Im going to add a sub to the factory head unit. Is there an adapter i can buy that will add RCA's and a Accessory power, or do i need to splice in to the door speakers and add a LOC? I drive a 2015 jeep patriot sport with the stock 3 speaker sound system
Tapping into factory head units has become much more effective in terms of adding RCA's or remote turn on leads for aftermarket components. Recently I was looking into adding a sub and amp to a friend's car with a factory radio and did some research on what it would take and came up with a good solution that is relatively affordable at about $70. AudioControl makes a line-out converter that should do what you are asking for. There are other and more inexpensive options that can give your RCA signal out from a factory unit, but this is option may be ideal for you.
From their site: The LC2i, is a compact, two-channel processor with active input circuitry, which allows it to accept speaker-level signals of up to 400 watts per channel from factory-installed source units or amplifiers. It converts them to high-quality pre-amp signals that can then be directed to after-market processors and/or amplifiers. Users can enjoy maximum sound quality while maintaining the use of factory volume and steering wheel controls.
To clarify a bit...
This unit does require a power and ground to work, but it accepts speaker-level inputs from basic factory radios or "premium amplified" like the Patriot's option for Boston Acoustics up to 400 watts from the factory amp. So that means adding onto even a premium factory radio isn't really a big deal anymore. This adapter also has controls to "clean-up" the speaker level signal for tuning it accurately for bass/sound as it has 3 adjustable knobs, one for bass roll off, one for a bass boost, and one for an overall input sensitivity or gain. This adapter gives you 2 choices for signal output, either "MAIN" output used for an amp for mids or highs, or there is a "BASS" output used for subs. And one of the best parts for a LOC feature - The LC2i has GTO Signal Sensing, which will turn the unit on when it detects signal at the input from your factory amp/powered head unit. So if you feed it speaker wires, it will send a remote turn-on signal to your aftermarket amp when it detects a voltage change from the factory radio.
If you install this unit near your aftermarket amp and run speaker wire leads from the rear door speakers, you can tap into the new amps power and ground and that's all you need for this lil guy. It's not a bad deal considering the cleaned up signal, ability to handle high power input signals, and built in remote turn-on.
Hi....you’re going to have to disable/unplug your ANC (Active Noise Canceling) module with a sub install. This can be found under your factory radio...behind and above the storage pocket under the A/C controls. Second, no RCAs are located behind your factory radio, so an LOC will be required. And last, but not least, you have to pull the right speaker signals from the factory harness when wiring in your LOC.