Not musical? and your experience with this is?
Pete replaced the avalanches with the SS. Yes that system has been replaced with 4 15" destroyers that are according to Pete also on the way out.
I have heard the SS in a simple ported enclosure run off of a MA audio 4k amp. The enclosure was tuned a little higher than I care for at about 38, but still had very good output down into the 20s. Can't tell you a meter score.
Pete's wall is a rear loaded horn that does not have an exact tuning freq. I can't personally vouch for his sound quality, but there have been plenty of others who can.