That’s a wonderful offer! Unfortunately, I no longer have a way to play CDs up there. I’m streaming, vinyl and NAS. Fortunately, i was able to get some sense of all this after finding test tones on Qobuz. 50 hz down is problematic. Above 60 - no problem. A test CD certainly would have made it easier though.
Noted on the model being directionally correct. Thank you for the additional explanatory detail.
It does give me some starting points. I will note that my proof of concept test with my old small sub worked best in the current speaker configuration (along the 23’ side wall) with the sub just to the side of the mains and in relative phase alignment. That gave me hope that it may not be too difficult to achieve good results with two of them positioned similarly. But, there may be even better positions for two so I’ll refer to your model when I get them up there. That may take a couple of weeks.
Still looking for user feedback on Perlisten and/or SF Gravis. REL remains the easy and most likely choice.
As a side note - I understand why many suggest DSP as necessary or at least desirable - particularly when dealing with complexities of integration, phase and equalization of subs to large full range speakers. My suspicion is you’re correct - this might be a great application for DSP. But, I also tried using DSP (via DIRAC) in a different system and room several years ago as I wanted to see what might be achieved. The results of that test scared me away from DSP. Perhaps it was user error but I found the correction so harmful as to be unlistenable. Hence my skepticism and bias in favor of RELs approach. But, I’m still learning here so I welcome the input.