I've had these headphones for about 3 years now. They sound much better than your average run-of-the-mill headphones (obviously). Richer bass, mids, and highs. I recommend downloading the latest drivers from HT Omega's website, then double-click on HT Omega driver icon in your taskbar tray, and use the ROCK setting under voices/presets.
Said voice/preset sounds the best for all genres of music, in my experience! REALLLLLLY livens up the HD555!