@Slater can you comment on isolation of zs4 and hopefully its sub-bass
or maybe how they basically feel in your ears
Awesome isolation. They are the next best thing to wearing earplugs. I have used them to mow the lawn with loud gas powered tools, and I can hear my ZS4 music perfectly. I can drive in the car with both windows rolled down and my passenger listening to music on my car stereo, and all I can hear is my ZS4 music. They basically isolate you in your own world of music. That can be good and bad though. I wouldn’t recommend them if you need to hear anything around you (car horns, sirens, etc). And you definitely won’t hear anyone talking to you, even if your music is low. If you’re wearing the ZS4, and pause the music to speak to someone, you still have to put your ear quite close to hear them (or else remove 1 of the ZS4 ear pieces).
The only down side to the extreme isolation is if you really insert them deeply you risk a suction-like effect and the music sounds muffled. The ZS3 suffered from the same thing. It doesn’t happen all of the time though, and when it does all you do is adjust the earpiece fit and you’re good. Or tinker with different tips, or just don’t insert it super deeply.
The comfort (for me) is superb. It fits exactly like the ZS3 if you have that. I can wear them all day with no soreness. They are my most comfortable and best fitting IEMs. It does vary though, as others have said it doesn't for them. Although I think some of them are just situating them in their ear incorrectly. I've seen people orient behind-the-ear IEMs in some totally odd way, then claim the IEMs fit terribly.
The sub bass extends deep, hits hard, and the sub bass and bass is very clean and seems quite fast. If you want a club experience, listen to EDM or similar bass heavy genres (rap, dubstep, trap, etc) the ZS4 will put a smile on your face.
It’s well worth $12. And the cable is great (the y split is super low, but it is low on all KZ upgrade cables).
On a side note, the TRN BT10 cable came yesterday, which I like a LOT. And it fits the ZS3 perfectly! The ZS4 volume with the BT10 is reduced some though (and the sound gets degraded slightly). I just don’t know yet if that’s due to the cable or the ZS4 itself.
The ZS
3 was power hungry, and had a similar degradation when the KZ Bluetooth cable was used. And that turned out to be the cable just not being able to provide enough power or maybe an impedance thing.
I just need more time with the BT10 and other IEMs to figure it all out.