He probably had some sort of positional software running, which tends to sound as if things are echoing off the walls of a metallic chamber. Creative Soundblasters, Dolby DCSS (I think it's called) and other gimmicky positional technologies all severely mangle audio fidelity in favour of more accurate sound location in the 3D audio space.

I used to play games with those technologies and they do help to some degree, but then I yanked my Soundblaster out of my PC and put an Asus audiophile card in that I had bought ten years prior and didn't open and there's no beating a good stereo setup with quality sound that hasn't been coloured by that gimmicky positional crap. I use ATH-M40x headphones.