Fixed it, strange strange issue... I rebooted at least a dozen times to no avail, tried reinstalling drivers, rolling back bios, everything you guys did; nothing. I let the battery die, charged it, turned it on and it was fine???
Just happened to me, same exact scenario... was playing Diablo 2, then went to hutdown my computer. Went to boot it back up, bottom bass speakers don't work. This has to be a hardware issue, shame on asus for this low quality control.