Looking for a two sub set up for a large area in my basement with tile floors. The room is large with approx. 12K if cuft. Would diy give me best bang for buck? If so, what sub and amp? Also, is there any tuner that will help. I will use mainly for music but also with theater. I have 9 B&W speaker (2 sets cm-8s and two set in ceiling + center) powered by Yamaha RX-A3070 ,amp. I like the sealed sound of subwoofers more but in room this size not sure if ported would be better. I would like a smaller enclosure to put under window. I have a RCA subwoofer cable that was ran behind dry wall that I would like to use to supply signal, unless a better way is recommend. Any suggestions would be great.