I don't see how the Aragon could be causing a brightness problem when it is playing on the woofer. Try using just one amp at a time, either one, with the high and low frequency terminals jumpered. If the amps are not matched to each other, that could lead to a tonal imbalance. Bi-amping is not as easy as just using two amps on a speaker, unless the amps are identical or you use something like a dual amp balancer. Don't spend any money on this until you have tried only one of the amps.