I'd think if you are getting good response at your seat, and only your seat matters, you're likely fine as is. A full listing of gear involved may not be necessary, but could be interesting. I wouldn't expect different "imaging" from another sub in any case.
Hi
Was hesitating on posting more info, here is the system. Sorry for the wip.
The receiver is a Yamaha Aventage a4a
The mains are in an Open baffle. This includes the bass drivers.
This powers the wide band SP 15 A (15") 103 db efficiency with a modified re cone job.
Fountek Neopro10i Ribbon Tweeter 102 db powered by a Plinius 8200 MKII that is crossover at 4k with an active BRYSTON Xover.
The Supravox 15 " 400 exc. (98 db efficiency) This driver is powered by its own analog power supply (I posted a photo of the HP) (Set at 5 volts)and a Paradigm X30. I do not use the xover in the Paradigm amp, but again the Bryston Active Xover. Cut off at 150 hz, Gain + 6db. The FS of the Supravox is 23 hz. The magic in this driver is the QTS being 0.7 at 5 volts, so it works very nicely in an Open baffle.
I will post my FR in REW soon as soon as I get it up and running again.
I won't mention the surrounds (which are also ElectroVoice in an Open baffle ) right now as I am trying to stay on topic with the 2 channel setup.
To this I have an SVS PB1000 cut at 33hz @ 24 db / octave