under A2DP, aptX, with the worst in the cable Bert drive (!!!) - the worst sounding Bluetooth headset, I could try to date (and there were a few ...). The facilities are good, it is comparatively easy, but it's really not just about the sound? my opinion, yes. Thin heights, weak middle, grumpy, too powerful but completely spongy bass, which then also overrides at higher levels. This is the headset for completely deaf and / or tone-deaf people, this sounds right does nothing - I've never heard such a disjointed, imprecise sound even with cheaply-of headphones. Quite awful.