I am adding an Alpine PDX-9 5channel amp along with replacing the speakers. I plan to keep my factory radio. My question is what kind of LOC will I need to connect the amp and radio. Thanks
depends on the vehicle. if you have a multi-speaker premium system with separate amp channels for each speaker, you either need a summing LOC or you want to intercept before the factory amp.
we need vehicle make/model/year/trim and audio system info