I've not read every post in this thread, but I haven't seen this "solution" mentioned: press the headphones against your head!
There clearly are software issues as well (what people described above, fixed with switching camera on/off), but I noticed that when I use the headphones to play music through non-VR means (i.e. youtube), I only hear bass when I press the headphones against my ears. Maybe other people have much wider heads (unlikely, as I can use the normal head cushion) or their headsets have much stronger springs on the earphones, but if I wear my Vive Pro the headphones touch the ears only very lightly and this kills everything beneath ~150Hz or so.
IOW no matter what happens to the software, the headphones are completely inadequate at least for my size of head.
