You should talk to REL. I ran stereo subs for years, When I stacked the subs,as REL suggests, the result was, by far, the best improvement to the entire system. It doesn't just make more bass. That's not the point. The bass level remains at a comfortable level but the improvement of the quality of the bass and it's effect on the entire spectrum is major. FYI... most bass is in mono anyway so running them in stereo is meaningless.
Once you stack you'll never go back.

