To anyone who has a crackling/buzzing speaker on their #anbernicrg35xxsp check the contacts for the speaker on the mainboard, there was what looked like thermal compound dried to one of them (probably happened during assembly) that was causing mine to buzz and crackle even at 0% volume.
After cleaning contacts with 70% isopropyl alcohol the speaker no longer buzzes or crackles (except a small pop or two during re/booting, which is probably just due the type of speaker).
I hope I saved someone else a lengthy RMA request.
