Upgrading your car's factory stereo system can transform the listening experience in your vehicle. While simply replacing the head unit or speakers can provide an improvement, rewiring the system from scratch allows for complete customization and the ability to add more powerful amplifiers and subwoofers. Rewiring the system properly is crucial for achieving crisp highs and thumping lows. In this guide, I will walk through the full process of rewiring a car stereo system, from choosing the right gear to connecting everything for optimal sound.

Step 1: Choose New Stereo Head Unit

The first step is selecting an aftermarket stereo head unit to replace your factory one. Look for a head unit with at least 50 watts RMS power per channel, pre-amp outputs to connect amplifiers, and the latest connectivity options like Bluetooth, Android Auto, and Apple CarPlay. Brands like Pioneer, Kenwood, Alpine, and Sony make excellent head units with high-quality internal amplifiers for powering speakers.

For my Honda Civic, I chose the Pioneer DMH-1700NEX head unit for its 7-inch touchscreen, built-in Google Assistant, and 5 volt pre-amp outputs. This will provide a solid foundation to build out the rest of my system.

Step 2: Choose Speakers, Amplifier(s), and Subwoofer(s)

Now it's time to select new speakers, amplifiers, and subwoofers to really give your system some power.


Look for component speakers with separate woofers and tweeters. This allows you to place the tweeters higher in the doors for better highs. Popular brands are JBL, Infinity, Rockford Fosgate, and Alpine. Match the speakers to the available channels on your head unit.

For my build, I'm installing JBL GTO609C components in the front and JBL GT7-6 coaxials in the rear.


Adding at least one amplifier will help provide clean power to your speakers. A 4-channel amp can power both front and rear speakers, while a 2-channel amp is ideal for just the front. Look for amplifiers that output 45-100 watts RMS per channel. Brands like Alpine, Rockford Fosgate, and JL Audio make reliable amplifiers.

I'll be running a JL Audio JX400/4 to power my front and rear speakers.


No system is complete without hard hitting bass. Look for subwoofers in 10, 12, or 15-inch sizes from brands like JL Audio, Rockford Fosgate, and Kicker. Make sure to get a powered subwoofer enclosure or an amp with enough power to drive your sub(s).

For my Honda Civic, I'm going with a single Kicker CompC 12" in a ported enclosure powered by a Rockford P300-1 amp. This will provide plenty of tight bass.

Step 3: Sound Deadening

Before wiring up your new gear, apply sound deadening mat to dampen external noise and vibrations for better sound. Brands like Dynamat and Kilmat make excellent deadening mats that stick to door panels and other surfaces. Cover as many areas as possible, focusing on doors and the rear hatch.

For my Civic, I used Dynamat Xtreme to treat the doors, rear hatch, and roof which made a huge difference in reducing road noise and vibrations.

Step 4: Rewire the Head Unit

Now it's time to wire up your new head unit.

Step 5: Install Amplifier(s) and Subwoofer(s)

Time to mount your amplifiers and subwoofer enclosure.

I mounted my JL and Rockford amps under the front seats and my ported Kicker sub enclosure fires rearward in the trunk. 8 gauge wiring connects everything.

Step 6: Install New Speakers

The last wiring step is to install your new front and rear speakers.

My JBL component speakers required custom mounting of tweeters in the A-pillars at ear height for excellent imaging. The woofers fit perfectly in the factory door speaker locations.

Step 7: Tune the System

With everything wired up, it's time to tune your system for the best possible sound.

Proper tuning resulted in crystal clear highs from my front components and hard-hitting lows from the sub. The system achieves an immersive soundstage throughout the interior.


Completely rewiring your car stereo enables you to build a system tailored exactly to your needs for the best possible listening experience. While it requires time and effort, the end result is well worth it. With high-quality gear, proper installation, and tuning, you can achieve remarkable crisp highs and thumping lows. Just follow these steps and take care with the wiring, and your custom stereo will sing. Let me know if you have any other questions!