One of KZ's flagships, KZ ED9, is up for the test. Honestly, I really don't like overly emphasized highs. Too much definition can be exhausing rather than impressive. However, I won't call them bad earphones because of that, because they are quite high quality when it comes to their extraordinary sound signature.
The sound similar to KZ DT5, only with a more balanced bass response (much less sub-bass), and more defined highs.
For slightly more sub-bass and slightly more pronounced highs, you can use any of the filters included with Winintone RG-EB601.
The filters included with KZ GRcannot be used with these earphones, but you can use the filters included with these earphones with KZ GR.
A brilliant sound quality, well defined across the whole frequency range.
Excellent volume levels even without amplification.
The ability to use different filters for different sound signatures.
An excellent build quality.
The highs are just a bit too sharp for me, but it's really not that bad.
Noticeably heavier and longer (as in length) than most earphones.
Seems like the two wide filters I got are different, and they look like they were made of a different material. One of them completely removed any bass from the sound, while the other one just balanced the sound. Make sure the filters you get match each other.
The earphones are slightly heavier than most earphones, and at the same time they are quite long, so just like with KZ GR, they might be slightly loose in the ears.
Lows / Bass
Although the sub-bass is pretty minimal, it's pretty quick and presice. These earphones aren't the basshead's dream, but they offer some of the best-quality bass among KZ's products. The bass can be considered balanced, they leave room for the mids and highs to shine, thus are intended for a more general audience, and especially for vocal-oriented music.
Mids / Vocals
Just like the highs, the mids and vocals are very defined, crisp and dominant. I find them slightly too bright, even slightly sibilant for my ears, but in this specific case it's really a matter of personal preference, and I cannot ignore the quality of these mids.
Highs / Treble
The highs are very defined and you can hear every silent chime and whisle, but it may also causes discomfort because they are so loud and sharp that sensitive ears will find them too bright to handle.