DD-1 help with JL Audio cleansweep

[Nubz7twenty]

I'm installing a system in my girlfriends car and I'm using the cleansweep. Ok now what I was wondering is to use the DD-1 on the cleansweep ,do I use the DD-1 on the factory speaker outputs to set the volume for non clipping. Then once I establish that ,then hook the clean sweep up and set volume on factory headunit flat and to the non clipping volume. Turn up the cleansweep till I have a clipped signal then back it off one for non clipped since it doesn't have adjustable gain except on aux. Then mark both the cleansweep and factory headunit volumes at max non clipped volumes and tune amps from there .