Yah, just one 10" woofer seems good enough with the Transformers 2 last night, so I think I will be pleased. Now I just need a proper cable to connect both subs at the same time. The Tributaries RCA subwoofer cable that I bought has the Y-split on the wrong end so that the cables after the split are way too short - so the two subs would have to be set back-to-back. Unfortunately I am dealing with a ground loop that I need to fix as well, because when I plug the RCA LFE into the sub I then get a hum through all 5.1 speakers (unless I convert the 3-prong subwoofer power cable to a 2-prong).
My plan is to use them for music a lot as well as for movies. So I also thought it would be fun some day to try the subs in my 2-ch rig. I could use my Apogee mini-DAC feeding its XLR out into each sub, and then feed its single ended output into my Yamaha AV receiver so that the receiver can drive my Polk SDA CRS speakers (I set jumpers so the Apogee's volume control affects all the outputs). This should be fun, as I used to have an MK 15" subwoofer with 250 watts running along with the Polk SDA CRS back in the mid 80's.