David,

This is a simple matter:

1. Switch the analog BM to 'on'...no double bass. (filters all sats @ 80 Hz and redirects sat's bass @ 80 Hz and below to the sub along with the full LFE signal...best choice)

2. Switch the analog BM 'off' and dial your subwoofer's LP filter to the F3 point of your mains...no double bass. (assumes all sats are 'large', but least desirable choice for various reasons)

3. With either of the above choices, the ICBM is not needed.