Yes I read through this post and various other sub-woofer threads for last few days and gained some knowledge.First, have you read through this lengthy but excellent post?
The Guide, which starts here in Post 1, and which continues in Post 2, is intended to be a general guide to Home Theater, HT calibration, and audio quality. Due to its length, I have had to divide it into two posts. Sections I through III follow the Introduction in this post. Sections IV through...www.avsforum.com
Second, it sounds like your calibration is maxed out since it is -12. That thread talks about getting the best calibration. It also means you will probably have even less bass at your start.
Did you buy directly from SVS? You can return that sub and just go larger (and that should increase your budget). Based on my reading, many here will tell you to buy the single largest sub you can affortd to buy if you aren't going dual to eliminate nulls and smooth your frequency response. Mixing the different sized subs isn't going to be preferential, either. You are going to have two subs with different output levels and frequency responses and may create even more problems for yourself without some extra work.
I get the size preference, but I'm also not sure you need a sealed unit simply because it is mostly music. And there is also the option of the PC units if you want a smaller footprint with ported.
Sure others will chime in. Hopefully @Ed Mullen will respond. I'd call SVS as well, but I think at a minimum you need two of the 3000 series or one of the 4000 series based on what you are looking to achieve in that size of a room.
I bought from Amazon and cannot return it now. Based on output I am getting from sb-2000 it looks like I will do well with dual sb-3000, and it may better than single SB 4000 but I was thinking of re using sb-2000 with the new sb-3000 if it makes sense. I don't want to go with the PC models for whatever reasons. When I called SVS they commanded dual SB16 ultras which is beyond my budget, probably because I told them I listen to high volume music which may not be entirely the case.
I think the same like you that 2 of sb-3000 would be best for me, I have read that single sb-4000 creates highs and nulls and dual sb-3000 do better than single 4000.
My idea was to reuse sb-2000 that I already have with a new sb-3000 if that would work as well. That will save me about $500 if I buy 2 new sb-3000 instead and sell sb-2000.