My HD600 and HD650 could be puke colored or neon green or be hot pink with black flamingos and I'd still listen to them. I care about the sound.

They are not quite like the AKG701 (although more than the HD600 are) but I think those are a bit unnaturally thin at the end of the day.

Maybe because I'm using a solid state Benchmark DAC1 PRE to drive them, I don't know, but I'd hardly call them unnaturally veiled or muddy or laid back, the treble is very crisp and present, maybe just a shy weak on one little segment of the low treble (where the HD600 is too high), but that...

That's weird since I find they have tons of separation between sounds, more than the HD600, if anything almost a trace too much.  

I can't tell if I have black or white. It looks half way between black and white! It clearly looks darker than the white parts on the center ring. It sort of depends upon the angle of the light and it can look fairly light or considerably dark.   Probably the white though. Got them late 2011...

My take on the HD600 vs. HD650 which I have both owned for a few years. Running them on Benchmark DAC1 PRE.   The HD600 seems to have a small artificial hump in the treble right where it messes up violins a bit and tends to make most music sound not quite truly live like you are there in the...

I'm surprised to hear that since the HD650 have pretty strong bass and any more and I'd say it would be totally fake and booming.

Oh yeah they both leak like crazy (same for AKG 701 and most open ears really).

Well it's a very different story over here (not sure why the compare tool is not working, but here are each separately): https://cdn.shopify.com/s/files/1/0362/2465/files/sennheiser_hd_650_frequency_response.png?4746...

I have to disagree, getting near to be perfect but a trace weak on certain bass elements and a very noticeably treble quirk that is pretty important.

OTOH the HD600 seems to have a small artificial hump in the treble right where it messes up violins a bit and tends to make most music sound not quite truly live like you are there in the room with it since the hump seems to mask stuff just about it, in a sense.   Anyway I did a lot of...

Hmm they sound way too different to me for it to be the same driver. I can easily tell them apart, instantly, on any music.

Wow, HD600 sounds more veiled to me.

It's weird but to me the treble seems more veiled to me on the 600 than the 650, maybe I have weird copies of one or the other or both or a quirk in the shape of my ears or something.   650 doesn't sound any warmer to me at all, although it has more bass but the rest doesn't sound warmer to...

I don't know. Maybe copy to copy variation? It definitely seems larger and freer comparing my HD600 to my HD650.