Hi Bob,
If possible can you explain to me why the JL CR-1Crossover is critical. It costs $3000 which is a lot for my budget.The CR-1 crossover cost is based upon the audiophile grade components used in its construction. I'm not a home theatre guy but I don't think that an external crossover will work with your Anthem. Ideally you would connect your preamp outputs to the crossover inputs and the crossover outputs to your sub amps and main speaker amps inputs. I don't think this connection is possible with the Anthem. You will be fine using the crossover built into your Anthem.