Can you play with the crossover frequency of the sub towers? maybe moving it up a bit in frequency would help if you can do that? I crossed my BGs at 300 Hz because I found that preferrable to 200hz from a fullness perspective. I also tried 500 Hz but then I lost a significant amount of clarity and went back to 300.
The crossover frequency is not adjustable.
The Q of the crossover frequency has three settings. I am using the softest slope (lowest Q) setting.