I realize the thread was more of a Dyna tech type question, but it's evolved into a bit more and for the sake of others who are curious I just wanted to update.
Anyway, it seems that after several times of using this, the speakers seemed to get louder. Not so much that it's night and day, but they seemed to "loosen up" and have fuller sound. I'm overall pretty pleased considering the reality of the fact I have very loud mufflers and major wind noise for not having a windshield and fairing.
I do love being able to listen to the music though, so it's a success in that area. I'm thinking of adding the Boom tank pouch too. I'm happy with the thumb controls too and they fit right in with my stock controls' styling. And, this may be sacrireligious in the Harley world, but I'm even considering putting my stock mufflers back on (well, one stock muffler, and getting a replacement take-off to replace the catalytic converter that takes the place of a seconds stock muffler... silly California, but that's a different subject.)
So, if the goal is to have some music, it fits the bill, but you do have to have realistic expectations. :s
I must say... it feels so good rolling down the road listening to "They call me the breeze..."