I have KBCs and have speakers (Sony) installed in both. I use a RIO MP3 player and it works just fine, even with the shield up at around 40 MPH. I agree with Yamahor, the music is for the background, I still like to hear whats around me. When I am riding with others we like to talk back and forth, so I have the RIO mounted on the tank bag so I can reach down and pause whenever needed. I think it cost me $20 for headphones and $60 for the RIO? That was a couple of years ago.