First, I was going to (try and) mount the whole original headphone, but its just too big, and on my current helmet they need to go very close to the strap, so there is just no room. I found that the inner lining is only held in by velcro. So, it was really easy to remove just the bit I needed. Cut a slot and used some long nose pliers (Leatherman of course) to pick out a little of the foam.

So here they are in, and what the MP3 'remote' looks like. I intend to simply extend the buttons from the remote to a box with a few switches on the bike somewhere.....more on that as we get to it. For now, the speakers sound great. The FM transmitter has been ordered, we have to get the speakers in the helmet proper and get a connector on the helmet so we don't have a lead hanging off it all the time. (Yes, just so we are clear, first, the music, then the microphone!)