Hi guys, its been a long time, moving round the country and such. I ran the gamut from sda's all the way to quad esl's and now i am back to the rti series, mostly because of my constant movement. Recently my last trip i ruined two rt35i's and on rt55i. Instead of repairing them (out of luck since polk does not have anymore rt35i cabinets) I was thinking about making a tower of power subwoofer. I figure if 2 rt55i woofers in a vented solution can get to 40, adding two more in series might be able to lower that figure into the 30ish area, sort of the way the old sda's generated bass. The problem is that i do not have any info on the woofers (F3, vas, etc) and polk support is closed. I would like to start on this project this weekend, and any help would be appreciated, if not, I guess its trial and error...good thing mdf is cheap, and i have a full weekend to mess around with simple boxes.