Here's a little about the unit!
AUDIO INPUTS
Many factory-installed systems include on-board equalization and crossovers that make simple connection of aftermarket products difficult. The MS-8 includes the signal-summing circuitry, signal-conditioning EQ and time-correction processing that are necessary to reconstruct a flat, full-range, two-channel signal when you use the MS-8 with factory-installed equipment. Aftermarket head units with line outputs provide a flat, full-range, two-channel signal on their front line outputs, so you need to connect only those channels to the MS-8.
Connecting an aftermarket head unit If you’re using the MS-8 with an aftermarket head unit that has RCA-type outputs, connect the head unit’s front left and front right outputs to the MS-8’s line inputs 1 and 2 only. Do NOT connect any other head-unit output signals to the MS-8’s line inputs 3 – 8. During the calibration/setup process, the MS-8 will “normalize” the input signals and derive as many output signals as your speaker system requires.
