64 Audio U4s In-Ear Headphones

great bass

The U4s are amazing kilobuck IEMs. I switched to them after using the IE 600. While they’re not as comfortable or compact as the IE 600, the sound quality is significantly better. The U4s excel in tuning (I can finally hear the mids clearly), channel separation, and bass performance, easily outperforming my previous IEMs. The sound is highly detailed, and frequencies remain distinct without overlapping, unlike the V-shaped tuning of the IE 600, which I didn’t particularly enjoy. I also noticed that the Apple dongle is sufficient for driving them; there’s almost no noticeable difference compared to my Astell&Kern HC3, except for a slight improvement in low frequencies. I’m really enjoying the U4s!

The the pressure relief system is game changing. Don't know if I'll ever be able to go back to other iems. That aside, it's everything I wanted out of the SA6 MKIIs. Smooth u-shaped but this time with stellar bass performance!