i'm basically agreeing: > If I remember correctly, the bluetooth headset profile (if you require microphone input) is pretty low bandwidth (think gsm quality),

i'm basically agreeing: > If I remember correctly, the bluetooth headset profile (if you require microphone input) is pretty low bandwidth (think gsm quality), which would explain low quality in that case. the headset profile is a bit nicer than GSM (higher rates, more advanced codec), though nothing you'd want to listen to music through. > Newer Bluetooth variants support higher quality audio without a microphone (A2DP), and that's what you are likely using today unless you are in a call. A2DP has been around for awhile. as some other comments mention, there are multiple codecs that can be used. the minimum one is SBC (also used by HSP, at lower rates), which... isn't great. once you're using aptX/AAC, perceived quality is far more likely to be dominated by the electrical and acoustic aspects of your headphones.