How To Connect RCA Cables to Car Speakers


If you want to connect your car speakers to your car stereo using RCA cables, you’re in luck because the process is straightforward. All you will need are the cables and an amplifier. 

Here is how to connect RCA cables to car speakers using an amplifier:

  1. Connect the car amplifier.
  2. Connect the speaker wires to the amp.
  3. Connect the speaker wires to the car speakers.
  4. Check the wiring and test the speakers.

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In this article, I’ll explain how to wire your car speakers to your car amp and stereo so that you can enjoy your favorite music while on family and business trips.

Connect the Car Amplifier

The first step is to connect a car amplifier to your car. In many cases, the amplifier is required because the direct signal from the stereo to the speakers will be too weak. 

Tip: If you already have an amp in place, proceed to the next step.

But if you don’t have an amp and searching for a good one, I recommend a four-channel BOSS PF1800. It is a fantastic amplifier for the speakers because it is built in the A/B class.

If you are also looking for wires to the amplifier, use the BOSS KIT2, including all cables you will need for the installation.

There are some variations on connecting the car amplifier, but basic instructions are as follow:

Locate the best place to Install the amp.

You can put it anywhere you wish, but the trunk or the passenger side normally works best.

Connect a power cable to the positive battery terminal and your amp.

Even if your amp has a fuse, I strongly recommend that you use an in-line fuse holder such as the InstallGear (available on Amazon.com). An additional fuse protects the circuit from shorting.

Connect the ground wire to the amp.

The ground wire has to be attached to the car’s chassis. You can use the Acouto Grounding Kit for this, but if your power wire is thicker, the grounding wire should have the same gauge.

Connect the remote cable and RCA cables from your stereo to the amp.

If your stereo doesn’t use RCA cables, use the SCOSCHE LOC2SL Line Output Converter to convert the stereo’s wires to RCA.

Once the amp is connected, you’re ready to plug the speaker wires into the amp.

Connect the Speaker Wires to the Amp

If you’re using the Boss kit, you need to unscrew the speaker output screws, put in the 8 gauge wires, and screw the screws back in.

With most other amps, the procedure is pretty much the same. Just check the specs to confirm you’re using the correct gauge wires for your speakers and amp.

Check manufacturer specs for the recommended wire gauge for the speaker.

If you’re using stock car speakers that already have wiring, you can use them instead. Just remember that the cables most likely won’t be long enough to reach your amp, so you’ll still need to extend the wires.

The easiest way to extend the wires is to splice them together. For a refresher on splicing wires, this wikiHow video offers an excellent guide that explains how to splice using several methods, so follow it step-by-step if you don’t know how to do it already.

Connect the Speaker Wires to the Car Speakers

Now that the speaker wires are in the amp, it’s time to connect them to the car speakers.

You can connect speakers in 3 ways depending on their characteristics and on the type of amplifier you use:

  • in series
  • in parallel
  • or a combination, where you connect sets of series in parallel.

Most speakers use standard spade connectors, which come with many amp kits. If you don’t have the connectors, I recommend Fixitok splice connectors.

Once everything is in place, you’re reading to connect the wires to the car speakers.

  • First, take the speaker wires from the amp and determine which one is positive and negative. This step is crucial because you cannot rely on the wires’ color for this information.
  • Next, take the negative wire and feed it into the negative splice connector. It’s usually the smaller one in almost all cars.
  • Repeat the step for the larger, positive connector and secure the connection using pliers.
  • Now you plug the connectors into the corresponding ports on the car speakers.

Check the Wiring and Test the Speakers

  • Before you test the speakers, make sure you did everything correctly by double-checking your wiring. 
  • Begin your checks by making sure that everything is nice and tight so that it won’t loosen when the car is in motion.
  • Then, pay careful attention to the battery and the wiring around it. If something goes wrong there, it can quickly turn into a fire hazard.

After you verify that everything looks good, start the car.

If your amp has an LED light, check it to ensure it’s powered on and working correctly.

  • Next, turn the stereo on and play some music on low volume. Then go to your amp and fine-tune the gain until the sound coming out of the speakers is free of any distortion and noise.

Troubleshooting

Even the best plans sometimes hit a snag, so if your speakers and amp are not working correctly at first, it’s likely one of these common issues:

  • If you hear noise or the sound is distorted: Recheck the wiring. 
  • If one or more of your speakers aren’t working: Inspect the wiring closely to make sure you wired everything correctly and that all connections are tight. Most often, when one speaker doesn’t work, the connection to that speaker is not solid.
  • If your amp isn’t powering on in the first place: The likely culprit is either the ground, remote, or battery wire. Check all of them individually and rewire if needed until the amp powers on.
  • If you’re getting music, but it sounds like it’s cutting out: It can be a signal that the amp you’re using is not powerful enough to drive the speakers and subwoofer. If that is the case, check the total RMS power of all speakers. The total RMS power of your amplifier should be around 1.5x the power of your speakers.

Remember that the subwoofer is the most power-hungry part of your audio system, so it is likely the problem. If you are confident that the subwoofer and amp are compatible, use a lower-gauge speaker wire to connect them.

Final Thoughts

Connecting the RCA cables to car speakers has to be done through an amp. Otherwise, you won’t get any sound out of your stereo.

The most challenging part of this process is all the wiring that you have to do. 

Thankfully, car amp kits are readily available, and they come with everything you need. You can follow this guide closely, and you’ll be good to go!

Sources

wikiHow: How to Splice wire

MESA/Boogie: What is the best way to connect speakers or cabinets?

Martin

Welcome to ImproveCarAudio! I am Martin, and I love to write about everything related to car sound systems. I strive to provide the most accurate and helpful information about car audio through extensive research, as well as my experience with car audio installations.

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