Does the crossover have outputs for the mids and highs? If so, even if they are single-ended, this would be worth trying.
Some of the ARC amplifiers that have allegedly balanced differential inputs really don't do well with single-ended inputs (which indicates a radically poor Common Mode Rejection Ratio spec). This is so profound with some of them that if operated single ended they have lower power and much higher distortion. But if your amp is not one of those types this would be worth trying.
(FWIW our amps behave the same whether the balanced or single-ended input is used.)
Some of the ARC amplifiers that have allegedly balanced differential inputs really don't do well with single-ended inputs (which indicates a radically poor Common Mode Rejection Ratio spec). This is so profound with some of them that if operated single ended they have lower power and much higher distortion. But if your amp is not one of those types this would be worth trying.
(FWIW our amps behave the same whether the balanced or single-ended input is used.)