Need help first SQ install. Where to test for distortion

[carbon legend]

I am currently doing my first budget SQ setup. Car is a 2006 Acura RL with factory Bose system.

Equipment list going in the car.

JBL MS-8 DSP

Image Dynamics CSX64 6.5 Components all 4 doors.

Image Dynamics CTX-4 for the rear deck and center channel

Image Dynamics IDQ12d2 V4 single sub in 1.8 cu ft sealed

Alpine MRP-M1000 - Sub

Alpine MRP-F450 - Compnents

Now i have been learning alot about gains and testing for distortion. i did pick up DD1 to test on the fly. Now my main question is for testing the factory head unit for distortion. Would i need to test it from the factory amp or would i need to test it at the MS-8 outputs?

[RooTxBeeR]

I believe you can test it through anything. Just as long as the signal isnt effected by any boostings, or crossovers. When I got my HU's clipping, I did it through my amp, which if I had a eq inline, I probably would have still done it through my amp.

[michigancapri92]

Start from the beginning ... Check the hu see where it distorts and then when you have that figured out go to the next source and gain till that distorts ect.