I'm not a construction expert, but I'd think having studs 8 inches on center would be bad. A standard sheet rock wall gives some amount of bass trapping, especially if the wall has fiberglass insulation inside. It's not great bass trapping, mostly because it's fairly frequency selective. But it's better than nothing and it's free.
If you have studs close together the walls won't be able to flex as much, and in turn will have less absorption. At least I assume this is the case.
--Ethan