I have the SVS PB12Plus/2, but want to try my hand at a DIY sub. Would a Tempest or Tumult equipped sub get me the flat-to-16hz extension that I'm getting now? I'll use whatever power is needed, but don't want to go any bigger than the SVS enclosure if possible. I also do not need ANY more SPL than the SVS. It's more than plenty. I've read that the Tempest actually has better extension than the Tumult. True? Any suggestions?