Currently I have my one SBB4 Tempest. I don't think I will be able to upgrade the main speakers of my HT because it would require a complete overall(which I can't currently afford). ie: If I upgrade my Titans to Studio 20s the timbre match would be terrible so I would have to upgrade all speakers. So anyway heres the plan. Thinking of building a sealed sub for music mostly. But I would also play it for movies for the extra output. Here are my questions: 1) I've heard that corner loading two subs will give you 6dB more than a single. Does this only apply to identical subs/enclosures or will I still get a 6dB boost by having a sealed Tempest join my SBB4 in the corner? 2) I may be able to get a small dedicated HT room in the loft of our garage:b ) An IB sub would be a real possibility. How would a dual Tempest IB setup compare to that two above models combined? 3) If I went IB could I keep adding more Tempests if budget permits?