Review on 🎧 Yinyoo KZ ZSX 5BA 1DD Over Ear Earbuds: Superior Noise Cancelling Hybrid Headphones with Balanced Armature Dynamic Driver (Black, Wired, No Mic) by Allie Hull

This is an updated rating after 2 years of use and no more than 50 hours (mainly during flights). I've tried and tried to make them my #1 IEMs, mostly because the frequency spectrum is split so part of the spectrum waves can't affect sympathetic or harmonic waves like it does with single or dual driver audio in the case is. Playback systems, regardless of size. With the ear interfaces included, I found it uncomfortable after just a few songs using all 3 sizes. Installing the foam pads has SIGNIFICANTLY improved several aspects. Perfect seal every time and no ear canal pain or wear and tear fatigue. The foam tips also reduced outside noise significantly, approaching active noise cancellation. That being said, I still have the AKG K390nc, the original active noise canceling headphones, the same foam tips as in them that made it possible to achieve absolute silence during flight. Back to the ZSX, a few months ago I noticed some strange bugs. in parts of songs that I know very well as a musician and as a physicist. It sounded like parts of the same instrument (guitar and drums in Pink Floyd The Wall Pt.2 or 3) had a delay that went in and out and sounded different each time. When I listened, I almost heard a mid-bass hum, like the valve had reached its limit, released excess pressure, and started over. *** This ONLY happens in the left IEM, the right side seems normal. I have several dozen "test songs" in which I know every instrumental part inside out, and the more I listened to the strange behavior of the KZ ZSX 12 driver, the worse it got. At the moment it is difficult to consciously listen to music with them.