I bought the SVS PB10 2 months ago, small room, great sound. Very large cabinet for a 10" woofer. I was surprised by the large size.
I can't imagine the 13".
Seriously, why?
I bet your dad didn't realize how large the cabinet would be, when he told you to pick it out.
I guess that's the problem with SVS - online only (unless you're in Canada). Can't see it before you buy it.
That Ultra series gets great reviews.
Next step...dual subs.