Hi all, I happen to have 2 tempests that need an enclosure. I also have a 250 watt plate amp. I'm very interested in the thought of a sonosub, and can get sonotube rather cheap in my area. I of course want tight bass for music, and loud low bass for HT. I was thinking of building 2 sonosubs, and putting one in each corner. The enclosure would be a 20" diameter 48" high peice of sonotube. That yeilds just a little below 250 liters. I would then tune them to 12 Hz. I only want them to play from about 60-70 Hz down. They'd be about 12' away from each other. I'm planning on tuning them that low, and with that size, because that's what size a sealed enclosure with a QTC of .6 would have. (I could easily plug the port, making it sealed if I wasn't happy with the vented config) Also, with it tuned so long, it has a really nice smooth roll off, and an F3 of 25 Hz or so. Plus, with it tuned so long, excursion is much reduced, compared to tuning it to 20 Hz. (Also, during movies with extreme low freqs, I don't have to worry about cone movement below the tuning of the sub, I don't expect there'd be to much info below 12 Hz) Any significant problems anyone can spot? Will that provide me with tight 'feel it in your chest' bass? Will I require any polyfill, and if so, how much? As for the weak amp, I plan on getting a QSC RMX1450 power amp. That'd provide them with 450 watts each (into 4 ohms) or if I needed/wanted more, I could bridge it which would produce 1,400 watts into 4 ohms (I'd just have to use one voice coil of each sub then) Would that make a nice sub amp? I'd just have to wire my RCA plug into an XLR (supposed to be very very easy, I'm not worried about that at all) One thing I am worried about, is, will the voltage/impedance from the RCA output of the reciever (Nad T752) be 'good' enough for the XLR inputs of the pro amp? I know some people have issues using RCA's because the voltage of the outputs on receivers is so low compared to what the inputs of pro gear expect.