We’ve all heard that one car cruising the block, just blasting fuzzy garbage audio from some blown-out woofer in the trunk. Fortunately, with proper understanding of your setup, there’s no need to be that guy. You can crank the volume in your car while still enjoying a crisp, clean quality of sound, so long as you properly tune your amplifier.

This was a challenge for me when I installed my first sound system. I’m not an electrician, nor a stage manager for a rock band, and when I tuned my first amplifier, it just seemed like a lot dials I didn’t know how to use and jargon I had never heard. That’s why I put together this article, to simplify the concepts, and hopefully spare someone a little frustration and confusion.

How does car amplifier work?

First, we need a basic understanding of the parts and processes involved. Your car already has what is called a “head unit” this is simply the CD player or radio installed in your vehicle. Your head unit sends out an electrical current to your normal car speakers, somewhere in the ballpark of 0.5 to 2 volts. This current contains all the information your speakers need to turn it into music.

However, the current also powers the speakers, and while two volts may be enough to power your standard-issue door speakers, you wouldn’t be tuning an amp if you didn’t have something bigger in mind. The larger the speakers, the more juice they’re going to need, and this is the main purpose of your amp, it simply “amplifies” the electrical current to a higher voltage without changing the musical information.

Your amp must be “in tune” with your speakers. Every piece of electrical equipment has an optimal voltage. Too much current, and you can cause distortion, clipping, and stress to the speakers which will damage them over time. Too little, you won’t be able to hear it.

How do I tune an car amplifier?

To tune your amp, you’re going to be adjusting the “gain.” Gain simply represents the change in voltage. Gain is not a volume control, though changing it can also change the volume.

If you’re handy at math, know the specs of your equipment inside and out, and have a voltmeter lying around, you can simply calculate the exact voltage for your equipment and adjust your amp accordingly. However, for those of us who are a little less advanced, there’s a much easier method I’d like to discuss.

Step 1. Turn the gain all the way down and turn off any filters or special settings. We’re starting at ground zero.

Step 2. Turn up the Car stereo until you start to hear distortions, then back it down. It’s like tuning a guitar string. You overshoot then back off to find the sweet spot.

Step 3. Do the same thing with the gain. Crank it up until you just begin to hear distortions, then back it off. Do each of these steps carefully. You can put stress on your speakers if the gain is too high.

Step 4. Turn any filters you want back on and repeat the steps two and three until you get that high-quality audio you’re looking for. Like tuning an instrument, you’re going to find the sweet spot by ear.

Where can I find more information?

The Youtube channel HowcastTechGadgets also has a helpful video that can walk you through this.

Video 1

If you’re confused about all the filters and other options on your amp, I recommend checking out this helpful resource from MTX Audio. Basically, the filters tell your amp which speakers to send the current to. A low pass filter sends current to your subwoofer, whereas high pass filters send it to your speakers or tweeters, and there are plenty of tutorials online for how to adjust these.

Video 2

Tuning your amplifier correctly is essential for maintaining high sound quality and keeping your speakers in good working condition. Fortunately, it’s not that intimidating as long as you understand your equipment and can follow the steps outlined above. Hopefully, you’ll have better luck than I did my first time and start enjoying some high-quality audio at volume.

Video 3

Vincent Talbot