I am intrigued by this "more bass/bassier" concept that frequently comes up in this forum, especially relating to the M50s and their peers. Is there really such a thing as 'MORE bass' in the better brands of headphones or are we talking about different bass characteristics. Are we talking about natural bass as opposed to a contrived sense of bass where a set of cans are tuned to overemphasise (read distort) the bass signature of a recording?
To me, when auditioning any piece of audio equipment, there are two touchstones that should not be ignored - the sound of piano and the sound of the human voice. Both should sound natural because if they don't, then after a while this starts to grate on your ears (well mine anyway). Accurately reproducing the lower registers of a piano with their complex harmonics is an extremely difficult task which few (if any) headphones actually achieve. The good things is that a number come very close. The human voice is another kettle of fish entirely and if you look at the fact that we have never come close to reproducing it well electronically you can see what I mean. This is despite the fact that our voices only cover a modest part of the frequency range of our hearing. Whether it's Lady GaGa, Sinatra or Pavarotti you really want to hear their voice reproduced as naturally as possible don't you? The answer to this from most people on this forum who play a musical instrument would be yes I suspect. It would be interesting to see what type of headphones these forumites own as opposed to the dedicated listener who does not play a musical instrument.
I auditioned the M50s (yes, they were not burned in) and after putting them through their paces with what I call my reference recordings I dismissed them. The bass was overemphasised to a point where I could palpably feel the thump but I couldn't hear the pitch of the note or more importantly, the line that a bass guitar was taking. On a recording with the great Robbie Shakespeare in full flight in the background, the musical line was lost because while I could hear the notes the pitch was vague and indistinct. The Senn HD380s I was auditioning at the time were much more faithful to Robbie's note making though with a little less punch.
So to me the likes of the M50 (I've only singled it out because it is frequently mentioned here) do things to bass notes that are not really natural and distort the music. If you are into music that is artificially altered in a studio setting then I can see why headphones which have been tuned to overemphasis the bass might be very appealing but to me this is the result of deliberately distorting the bass signature with a subsequent loss of detail. BTW, I didn't buy the Senns either.