OK, the time to upgrade has come again. Do I buy a Sony STR-DA2ES receiver or an SVS 20-39 CS subwoofer? I currently have a Sony STR-DE475 receiver which is doing the job for now, but is there going to be a sonic difference by changing to the 2ES? ( I have Energy take 5.2 speakers) My subs consist of a Sony SA-WM20 (8 inch 50 watt), and 2 64 liter DIY sealed cubes with two unknown 12" car subs I got off a guy for 50 bucks, powered by a Kenwood 2 channel amp @ 175 watts per channel. I would plan on powering the SVS with this kenwood amp until I find a suitable plate amp. Please! What would YOU do?