I needed some advice on a subwoofer purchase. The sub I was thinking of going with is the Definitive Technology Pro Sub 100TL (cost $416 from a local dealer). I've been reading some good opinions on Audio Review about the Acoustic Research PR1212 (250 W, 12" down-firing with 12" passive front firing, cost $288 on-line) and the Audio source SW12 or 15 (cost $149 and $199, respectively on-line). I have Athena AS-F1 floor-standings for fronts, Athena AS-B1 rears and a AS-C1 center powered by an Onkyo TX-SR800 receiver. The As-F1's produce very good bass for music. My listening room is 12x18. I'm looking for a sub for both music and HT. Any advice on the above subs are any other suggestions would be helpful. I don't want to spend more than $400 to $450, but if I can save some money that would be great to.