Axiom Home Page Forums General Discussion Advice from Axiom Owners What to do??

If Large/Plus sounds the best, then keep it there. The position of the woofers have a definite effect on where the standing waves built up, or get nullified. With only the EP175 producing bass you may be sitting in a null. Two more sources help even out the response.

In my case enabling Plus caused a null at my listening position.

Have you run the MCACC 3-position standing wave attenuation? That helped even bass response even more.