Here is my system
HU alpine cda-9807
amp alpine mrv-f450
crossover options & speakers + sub
channel 1/2 (50, 60, 75, 100, 140, 170, 200 hz) FRONT 6x8" infinity reference
channel 3/4 (50, 60, 75, 100, 140, 170, 200 hz) REAR 5x1/4" infinity reference
channel 5 (30, 45, 60, 85, 110, 140...