I've been playing a bit of BLOPS2 lately.
When you get hit with an EMP from the enemy, WOW! Incredibly low and powerful bass coming out of my F15HP sub. The first time it happened, I just about jumped off the couch. I didn't realize that it was part of the game until a split second after.
You can get a smaller taste of the subwoofer action by equipping an EMP grenade and letting it go off at your feet.
Highly recommended to see just what a good sub can do!