4 Ways to Modify a Car Stereo

Get louder and higher-quality sound with these in-car entertainment tips.

Two women in a car laughing and listening to musicShutterstock

Article QuickTakes:

Old cars with good stereos aren't always easy to find. Whether you're looking to upgrade from a cassette deck in a classic car, improve the sound in a more recent vehicle, or add features that didn't come from the factory, there are several options available when it comes to modifying and upgrading your vehicle's basic stereo system.

Swap in New Speakers

Replacing stock speakers with aftermarket units can make a big difference in the sound quality and power of the music in your vehicle. Think about focusing on the speakers closest to the driver first, since those are the ones you hear most when behind the wheel. The first step toward improving your vehicle's audio abilities is to find out what size of speaker will fit in your door or your dashboard. There are online configuration tools that often have the specifications for your vehicle.

From there, it's a matter of deciding between full-range speakers, component speakers, or individual component speakers. This will largely depend on the space behind your vehicle's body panels and how the car's existing audio setup is integrated.

Add an Amplifier

It's possible that your factory stereo system won't have enough power to get the most out of your new speakers. Enter the amplifier: a piece of audio equipment designed to send more signal to a speaker without overloading or overdriving it. (These devices amplify the signal so your speakers can play the sound.) This allows for clear musical tone even at higher volumes.

If you're sticking with your stock head unit, an amplifier that can accept speaker-level inputs might be your best bet, since those inputs let you connect the speaker output signal with the amplifier. Some factory designs might also offer a line-level output, which can mean a cleaner sound. You should also match your amplifier's power output to the RMS rating of each of your new speakers. RMS, or root mean square, has to do with an amplifier's ability to handle continuous power without affecting sound quality.

Boost Your Bass

If you want to get deep into the bass of the music you listen to, consider installing a subwoofer. This specialized speaker is intended to reproduce only the low-end frequencies in a track, giving them deeper resonance and volume than the rest of the mix.

Your vehicle might have a subwoofer already installed, in which case you could upgrade rather than doing a new installation. If there's no subwoofer present, the one you install should be paired with an amplifier, and potentially also a crossover (a filter that can block specific frequencies in certain speakers to optimize sound quality), in order to get the most out of it. Keep in mind that subwoofers can be physically larger components that could eat up some trunk or under-seat space, depending on where you install them.

Install a New Head Unit

All of the above can usually be used with a stock stereo system without any problems. But if you want to add features to your vehicle's entertainment system, such as satellite radio, a CD slot, or a USB port, you might be better off replacing the factory design with a new head unit from the aftermarket. Head units for cars are most easily thought of as the control center of the entire audio system.

There are a few things to keep in mind when choosing an aftermarket head unit. The first is the size. Standard, rectangular slots called single DIN are common on older cars, while larger, screen-friendly sizes are referred to as double DIN. Not all dashboards are compatible with all head-unit designs, so matching up with the right size and shape is crucial.

It might also be worthwhile to consult an expert in car-stereo installation — before getting started or at any point in the upgrade process.

This site is for educational purposes only. The third parties listed are not affiliated with Capital One and are solely responsible for their opinions, products and services. Capital One does not provide, endorse or guarantee any third-party product, service, information or recommendation listed above. The information presented in this article is believed to be accurate at the time of publication, but is subject to change. The images shown are for illustration purposes only and may not be an exact representation of the product. The material provided on this site is not intended to provide legal, investment, or financial advice or to indicate the availability or suitability of any Capital One product or service to your unique circumstances. For specific advice about your unique circumstances, you may wish to consult a qualified professional.
author photo
Benjamin Hunting
Benjamin Hunting is a writer and podcast host who contributes to a number of newspapers, automotive magazines, and online publications. More than a decade into his career, he enjoys keeping the shiny side up during track days and always has one too many classic vehicle projects partially disassembled in his garage at any given time. Remember, if it's not leaking, it's probably empty.