I would suggest ensuring that that volume is turned up in call, by pressing the "Vol+" button on the iPhone. After ensuring that volume is turned all the way up, turn the volume up on the RF-MAB2 by repeatedly pressing the "Vol+" button on the headset. If you are continuing to experience low volume levels, I would suggest contacting Apple to establish if there is any other way to increase the in call volume level.
The first time you use the phone you have to selectt the RF-MAB2 as your audio source. After that it remembers. Everything is working great. I love the ability to use voice sommands and to answer my phone from the headset while I listen to my music.
