I have a Woofer Tester for drivers in hand, but am trying to develope a crude system for deriving ballpark T/S (Fs,Qts,Vas) parameters from the data given by ceiling speaker makers. For instance: http://www.miscospeakers.com/Upload/pdf/KC620W-B%20Lit.pdf http://www.quamspeakers.com/documents/techspec/QUAM_0201_8C10FECO.pdf Obviously the first has more to work with. Unfortunately the second is more typical.