I have a Victory Cross Country Tour with an excellent stereo, low wind noise, and not overly loud pipes. Up to about 50 mph I can hear the stereo very well while wearing a half-helmet. Above that speed, the wind, bike, and road noise tends to drive up the overall noise making the signal/noise ratio so low that I don't like it. For around town, I use the stereo but anytime I'm going to be going any significant distance - even just an hour at ~55 mph, I will wear my other half-helmet that has a SENA SMH10 bluetooth unit mounted on it with in the ear canal style foam ear buds. On the loudest of bikes, at the higest of speeds, I can hear the music VERY well and VERY clear through these in the ear canal type foam ear buds. These also provide another big advantage which is they block out the road noise which is quite damaging to your hearing over the long-term. I do NOT recommend using a blue tooth unit with the speakers mounted inside a full face helmet. There is just too much noise even in a pretty good full face helmet. I don't know if the road and wind noise is reduced enough in a really expensive full face helmet since I've never tried one out. But for anything below ~$250 full face helmet, they do not block out enough wind/road noise to make the use of BT speakers inside the helmet useful. I would still go with the in the ear canal type foam ear buds.