.

Just a quick question as I'm considering pulling the trigger on the HD600. How do they sound with fast music such as hard rock and metal? I have owned the HD650 twice and enjoyed it but found it too slow and dark for rock and metal.

I'm very new to my HD600s, an still finding out how to make them work my sadly-non-standard ears. I found the bass a little unclear, but the fix for this was reducing it a little. by cutting a little bit around 100Hz, I found I could increase below that without loosing the sharpness.

It's ongoing, but, at least for the music I was listening to last session (another coming up now) I'm fairly happy with the result with just EQ, and, as I'm listening from a PC, EQ is easy. Hmmm... Easy to put there, at least, harder to learn.

(The thing I have to fight is the tendency to want to make the curve look right, rather than simply listen to the results. Damned brain! The other thing is that my HF hearing loss is sufficient that I now no longer know what "flat" is. Something that I can enjoy is the best I can do. OK, so, in a way it doesn't matter, but in a way it does: I always rather liked the old-fashioned definition of hifi, reproducing the recording accurately.)

Material slipped in front of the driver and under the pads will primarily smooth and tone down upper mids and treble. Material placed behind the driver in the cups will mostly tone down bass. I don't think I have pics, but it's really as simple as cutting out oval discs of the material I used and placing them where they need to go.

Yeah, if the upper-mid hump is bothering you, try out that 1/8" open-cell foam I mentioned. It works fairly well. One or two layers depending on your tastes. You may find even better materials with experimentation. Also don't underestimate what a lesser clamp can do for the sound. More comfortable, if you have a big head, and helps bring back upper treble that the foam might smooth out.

I think the HD600/650 drivers could be swapped. Not sure if everything about the enclosures are identical, but at least that whole part looks the same. Maybe. Can't say I've tried.

Interchangeable but not the same.