bluetooth headphones, how to tell if A2DP is being used

[lazydays]

I had to reinstall osx on my MacPro and now my bluetooth headphones don't sound as good. I'm wondering if somehow I'm using a different bluetooth profile than before. It sounds like mono to me. Any way to tell which profile is in use?

[lazydays]

I found this in the system profiler but it wasn't very enlightening:

DR-BT21G:
Name: DR-BT21G
Address: 00-1d-ba-29-46-7e
Type: Handsfree
Services: Headset, Hands-Free unit
Paired: Yes
Favorite: Yes
Connected: No
Manufacturer: Cambridge Silicon Radio ($3, $d55)

[lazydays]

I removed the headphones from the bluetooth system preference and then added them back. I went to the sound preference to connect to the headphones and noticed there were two entries. One for "headset" and one for "headphones." Selecting the second improved the sound considerably. It was probably there to begin with and I missed it.

[RAMd®d]

The headset setting may have been for an earphone/mic combo and could have either tailored the frequency response or just fed a mono signal to the earphones.