I'm running both VBSS's (31 Hz tuned) and sealed Ultimaxes nearfield, with sealed SI HT18's up front.
Of all the iterations, what's worked best for both tactile and subjective sound quality has been to steeply cross over between the VBSS's on the high side, and the sealed subs on the low side. I looked hard at the WinISD sims, and settled on 23 Hz L-R 24 for both high and low passes. The steeper slopes definitely worked better. The sealed also get a 20Hz Q=3.4 6dB boost.
All are leveled and delayed to account for distances to MLP. Subs are crossed to mains in the preprocessor at the usual 80Hz Butterworth 12. Having 1899's for mains doesn't hurt, either.
I tried to integrate them all over the entire bass range, using REW and various approaches, but in the end splitting the duties between ULF and low/mid-bass worked (subjectively) the best. Also made the best use of headroom with my particular setup. And no limiters engaged anywhere.
I have severe limitations on sub placement, obviously if you can move yours then that's a whole different ball game. My goal with the nearfields was to drown the modal response with direct response, and maximize tactile. The four SI's are more to squeeze in a little more pressurization than to even out modes.
I know that's a lot of subjective opinion on the results, but it's a pretty easy by-the-numbers approach to try.
Sources/processing: stack of stuff that if it isn't vintage now, it will be soon!
Amps: stacks and stacks of old iron
Main speakers: big DIYSG
Surrounds: Bose graveyard
Subs: a bunch
Last edited by fill35U; 12-12-2018 at 10:39 AM.