Greetings South Park,
First, let me tell you what I think might be happening with the Martin Logans in your room.
Sound propagates differently from a line source than from a point source, and with the hybrid Martins the panels act as a line source, and the woofers as a point source. Sound pressure level literally falls off more slowly with distance from a line source than from a point source. Theoretically, sound pressure level falls off linearly with distance from a line source, and with the square of distance from a point source. Under anechoic conditions, if a line source and a point source are both putting out 90 dB at one meter, then back at 10 meters the line source will be doing 80 dB but the point source will only be doing 70 dB!
What this means is, when a designer seeks to combine a line source panel with a point source woofer, he has to voice the speaker for the general room size he expects the speaker to be used in (or else provide the customer with level controls). If your Martin Logans were in too small a room, the bass level would not have fallen off as much as the designer intended, and the speakers would be bass-heavy.
Now, possibly your room does over-emphasize the bass. If so, it is doing this through bass standing wave modes. You might consider the Gradient Revolution, which uses a rather unique dipole bass loading configuration. For a given on-axis sound pressure level, a dipole bass system will put 5 dB less energy into the room's resonant modes. That means the bass notes will decay more quickly and sound more natural. The Revolution excels at producing very natural-sounding bass in less than ideal rooms.
E-mail me if you'd like a more in-depth discussion. I'll be on the road a lot this week, but will try to check my e-mail a few times. Or you can call me at (504) 866-1730 - that should forward you to my cell phone.