What is a high level input?
High level inputs means that you are using the speaker wire leads off of the back of the radio instead of using the RCA connections. You can take the speaker wire connections and use them to send the input signal to the amplifier. Most factory radios do not have RCA connections so it is extremely difficult to install any amplifier into your audio system. Amp manufacturers started using high level inputs to allows for easier integration into newer vehicles where so much of their data is controlled from the factory radio.
Option 1: Use a Line Output Converter
You can use high to low converters for the amps to accept high level inputs directly. The best way of doing that is by using a Line Output Converter. This tool is very popular because it connects your radio’s speaker wires and converts the speaker-level signals into a preamp-level signal. This will allow you to use RCA cables that run signals directly to your amplifier.
By using this converter, you will be able to control the signals from different channels in your radio. If you have a high powered radio that is more complex to work with when it comes to signals and conversions, than the Line Output Converter would be your best option.
Option 2: Use Speaker Wire
Another option that you can look into is removing the radio entirely to get access to the factory wiring. Speaker wires are all located behind the factory radio’s system. Factory radio’s wiring harness delivers power to the radio and sends its output directly to the speakers.
When you are able to get to the wires, you’ll have to identify which wires go to their respective speaker. It can get tricky because positive and negative wires are usually the same color. The difference is that positive wires are solid colors and negative wires have the same color but with a stripe of a second color; that is the easiest way to distinguish one from the other.
Once you’ve identified each speaker wire, cut each one. Connect the end coming from the radio plug to a new wire going directly to the amp’s input. Then connect the end going to the speakers to the wire coming from the amp’s output. Our 9-wire speaker cable will make it easier to run the connections. You will need two of these cables; one for the amp’s output and one for its input.