The ICBM and SMS-1 address somewhat different issues - the ICBM provides bass management (adjustable crossovers for center, mains, surrounds, and rear surround) for up to six channels, while the SMS-1 provides somewhat different bass management for two channels (fixed 80Hz crossover for mains, separate adjustable crossover for subwoofer) and equalization. In a two-channel system, the combination is probably unnecessary, but in a surround system there are still cases where both units would be able to contribute effectively.