to be warm, mid centric, laid back and very smooth - not very much on detail but have a good bass performance.
s-JAYS is a very curious sounding IEM. It doesn't sound like typical balanced armature based IEM yet it is not quite dynamic (moving coil) sounding as well. It gives me the impression of a hybrid especially when it is unamped. When amped, it does sound more "balanced-armature'ish". Thought not very difficult to drive, I do feel s-JAYS benefits from the extra power of an amp. JAYS has been marketing the s-JAYS as their lower end entry class, and I do think they have priced it just right for its SQ (U.K. price is about US$80, last I checked). It is definitely a good choice for stress free long listening session, and the alien / bee / bug shaped earpeices are a plus for those who want something unique.
For a quick sum up, you can read this