How to Tune and Adjust a Car Amplifier

So, you just bought and installed a wicked new amplifier in your car’s stereo system, but when you fired it up, it doesn’t seem to do anything. Don’t rage just yet, and there’s nothing wrong with your brand-new amplifier, it’s just not properly tuned yet.

You need to tune and adjust a car amplifier to make the most use of the car’s speakers; you need to do a bit of tweaking until you get the right audio quality for your listening pleasure.

Don’t worry, tuning a car amplifier or a subwoofer isn’t as hard as it sounds.

The Terminology of a Car Amplifier

You will be encountering quite some technical terms in this article, so you should familiarize yourself with them so you won’t get lost.

Gain – This is the setting that adjusts the sensitivity the amplifier, meaning it sets the power coming out of the amplifier to a certain level that can be easily handled by the speakers. Simply speaking, you adjust this setting to reduce the amount of distortion coming from the speakers.

Frequency – This is the pitch of the sound that the speakers emit. Finding out the frequency of your speakers is quite easy as they are usually clearly labeled on the speakers outer casing. If not, you can find the frequency numbers at the back of each individual speaker. You will need to get these numbers because you will need them to tune an amplifier correctly.

Low-pass/High-pass Filters – These are built-in frequency filters that, when turned on, will only let a maximum/minimum range of frequencies pass through the output jacks. For instance, if you will be using small speakers, like tweeters, to handle the high-frequencies, you will need to turn on the HPF on the corresponding output channels. Also, if you will be using all medium-sized speakers (no tweeter and subwoofers), you can set the filters to “full”, meaning the output channels will let out a full range of frequencies (lows, mids, and highs).

How to Tune an Amplifier.

Step 1 – Volume and Gain Control Adjustments

Turn everything off, unplug the RCA cables connected to your amplifier, and turn your stereo system back on. With no music playing, turn up the volume on your head unit all the way up, and take note of the number displayed on the head unit.

Now that you know the maximum volume of your system dial it back down to around 80%, and then set the stereo’s Equalizer settings to “Flat”. Go back to your amplifier and set the Gain and Bass Boost to zero, and set the crossover filters to off/full. Plug back all of the RCA cables into the speaker channels that you want to tune (most aftermarket amplifiers have separate RCA jacks for low, mids, and highs). Now, play your favorite music on the radio, and then slowly increase the gain setting until you hear a bit of distortion coming from the speakers. Slowly reduce the gain until you don’t hear any more distortion, this will be the base gain setting that you will use to tune the different frequencies.

Step 2 – Tuning Individual Frequencies

Now that you have your base gain settings, it’s time to switch the crossovers and filters back on. If you’re tuning your sub-woofers, choose the low-pass filter (LPF), and use the high-pass filter (HPF) for the other speakers. If you are using mid-sized speakers to cover all frequencies (meaning you don’t have a sub-woofer box installed), you can disregard this step and just leave the crossover and filters on the off or full position.

If you are tuning your sub-woofers, check the maximum rating of your sub-woofer and then set the frequency dial to the same number. On the other hand, if you’re tuning the rest of the speaker system, find out their lowest frequency rating and set the frequency setting to that number.

Step 3 – Bringing the Bass

If you’re the type of person who likes chest-thumping, window-rattling bass coming from your car’s sound system, then you need to increase the bass boost setting of your amplifier. Do take note that this can be quite tricky, and will also place a lot of stress on your sub-woofer.

To turn up the bass boost, you need to set the gain down. You need to adjust these two settings at the same time, your goal here is to get the highest bass output without getting any distortion. This might take a while since you will be adjusting two settings at the same time, but don’t worry, it will all be worth it in the end.

Step 4 – Back to Gains

Now that all of the speaker frequencies and bass boost are set up, you can go back to set the gain. Turn on your radio and set the volume back to 80% of the maximum, turn the gain up slowly until you hear any distortion coming from any of the speakers, and then gradually dial down the settings until the distortion disappears.

Step 5 – Fine Tuning

Reconnect all the amplifiers (that is, if you were tuning them separately) and then turn the stereo’s volume all the way down to zero. Now, gradually turn up the volume until you reach the 80% mark or until you hear any distortion. If you have turned everything correctly, you will hit the 80% volume without hearing any distortion whatsoever.

On the other hand, you hear any distortion, find out which speakers are the culprits and then turn down their gain settings until they no longer distort.

Final Notes

You should never exceed the 80% volume setting on your stereo, prolonged use at maximum setting will increase the wear and tear experienced by the speakers, and of course, you also risk tearing up your eardrums.

Also, different genres of music will need different amplifier tuning settings. For instance, you want a lot of basses if you like listening to hip-hop and rap, but not so much if you like country or folk music. If you like listening to two or more different music genres, then you need to tune and adjust a car amplifier to find the happy medium between all of them.


high-pass filter (HPF) - wikipedia
low-pass filter (LPF) - learningaboutelectronics

25 thoughts on “How to Tune and Adjust a Car Amplifier”

  1. Thanks for the great tips on how to set amplifier gain and preventing distortion. Your step by step guide and terminology really break down how to adjust sound and have the full speaker experience.

  2. While this is perhaps the most basic topic ever in my opinion. However, I guess this is for people who might not be familiar with tech? On particular, how to set amplifier gain. Again this is not for me but at least if anyone not tech savy can read this they will know what to do.

  3. I am glad to have finally learnt how to set amplifier gain and basically set the whole thing up. I can’t wait to try it out myself.

  4. In my quest to find the best settings for rockford fosgate amp I have found your write up to provide the best instructions. I appreciate the work that went into this.

  5. Anyone looking to know more about how to set amplifier gain ought to find this article incredibly useful. I will share this with a few of my friends.

  6. Can I use these settings for subwoofer frequency setting car? The steps are very detailed and well explained.

  7. How to set amplifier gain is seemingly quite easy. With a little practice anyone should be able to do it.

  8. Rockford fosgate r500x1d tuning relies on this principle too. Thanks a lot for the article. It will provide a good reference source for me in future.

  9. Dont panic because your new audio machine doesn’t seems it, adjust amplifier gain, you need to tweak it to enjoy its superb output. Learn how to adjust your high and low filter

  10. The subwoofer frequency setting car us not to difficult, just try understand the high and low frequency. As loud as this machine is, never exceed 80% for you own good😃👌

  11. I do not know if this is indeed the best amp settings for bass in car but I may try this steps to see if it checks out. I am gonna pimp my car with a new system soon as a gift to myself? Thank you for sharing.

  12. Here are various techniques on how to tune a monoblock amp. Little tweaking is needed to bring out the best from your amplifier. Enjoy your machine

  13. how to tune a subwoofer can be funny If you know what I mean. I never knew their is gain, frequency etc to be considered when tuning your sub woofer. This post is helpful

  14. Learning how to tune a subwoofer will make you have a pleasant experience when listening to music..thanks for this important article.. Now,I know how to get a high quality sound when I tune my subwoofer correctly.. Spot on

  15. These are all really great tips in how to adjust car amp for best sound ever. Drivers should make the most out of their car audio system so that it will be a smooth and easy ride from start to finish.

  16. This post is very helpful, it talks about each feature and descrives step by step how to adjust car amplifier settings.

  17. Thanks for listing how to adjust car amp for best sound. These are great fundamentals to capitalize on premium sound without distortion and finding the right balance with each genre of music. I like that there’s a way to tune individual frequencies and increase the bass boost setting. Great read.

  18. Only few people think about how to adjust car amp for best sound. Now this article has it all to make you feel big. Thanks for this good post.

  19. All car owners should take note of this great article. I also believe in taking serious cognisance of the manual that comes with the car where the amplifier section is and by checking how to adjust car amplifier settings, then the car owner can be rest assured of not tampering with a part that could damage the system.

  20. I have always wondered how to adjust car amp for best sound. Every time I tried seems like it always comes out muffled. Now I will follow the advice in your article to tune individual frequencies and hopefully that will help, thanks!


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