I used to have a small mic that I just mounted inside my lid. I did have an FX helmet, so yes.. my helmet was very heavy. Amp, static bust n all was in there. Ran out of computer speakers through the areators. Was nice to be all contained inside.. but was a tank.
For my biker, I actually had the amp in a front chest pocket of jumpsuit. The armor covered it, but I could crank it up. I had a long cord that ran up inside the jumpsuit, under a neck protector and I just actually found the best way was to just tape (with that medical style bandaid kinda clear stuff) right to my chin with the small mic facing upward just under my bottom lip. Sounded great. Looked like I had some sort of weird goatee when I took my helmet off, but hey.. keep your lid on. :lol