I got them this morning. They haven't had time to burn in nor have my ears really had time to grasp any of the nuances of their sound but right off the bat:
- They are definitely extremely neutral. I don't know if they're "flat" per se, but they're neutral and every song sounds like itself. Pretty much sounds like an OEM car stereo captured in headphones. I would be pretty comfortable using these as a headphone reference for mixing/recording. They're flat and analytical without being over-the-top/ugly/painful.
- Not sure I agree with all of the "tank-like build" reviews. The build quality looks pretty much average to me. Not as solid as Shure or Ultrasone (both of which feel like ACTUAL tank commander gear), about on par with M-Audio. I really wish these had a one-sided cable instead of double entry, but that's subjective. The clamp is also very mild. I would like a slightly firmer clamp since...:
- The pads are so big and soft that you won't want to take them off of your head when you're done listening to music. They're like designer earmuffs, so snuggly.
- They are not as detailed or clear as my Shures, but the treble is much less aggressive and the overall sound is more rounded, laid back, "just press play and forget". This is kind of the opposite of what I was expecting. So many people comparing the two said that the HM5s (and clones) are just flat boring analytical headphones and that the Shures are "the same thing plus a fun midbass hump". Yeah, the Shures do have more midbass, and cleaner bass, but these sound much more alive and closer to recreational headphones to me DESPITE being very flat. Nice combo. Reminds you of how much forum stuff is hearsay rather than based on first-hand experience.
- They're not "basshead cans". Bass is just OK. Not as clear or deep as the SRH840s, and from my memory, not as much as the ATH-M50s. I can say I prefer these to the M50s for most things.. Not sure if I like them a lot for electronica so far.
Honestly they sound like an exact 50/50 hybrid of my SRH840s (mid range, overall approach to sound) and AKG240s (natural sounding, but kind of intolerant to high volumes or bass loads), which should in theory be awesome, but I'm not used to them yet.