Are big subwoofers viable for 2 channel music?

Thanks miller. Exactly right. Just because the response is smooth at the LP doesn't mean ringing is occurring with long decay times from peaky modes at other locations in the room. Only DBA can fix that.

For all the RF EE's, that like time domain codes modeling electromagnetic cavity modes where highly resonant cavities require sampling long durations of time to get the response right, where as low Q /broadband antennas and cavities can be accurately characterized by a quick impulse. 

What I'd like to know is whether a 4 smaller sub DBA has diminishing returns over dual larger higher powered subs when room correction is employed. I've got a treated room but still have difficulties taming the lowest frequency suck outs from SBIR. One sub is a non-starter but could 2 subs smooth the room response enough that after room correction I'm 90% there.

Understand a smoother response from 4 subs before cal puts less stress on the filtering algorithm, but audio is full of compromises. I've only got a 3-5 dB suckout near 50hz after cal with mains alone.

What about this new Live Dirac Bass Control module with AI optimization for mag/phase on each sub for best room response at the LP and integration with mains? Seems technology could go along ways towards whittling down a 4 sub DBA to a dual setup for a very close level of performance. Catch is it appears Bass Control Module is only available in AVRs where a multichannel dac is needed. 

oops, needed a double negative there .... "doesn’t mean ringing isn’t occurring"

I suspect that having ruler flat bass response in a room may not sound as good as we might expect

Thanks for the sharing Tim. I believe room correction has the benefit of improving the tonality of the rooms bass response at the LP. Of all the speakers and amps that have made their way through my listening room, not one did not benefit from dsp. Music sounded more coherent and live with tighter bass and imaging every time I flipped on the Dirac filter. The mixed phase filters are great, and perhaps they are correcting the speaker crossovers and room all in one.

That being said, dsp is no silver bullet. Can't fix reflection points nor extended decay from a "lumpy" single sub bass response, only DBA appears to do that.

One area of interest include using room correction to help integrate dual subs better after level and phase matching to the mains at the crossover frequency. Another curiousity is seeing if using bass management in my newly acquired Parasound P5 produces better sound by unloading my tube integrated LM508ia from sub 50-80Hz duty driving Tekton DI's and simultaneously reducing the SBIR effect from the mains below 50Hz. That falls into the "to high pass or not" category.

Xovers like the JL CR-1 potentially disturb the pristine signal coming out of really nice preamp, then again, the same is said of dsp. I have neither so I'll dip my toes in the water with the P5 which allows funds for a pair of good subs. 

But if you have a DBA, then when you apply the room correction it'll work a lot better!

Yes, all things being equal, the more subs the merrier.

 I think it’s best that I just accept your claim as fact that room correction/DSP/Dirac have had positive effects on your systems.

Tim - I'm using Dirac live on PC. Sound quality improved a good deal with the SOtM txusb-exp card, RUR, and curious cable feeding a Schiit Gungnir. The W4S dac-2 when paired with Dirac was too sharp/forward and when paired with class D amp - unbearable. Now the sound is more tame. Using 244 panels and tritraps from GIK which helped out mostly above 80 hz.

I've always been a bit skeptical and suppose somehow the dsp is ruining something. When swapping new amps, speakers and preamps, the unique sonic characteristics of new components have always shown through even after calibration. It's not too unlike the DBA decay effect where certain sonic characteristics do not reside with the initial CW signal. Send a CW signal through a system, and each component imparts it's unique harmonics and noise. Speakers especially retain their flavor from inert  to lively cabinets and drivers, both of which will impart higher order harmonics from a CW signal during cal, but it is only the CW signal that is phase and mag corrected at that instance in time. The broadband response to the CW excitation remains and is uncorrected. I'll probably always periodically test feeding the Dirac device and then the dac directly too make sure I'm not leaving something on the table.

The P5 so far sounds as you say, neutral, and likely has a better attenuator than the LM508 integrated. Inevitably it is just a stepping stone. Wanted to spend $3000 on a higher quality preamp but figured the P5 with dual subs for similar price would make more of an impact.