Well, it's a fun conversation, so might as well enjoy a stimulating debate as much as you like, so I guess I don't mind off-topic :)
Anyway, in my experience: No matter who you are, if you listen to EQed HD650s and SRH940s, it's clear that the SRH940s treble is a league ahead of the HD650 (clearer, more detailed, more clean, fast, less or same siblance). Similarly it's also clear that the HD650 bass impact is a league ahead of the SRH940 (stronger, more energy, smoother, more dynamic range, etc. although a bit slower and muddy). Sure, neither headphone is better overall because they have different strengths and weaknesses, but it's stupid to say that neither is better or worse in any area. The SRH940 dominates in treble and detail, and the HD650 dominates in bass, and not a single person who has heard them both would say otherwise. It's just not a subjective thing. You don't have people saying "Wow this SRH940 has head-shaking bass vs the HD650!" or "Wow this HD650 has beautiful highs vs the SRH940", because that's just not true.
> More, extended, focussed, highlighted, clear, peircing, sibilant; the asumption is that everyone agrees what better treble is.
Huh? Siblance = bad. Piercing = bad. Clear = good. Extended/focussed/hilighted all seem properties of the sound signature / FR response, which is why I mentioned EQing first before comparing. It's way too hard as a human to compare headphones with different FR responses, so the only way to compare is to EQ one to sound like the other, and vice versa.
Obviously you can't just EQ one to sound like the other and expect that to reveal everything, of course. I EQ one to sound like the other, then vice versa, then EQ both to sound like a middle-ground of both sound signatures, then EQ both to be pretty much as FR-flat as I can make them. In ALL of these four types of tests comparing my HD650s with SRH940s for example, I detect the same strengths and weaknesses I mentioned above.
Once again, this certainly doesn't make the SRH940 "better" than the HD650 just because it's more detailed. The HD650's excellent lower end makes it a very nice warm musical headphone when I'm not feeling like listening analytically, or watching movies. The SRH940 has its place where its treble, mids, and detail superiority make it my headphone of choice. The point though is that you can identify better treble, or bass, etc., and it happens that headphones in the same price range do have differing strengths in each area.
Edited by ac500 - 11/14/11 at 5:24pm