Hello, I'm gonna upgrade my factory stereo front stage but keeping the hu. I'm thinking of getting the kenwood eXcelon XR-4S amplifier which has decent power and bi amp capability. My budget for 61/2" 2 way component system is $350-$450 but in my search I see that not all of them have a crossover which can be bi amped. Is it worth it to bi amp a passive crossover? If so, can you recommend good speakers that have this capability?