Today I took a bold step into the unknown and could use any input and help that the forum might provide :o Been looking for some bass units for my Tact setup for months, nothing seemed available from the manufacturers. I needed a bass cab suitable for covering the range from 20hz up to 325hz, all subwoofers seem to be designed to work to 120hz max. I tried the Tact subs, but for my musical tastes, they were a little dry, lightening fast but anaemic. I wanted JBL sound:D . So today I forked out for a couple of JBL 1500AL bass units, the ones found in the new 9800K2 speaker. The TS parameters mean little to an ignoramous like me but are as follows: Qts = 0.27 Qes = 0.28 Qms = 12.84 Fs = 27.3hz Vas = 264.55 l Sd = 880 sq cm Re = 5.4 ohms Mms = 139.59g Bl = 21.64 T*m SPL = 94.7db The intention is to build them into individual ported enclosures, no need for crossovers as the Tact will handle that. Any suggestions for cabinet dimensions, materials, and construction tips would really be apreciated. Regards Michael