nvm, I reread the post and if anything, the construction might lead to a room that's maybe bass shy and strident. One thing you can check is to run the mains in Direct mode. That bypasses any internal crossovers and sound processing circuitry, and will disable any connected subs. If it still sounds off, it might just be a room issue that needs to be tinkered with.

Author of "Status 101: How To Keep Up In A World That Keeps Score While Buying Into Buying Less"