WildThang ,,,,,
I don't know ,, I was at the bikefest in Vegas, standing out by the J&M demo trailer, demonstrating the new J&M 7.25's right along with our guys ,,,
they are not only MUCH louder than stock but have a MUCH wider frequency range, more bass and highs ,,, now maybe my ears are old and fat along with the rest of me now, but the difference is night and day and no, you don't need an amp ,,,,
wish you all could have seen the joy on the 15 or so riders faces of the bikes we installed the speakers into, as they rode away from our trailer ,,,,
they work, the performance difference is real ,,,,
those who now pooh pooh them either have ears different than mine or other reasons ,,,
don't know what else to say ,,,,