I have been thinking about building a sub for a while and currently was looking at dual 12's instead of the Tempest I originally though about. The Peerless interested me a lot. I cant find exact measurements, but fromthe passive radiator, I gather it has a one way xmax of 24mm. I believ the Shivas is 16mm? I saw the peerless at madisound for $145 I believe, and from the specs it looks like it would require a smaller box than the shiva to get a low Q. Im planning on a Q between .577 and .60. I am having a hard time understanding the spec sheet at the peerless sight. I would like to use 2 of those peerless 12s if I could keep the box reasonable small. Could some one tell me more about this driver? Also if I am correct about the Xmax, price etc.?