Your car radio is original and you want to install a subwoofer.
The solutions
Here are some tips for connecting a Hi/low box to convert the audio signal output from your car stereo into an RCA signal compatible with your amplifier for your subwoofer or speakers:
1. Check the Hi/Low box documentation
• Each model may have specific characteristics. Read the manual carefully for exact connections and possible settings (signal levels, power supply, etc.).
2. Identification of connectors
• Locate the car radio speaker outputs (use a multimeter with an Ohm value to see the speaker resistance).
• Locate the HI/Low box inputs designed to receive the audio signal.
•Be careful if you recover the signal on the right and left speaker, please find the correct polarity (+ -) if a polarity is reversed on the input of the Hi/low box the signal will be Zero at the output.
3. Signal Connections
a. Connect the car stereo audio output wires or cable to the Hi/Low box inputs
b. Make sure the car radio ground (GND) is properly connected to the ground of the HI/low box to avoid interference.
4. Power and Configuration
• Some Hi/low boxes require a +12 volt power supply to operate correctly, we recommend locating a +12 volt after ignition.
• Make the adjustments indicated in the documentation (e.g., impedance simulation for multiplexed vehicles or signal level).
5. RCA / REMOTE output
•You will usually find a blue cable which is used to start the amplifier once the Hi/low box detects an Audio signal
• Once the signal is converted, the Hi/low box offers one or more RCA outputs.
• Connect these RCA connectors to the input of the destination device (amplifier, recorder, etc.).
• Be sure to use shielded RCA cables to minimize noise.
6. Final checks
• Test the setup with a test signal to ensure the sound is clean and the signal level is correct.
• If there is a problem (parasitic noise, insufficient volume, etc.), check the connections and settings of the box.
In summary, connect your car stereo's audio output to the Halo box's inputs, ensure a good 12v power supply, then use the box's RCA and remount outputs to connect to your amplifier. Don't forget to consult your Hi/Low box's manual.