Thanks for the advice. I spent a lot of time listening to kick drum-heavy tracks, also the 1812 Overture recorded with real canons, and ended up at 0 delay as the best setting on the Rythmic amp.
Have used LOTS. Unfortunately I have a very irregularly shaped room with cathedral ceilings and gable windows on one side, so I not only have to experiment with forward and back but also closer together and farther apart. Finally have the NX-Oticas and the OB sub located where the magic happens.
This may be heresy, but I think my setup sounds better than Danny's with the NX-Tremes and double OB subs. One major tweak, I switched back to my 30-year old Gryphon speaker cables (gold-plated silver ribbons) and that added a LOT of transparency and detail that was lost with Danny's speaker cables. However, the Gryphon cables were about $200/foot 30 years ago!
My setup is now THE best stereo I've ever heard anywhere including 5 years of going to the CES High End Show. Even music that I love that was miserably engineered (Cream Disreali Gears original LP) sounds pretty darned good now. I want to listen to everything in my music collection over all over again with this rig! The canons on the 1812 Overture knock you back in your listening chair. You can watch the servo sub drivers go crazy with every shot.
Anybody in the DFW area is welcome to come judge for themselves.
Hats off to Danny on the design of the NX-Oticas and the OB subs! They are killers.