we'll use his head unit front/rear outputs to feed channels A and C, respectively. HU sub out will go to the sub amp. Channel B gets the same signal as Channel A (via switch). Channel B Inputs/Outputs are not used. Tweeters to Channel A, Midrange to Channel B.
we will use a high pass crossover on the HU rear outputs in conjunction with the low pass on the Audison Channel C to achieve bandpass for midbass.
i'll be helping him with amp setup and wiring (remotely). i've helped other people with Audison amp setups/tuning in the past. they can be daunting to some, but i look at diagrams above with a smile. i love knowing what's going on. i love LRx amps.