^^don't second guess your purchase. That's a very good sub you bought. Remember on these boards everyone has their preferences and favorites, just because they said it's good doesn't mean you'll like it, or that it's the right speaker for your application.

 

I can't believe the SW8210 is $150 from sonicelextronix when on other sites it's $250-$500. 1.5 cubes minimum sealed. 86 dB sensitivity, the SW8200 was 82 dB. It says 38mm x-max on the Eclipse site, but 28mm on sonic.

 

Consider the Stereo Integrity BM's you could have 2 of them in the space you have!