Have you tried Dirac Live? Particularly with a receiver that supports their Bass Control feature? My NAD receiver only supports regular Dirac Live and it's still much, much better than any integrated room correction from Denon/Marantz, Yamaha & Co.

The improvement is so noticeable that I assume it would take a lot of resources to fix the room physically in order to achieve similar results.

I don't want to sound to enthusiastic but I'm pretty certain I'll never buy a receiver that doesn't support Dirac Live.