What you could try is change the speaker settings for front/rear, so the cross-over changes. If you have small speakers, you can select larger Belolabs, so less bass is sent to the sub. Vice versa if you choose smaller Beolabs, then more bass is sent to the sub. If your speakers are in the list then the settings should be optimal for your combination.
I have a similar setup and I did use a sound pressure meter and the speaker tests from THX DVD to optimise the sub integration. In my case the sub was too dominant and I adjusted with a setting of -6. Since then I am very happy with the setup.
Cheers,
Frank