I did it quite simply, andf only used 2 channels of input to the amp.

I have Dynaudio MK242 components, Kenwood DNX 8120, and an Image Dynamics Q 450.4 amplifier. The amp has a bandpass crossover on channels 1-2 which I used to power the mids, then the tweeters are powered with the remaining 2 channels and adjusted via the on board DSP in the Kenwood.(which doesnt take much even for being on axis to me, still sound great.) I time correct for the mids and adjust the tweeter volume accordingly.
This is my first time running active setup in my own car and it takes some more screwing around to get it right but when it is right it is the way to go.

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Perfect Tones
Custom Car Audio And Security
Milton, Ontario
905-878-9956