Lovely build and awesome bracing, Nick!
This build inspired me to pick up 2x SB Audience NERO-21SW1100D to accompany the 2x B&C 21SW152-8 in 19 cu ft LLT subs that I already have. I’ll discard these LLT enclosures as they’re simply too large and can’t be moved for better room response. I still have a nasty dip at 40Hz so the plan is to build 4x new 7 cu ft sealed enclosures so I can play with their placement to get the best possible response in all listening positions before DSP.
BTW do you use filters in WinISD? I usually add a 4th order 80Hz Linkwitz Riley to get an idea of the intended (subwoofer) use. These filters (present in power amp of AVR) also seem to influence GD what can be of importance when you want to integrate more subs in one room.
Keep up the good work 😉
Frank