Well I got back my old Sennheiser HD 545 and I'm comparing the two. I'm surprised how similar they sound to the HD 600. They really are of the same family. The HD 545 has a channel dropout issue, so I put it's driver baffle in the HD 600 frame and it seems to of fixed the issue. I put the HD 600 drivers in the HD 545 frame and it became more comfortable due to the HD 545's wider headband and lesser clamp. The HD 545 is a bit brighter, more spacious, and leaner than the HD 600 sonically. This has some advantages as the HD 545 sounds clearer and more beautiful in some aspects. The HD 600 sounds darker, warmer, and deeper. Both are very smooth up top. I need to listen to both more on numerous genres to see if I can note any refinement differences as I only compared them on a couple songs so far. They are closer than I thought. The different housings don't seem to make much if any sonic difference to the HD 600.


Left: HD 600 Driver. Right: HD 545 Driver.


Left: HD 600 Driver. Right: HD 545 Driver.