I have a friend who experimented with ear buds, and custom plugs. He used a very inexpensive set of ear buds. He told me even the cheapies sounded fantastic, when their sound was channeled directly into the ear canal. They also were extremely loud, so he had to really back off on the volume -- the custom plugs blocked out all ambient sound, so the buds did not need to compete with anything.
On long trips, there are numerous times when I would like a simple music solution. This is really tickling my fancy. We may just spend the $10/set, and build some custom ear plugs/buds. The music solutions on our intercom system have never really worked out like we wanted. Thanks for sharing! Cheers!
1979 CB750K (sold, 2012, but not forgotten)
1983 Kawasaki 440 LTD Belt Drive (sold, 2011)
1993 Kawasaki Voyager XII