Depending on the distances, you might get away with it!

The mconfig programme does allow you to setup speakers based on stereo (music) and then differently for movies (2.0 and multichannel). So you could set up music so just your LR speakers play full range and movies where they are set to small with crossover to the sub.

Another option, since you have fairly capable main speakers, and this depends a bit on your preferred movie listening levels, is a tactile transducer which could live under the MLP seats and vibrate them directly. It's surprising just how much scale they bring!


Chris
Srces: Wiim Pro | OSMC Vero 4K+
Procs: HD621 > G61R > Minidsp DDRC-88D
Spkrs: 7200.2 + 5KC + 5Ks | iNuke6K > USC15 | iNuke3K > 2 x Crowson T108SS
Video: JVC HD950 & 1.9m React3 2.4:1 screen
Room: 5.8x2.8m | Various GIK Panels