Bluetooth/A2DP compatibility: 4.0 VS 2.1?
I've been looking at some inexpensive Bluetooth IEMs to use during training, however, the specs only list BT4.0 + EDR Class 2 as supported; the old smartphone I'm using as a music player only advertises BT2.1, EDR and A2DP support.
From a quick Internet search I got the impression that BT 3.0 and 4.0 added functionality that doesn't affect the A2DP/EDR protocols needed to support stereo BT headphones.
Is this really the case? are the earbuds going to work or not?