I need some advice on whether to get an SVS 20-39. My room is 12 x 12 x 8 (1152 cf). Music 25%, movies 75%. I used an RS meter to measure the volume of what I listen to, and it is usually between 70db to 76db, with some peaks outside that range. At that volume level is is worth the expense to upgrade from a Velo CT-120 to an SVS-20-39? I'm just wondering if I'd have to listen at higher volume levels to hear a big difference between the two subs. Anybody been in a similar situation?