Soperj003

Hi there, I’ve recently fitted a new pioneer HU, and I have bought some Focal front door speakers aswell as a focal sub and amp. I’ve fitted it all today however when I tried to turn on the HU, only sound came from the rear speakers, which means that it was playing from the factory amp. How do I manage to play music from the aftermarket amp? I would be grateful for any help as this is my first time in upgrading any sound system. Thank you