But here's more food for thought... If using 4 SVS PB12-NDS's (total of $3100), the system will have even more SPL than a single FW18.3 and do it with the same distortion level and more even room coverage
SVS PB12-NSD Subwoofer Measurements and Analysis — Reviews and News from Audioholics
Perhaps, but which would you rather have, four subs that look just okay spread around your room, along with all of the cables and power cords, or one big sub that looks awesome? I'd rather have one (maybe two if absolutely necessary) big subs. I thought for a bit I'd rather have two little ones, but experience shows me that when it comes to subs the bigger the better.
As for other features, like super-quality appearance, amps, connections, equalization, ease of set-up, remote control, completeness of integration, all of that matters. You can't be #1 with just loudness, even if you say so. For most homes, every sub discussed here is loud even at 20Hz, and since bass is omnidirectional with moderate distortion they sound a lot alike too. There's more to a product than just a couple of parameters. The SVS is a great sub at a reasonable price, but it's not for everyone.
And this silly thread is becoming tiresome quickly.