Originally Posted by MattTCG
^^ Wait, did you say that the he500 is the LEAST balanced of the HFM?
Yep, and I stand by it ^^
Even with their VU-shaped sound signature, the 4s are more balanced throughout the spectrum (the alteration is at both ends and is regular, yet fast).
The 500s have a mid-bass and upper-mid bump (which gives their warm/lush yet open sound). They have an uneven spectrum which, IMO, makes them the least balanced of the the bunch (again, 400s not taken into account, these are flawed :D).
The 5LEs are more balanced than the 500s. Compared to the 4s I cannot tell. They have a (very) slightly raised treble and less bass than the other Hifimans (but the other Hifiman in question all have a boost there: sub-bass for the 4s, mid-bass for the 400s/500s. The 5LE might well just have a neutral bass).
Darryl can chime in for the 6s ;)
Edit: oh! and the Mad Dogs are the most balanced of them all