Looking at 6-8 cu. ft. ported box and using the 15" Dayton Quatro woofer: http://www.partsexpress.com/pe/pshow...60&ctab=1#Tabs Yes, I could get a bigger, badder woofer, but then it would require a bigger, badder amp, and it would just get out of control. WinISD shows that in the box I am looking at, I would be getting a solid 20 Hz. at -3 dB - and 15 Hz. at -10 dB. With 300 watts of input, over 110, almost 115 dB. of output. I am considering making it passive, and getting a inexpensive pro amp (under $300) and trying it like that (use my receiver for the crossover) and getting a BFD if need be. Am I missing anything? Looks like it would be a absolute monster. I think having a moderate 15" woofer in a large ported box would allow it to do its job easily and without a lot of distortion - as well as being efficent. Any input would be appreciated!