I tried it both on my home system (Yamaha HTR-5150) with several CD's and also on my PC (Hercules Game Theater XP - latest drivers) with many different MP3's.
I have the equalizer turned off, it's just straight sound at normal levels, music varied from but it's noticeable with hip-hop music the most.
I believe some people reported something similar to this at a certain point during breakin. It should go away within a few hours. If not you may have a problem.
Headphoneus Supremus: Found that torchiere lamps induce nicotine addiction in moths.
Join Date: Dec 2001
Location: Seattle, WA
Posts: 3,106
I would let them play over night, and if the problem doesn't go away, then RMA them. The HD280 is strange about break-in; giving them time seems to cure a lot of problems.