m-db
To be fair the most expensive and finely crafted British made Studio III was the oldest sub in the comparison.
I have considered adding a second Storm 3. However, the price they want is near to what I can buy a new SVS. And, the Storm is now 12-15 yrs old. IOW, its old and ready for service or retirement soon. So I am hesitant. However the storm does integrate very naturally. And I use the high level input as per Rel's advice.
Kennythekey
To deal with a specific issue of lost bass energy due to a large room with open front wall corners, I purchased a pair of semi - DIY GR Research/Rythmik open baffle subs.
Rythmik is one of the contenders in my search. I am a woodworker so the DIY kits are interesting. My only question is whether a kit will be cheaper? IOW, if you count your labor as worth something, can you really save any $$$ over a comparable production Rythmik sub? Often this is not the case unless you don't count your time and labor in the equation.
Oteekeekid. I read one user review on AVS forum which put the SVS SB 13 against the Rythmik E15 (?). The E15 was more nuanced and detailed than the SB13. The SB13 was no slouch and was considered extremely close in its bass quality
Thanks for your responses