This is almost certainly just a me thing, but just in case: I got some Bluetooth headphones that seemed to sound terrible wired, but it turned out to that the c

This is almost certainly just a me thing, but just in case: I got some Bluetooth headphones that seemed to sound terrible wired, but it turned out to that the cable had to be pushed and rotated to lock into the headphones at that end. If you really mean atrocious atrocious (and especially if it’s Sennheiser HD 4.40 BT), this might be it?