Originally Posted by tonmeister
I find the HD650's very smooth & relaxed through the mids & tops, quite flattering if there are any harsh hi mid frequencies. I think this makes them better for audiophile applications than for engineering, (kind of an enhanced "warm" tone) I prefer more bite in the high mids, when there's something in there that needs sorting out - I want to know about it! that said, I cant say i've heard any alternatives as good as the HD650. (i dont think they are particularly ruler flat thats all)
Actually the problem is likely that they are very flat and that does not make a headphone sound natural unless binaural recordings are used.
This is the explanation I have found:
When sound hits the head from a distance we will see the HRTF effect. This means that there will be a little something like the baffle step in speakers or microphones which for the human head means upper midrange. When we listen to a headphone that measures flat we loose this small natural lift in the upper midrange and the result is the warm relaxed sensation as we get from HD650. The older HD600 has a slightly different response and hencce sound slightly more natural in the midrange.
OTOH it's easy to hear that HD600 lacks a little in the lowest octave.
My solution as I have mentioned in other threads is to EQ (bringing down a bit in the 80-300Hz range) the HD650 which results in an overall better response than HD600.
Yellow = HD650
Green = HD600
Measurements are taken with an Earthworks QTC1 between the cup and ear with phones on my head.