Car Amplifiers

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What Does A Car Amplifier Do?

Amplifiers work to enhance sound by increasing the power output to speakers, which improves the sound quality and volume. In a car audio system, having enough power to ensure clear and loud sound is crucial to combating road noise and other competing sounds.

Most Factory Sound Systems are Underpowered

The typical audio system supplied by a car manufacturer is underpowered. While the radio can play most music at moderate listening levels, the sound is typically limited in range, meaning it doesn’t play the full frequency range properly. If you have ever turned up the bass on a factory system to hear the beat, you’ll notice the sound begins to distort rapidly. This is caused by the internal amplifier running out of power and preventing the low notes from being properly reproduced.

How Does a Car Amplifier Work?

Put simply, amplifiers boost or increase existing sound signals to improve speaker output. In turn, this power increases the volume that speakers produce, improving the overall car audio experience and eliminating-or at least reducing-road noise and other interference.

The boost to the audio signal comes from the amplifier’s ability to provide additional power to the system. An amplifier can provide enough power to adequately drive a speaker with extra energy left over for subwoofers, further improving sound quality by adding more audio range that speakers alone would not be able to provide. Car audio amplifiers also allow for more adjustments and personalization within the car’s sound system that a speaker alone may not have been able to offer.

While most car audio systems come with a built-in amplifier, and many drivers find the sound quality fine, others believe a aftermarket amplifier provides a much better sound. The factory stereo system will, generally, produce around 10-25 watts per channel provided. They also take up minimal space in the dashboard, reducing crowding. However, this low power only allows for so much sound reproduction and volume. Many audiophiles prefer a higher power, clearer sound, and higher volume that an aftermarket amplifier can provide.

How Amplifiers Create Power

Car speakers need a lot of power, typically at least 20 volts of peak-to-peak voltage, which allows them to reach 100 watts. Most amplifiers configure this with a power supply that converts the car’s DC (Direct Current) method to AC (Alternating Current) since that is what’s used to drive car speakers. Amplifiers provide the connection and adjustments needed to get the correct type and amount of power required.

To convert the DC current into the necessary AC signal, amplifiers produce turn on electrically controlled switches like MOSFETs. These switches pulse the voltage quickly, off and on again, essentially creating an alternating current needed to correctly produce the correct electrical signal for the speakers.

What to Look for in an Amplifier

When looking for a new amplifier, avoid companies that market their “peak” or “max” power ratings rather than the CONTINUOUS RMS or DYNAMIC RMS ratings. You are not likely to keep your car stereo at its maximum power output for long, if at all. The RMS power ratings give a more reliable rating for actual use, as well as a more dependable measurement for comparing amplifiers on the market. Companies that market their “peak or “max” power ratings don’t actually produce that amount of wattage in real-world conditions. That is, connecting the amplifier to a rear speaker and powering it with music. They typically derive their power ratings on a test bench using test tones and resistors. Some actually take their power ratings and multiply them by 2-or-3 times to claim a “peak” wattage number to put on the box. When shopping for a car audio amplifier, look for ones that follow industry standards, such as those certified by the Consumer Technology Association (CTA), a consumer protection group that seeks to provide standards for consumer electronic devices. Manufacturers that certify their power output based on industry standards are more honest about how many watts their amplifier can produce. Like the old saying goes; if it’s too good to be true, it probably is.

Does a Car Amplifier Improve Sound Quality?

For most people, the first instinct upon hearing sound distortion or poor audio quality is to blame the speakers. However, in most cases, distortion is actually caused by the amplifier. When a car audio system reaches 3/4 or 75% of its full volume, built-in amplifiers often don’t have the power supply and distort the sound. Obviously, this means that you can not have an optimal listening experience at full volume. Built-in car amplifiers typically cannot produce the right amount of power. However, an aftermarket amplifier with a higher RMS rating can be added to the sound system, one that will handle more volume and more power and improve the sound quality, decreasing the likelihood of distortion.


If you opt for an aftermarket amplifier to improve your car’s sound system, Rockford Fosgate can help you find the right equipment to meet your needs. With the right equipment, installation should be taken seriously. As mentioned above, amplifiers for car audio handle a great deal of electrical current. If the proper equipment is not chosen, or if it is not installed correctly (using the right fuse, having properly connected power/ground, and even using good electrical cables) there could be a poor audio signal and possibly dangerous electrical connections.

Adding a new car amplifier to update your system’s sound is easier than before. Many newer amplifiers are equipped with a higher efficiency circuitry by using Class-D class, whereas older models typically use a Class-A/B design. Class D amplifiers produce less heat and take up less space and are very efficient in amplifying power and audio signal.

Rockford Fosgate can help you choose from an excellent selection of amplifiers and find one that matches your vehicle’s current system. With a new amplifier, you’ll be improving the RMS power output and the overall sound quality so that you can truly enjoy your audio experience.

More Information

Find Car Audio Amplifiers for your audio system.
• Rockford Fosgate Prime Series Car Audio Amplifiers
• Rockford Fosgate Punch Series Car Audio Amplifiers
• Rockford Fosgate Power Series Car Audio Amplifiers