We are mounting a radio to our bike - in fact it is on.
We are using external speakers mounted behind the windshield.
We have STOCK PIPES on the bike so noise from the pipes is a non issue.
The radio puts out only 8 watts - but I feel the manufacturer was consrvative in those figures.
I tried ear buds, but found them a bit distracting.
At least with external speakers I can still hear all that is around me and volume control is near my left thumb.
Nothing like cruising around listening to a ball game on the bike!
We have AM/FM , Weather Radio , Two Way Radio, Rider/Passenger Intercom ( requires head phone/mic but we listen to radio and if one talks the radio goes quiet ), External AF input for iPod, GPS, anything!