You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!
Installed 4 channel amp on factory head unit and speakers
I bought an Alpine ktp-445u 4 channel amp today for my 2013 f150 stx supercab. I'v wired it up to my factory head unit to power all of my door speakers. All of the door speakers are stock but I will be upgrading soon probably to Alpine type R. It is amazing how it changed the sound of the stock speakers! Really woke them up but they do need to be replaced.
Last edited by Nayriles89; 08-12-2013 at 10:04 PM.
This is the one that I uses. Alpine makes a 445a and a 445u. The difference is the 445u has built in cross overs and uses RCA inputs to plug into an aftermarket head unit. I decided to go with the 445u.
The RCA connectors are simply your inputs for the individual speakers. There are 4 inputs. One for each speaker. Everything is color coded. I simply took the aftermarket harness that will plug into the factory head unit and spliced the matching speaker inputs together.
You'll have a lot of other wires on each harness that you need to use but not all of them. All you have to do now is splice the matching wires from one harness to the other. Most of them are color coded but you might want to refer back to the papers that come with each harness to confirm the purpose for each wire. After I spliced together all of the wires that I am using, I simply placed wire nuts on all the spares and I was done. I didn't have to do any cutting to the factory wiring harness. This is a complete plug and play. And it sounds awesome!!