Thanks, I have not tried this with a SET. Maybe I can hook up my 300B to them someday. If I was going to guess. They should be fine. The original efficiency is maintained and the attenuation is just a preferance. The tube amps usually have problems with woofer impeadance and that should not be a problem in this case. The Box size, tuning and woofer has all been worked out by Wayne and I wouldn't deviate from that. No reason this couldnt work with the 2 Pi tower, it's a larger box with deeper response. For a size inbetween you would have to consult with Wayne.