So I finally managed to get my sound to come out of speakers other than the bass on my new GT725 in a way that; it’s not 100% perfect, as I think that the subwoofer isn’t being used, but it’s good enough for me; if you’re an audiophile, you shouldn’t be listening to anything through built-in laptop speakers anyway. The graphics fix I detailed in this post, so I’ll share the fix I found for the soundcard. It’s fairly simple; in a terminal, run

where soundfix.conf can be named anything you want, and then paste these three lines:

alias snd-card-0 snd-hda-intel
alias snd-slot-0 snd-hda-intel
options snd-hda-intel model=targa-dig

into the file. Reboot and you should have sound that doesn’t all come out of the bass speakers. If you want, you can replace targa-dig with one of the other models listed under the ALC888 section here; if one of them works better, let me know in the comments and I’ll edit it in.