After the HM6, I tested the newer HM7, which have the same drivers, as proven both by the specifications and by measurement. However, these pretty and well-constructed gems sound much better! The lows have slightly improved, but the highs have improved noticeably and now the sound is crisp and precise. It is also slightly louder. It may have something to do with the much wider nozzles, or the wider tips you get with them. Anyway, these share the same qualities as the boarseman CX98 - a bright and precise sound, with a moderate bass response and slightly less brightness in the highs.