My KZ ES now has well over 200 hours. I think I can assess it now. The boomy bass from whence it was still a virgin has now mellowed down. Also, most of the veil in the mids has gone. I'm also very happy that the KZs, both my ES and EDSE, are very receptive to being equalized. I could raise any portion of the spectrum by over 10 dB and there's virtually no distortion.
Anyway, in addition to the burn-in, I've also had plenty of time to find the best EQ setting for my ES. I've actually managed to find a setting that makes it sound almost exactly like my EQ'ed SHE3580. It's now very balanced in addition to its neutral sound signature. There are some differences though (my EQ'ed ES vs EQ'ed SHE3580):
- There is better extension on the ES compared to the SHE3580. The bass digs deeper and the highs extend farther without getting sibilant. The bass quality on the ES is arguably better imo. It can sound woofer-like without getting muddy. The SHE3580 can't do woofer-like bass, although it's clean.
- The upper mids on the ES are still slightly veiled, even with all the burn-in and my EQ settings. The mids in general are very pleasant though. Male vocals on the ES are noticeably richer compared to the SHE3580.
- Much better decay on the ES. Notes from a synth or bass guitar are delightful.
- Better detail retrieval on the ES from lows to mids. Better detail retrieval on the SHE3580 on highs.
- Better instrument imaging on the ES. Instruments in general sounds crisper and have more bite.
Do note that I'm comparing these with my custom EQ settings that's geared for a more balanced sound. However, the native sound of both the ES and SHE3580 are pretty similar, although the ES is a bit more of a shallow U-shape rather than V-shaped. Likewise, the EQ settings I used for both don't vary too much from each other. The ES just needed a steeper increase in the 500 Hz to 2 Khz region compared to the settings I use on the SHE3580.
Personally, I find the ES to be a superior version of the SHE3590 in terms of sound. I didn't feel that way at first, but after all that burn-in time and finally finding a comparable EQ setting, I can safely say they're the better IEM. I'd describe them as "a more intimate, soulful version of the SHE3580/3590". They have approximately the same soundstage, with the ES everything feels closer and more in your face whilst maintaining their respective positions. I just wish they had better detail retrieval on highs. All in all though, I can finally retire my 3 year old SHE3580 and replace it with the ES as my daily driver.
