When mastering my audio and saving it as a .wav (usually in Soundforge) then encoding to mp3 format, I usually get a fairly decent result -- as long as I listen to playback on Windows Media Player, RealPlayer and a couple others.
It seems as though the default playback software device on most websites is Quicktime (is that correct??) and the playback, in contrast seems VERY boomy and bass-heavy to me. Is this the usual? Do I need to readjust the EQ just for Quicktime while mastering? I'm a bit confused and frustrated!