Does the iPhone 3Gs use A2DP for music? ...

I recently bought the Sony DRBT100 headset (which so far I really like) and started reading about how it worked and got a little confused (my normal state).

Apparently, blutooth technology works in two ways with these combo phone/music players -- it can play stereo music using one protocol, and then act as a headset using another. Okay, so far so good, and it appears to both play music and act as a headset just fine.

But according to the docs, when it is music player mode (A2DP protocol, I assume) the volume cannot be controlled using the Sony magic volume button. This button only works for volume when the headset is using the headset mode (um, something like AHS?) And, it further states, you do NOT want to play music in this mode (which I am guessing is akin to listening to music over your telephone -- low fidelity and probably not stereo).

However, the Sony volume button DOES work on the iPhone 3Gs when playing music, which leads me to worrying that I'm not hearing music in the higher fidelity mode but rather in headset mode. There doesn't appear to be any way to switch modes on the iPhone itself (as my Sony manual says to do when listening to music) and I'm fairly sure Apple wouldn't make that mistake, but can someone assure me that A2DP protocol is being used when music is played?

---

Orignal From: Does the iPhone 3Gs use A2DP for music? ...