The Ear Force X51s are real surround-sound headphones, with front, rear, and low-frequency drivers in each earpiece. They also have a removable microphone for interactive gaming and Internet telephony. The surround sound actually works with a 5.1 sound card, and it's sufficiently accurate to locate things behind you when you're gaming. The fidelity, however, is all midrange, which makes explosions disappointing. These aren't music lovers' phones by any stretch. They're loud, though, managing 107-dB peaks.