I had a similar problem with my Martin-Logan CLS II speakers. I purchased an electronic (active) crossover from Paradigm. It's a model X-30 and sits between your pre-amp and amp. You set the frequency for what goes to the sub and pick either 50, 80 or 120 Hz hi pass that goes to the power amp and your main speakers. There are several other companies making similar devices. It works quite well in keeping the low base away from the panels.
