how to adjust gain on amp

How to Adjust Gain on Amp?

You’ve got an amplifier but there is something holding back the music from blasting at its maximum range. If you would like to improve the bass, increase the frequency, and enhance the notes, you need to adjust the gain on the amp.

Now, how do you do that? In this guide, we break down the steps on how to adjust gain on amp and provide you with different ways to do it for various amps in case one fails.

Ways to Adjust Gain on Amp

amplifier Adjusting

There are many different ways to adjust the gain on an amp and each works differently. The good part is that you can choose one over another for any amplifier so there are no chances of failing to adjust the gain on the amp.

Some of the methods you can use to set the amp’s gain are:

  • By ear – listen to the sound, if it’s a clean audio or a distorted one.
  • By multimeter – use a digital device to hear any clips in the audio
  • By test tones – check for static in the audio by playing a single note and reading the relevant graph plot

How to Adjust Gain on Amp By Ear?

Setting gain on an amp by ear is regarded as the easiest method, and this is how you can effectively adjust the gain on an amp by ear.

  • Adjust the receiver’s volume

Power on your car amplifier or home stereo amp and put on some music, preferably one with different high and low notes.

Set the gain low and maximize the speaker’s volume until the audio starts clipping. Adjust the volume until there is no distortion.

Write down the maximum volume after which the audio starts clipping.

  • Adjust the gain to the receiver

After setting the receiver, turn the gain up (do not change the volume of the receiver) and stop when the audio starts distorting.

Lower the gain and listen for a clean audio. This is the perfect setting for the amp’s gain. Now the receiver’s volume can be adjusted however you wish.

Now that you have the gain set, it’s time to use it to the amplifier’s benefit and amplify the audio bass. To do that:

  1. Set the amp’s gain to zero or its lowest position
  2. Set the low-pass filter at its highest
  3. Power off the bass boost so it can be adjusted later
  4. Make sure to turn off the subwoofer’s low-pass filter and bass boost too
  5. Play some music and listen for distorted audio by turning the gain up and then adjust it until you hear a clean audio
  6. Control the tone of high and mid-frequency notes by setting the low-pass filter downward
  7. Turn up the bass boost and if the audio is distorted, lower the gain until the audio is clean

Lowering the gain is a simple way of troubleshooting audio distortion but if that doesn’t seem to work, you might be in need of a higher-power amplifier and subwoofer.

How to Adjust Gain on Amp Using a Multimeter?

Multimeter on gray background

Adjusting the gain on an amp by ear may be easy but it has its challenges considering we’re all built differently, and some may hear higher distortions while others won’t.

An accurate way of adjusting the gain on an amp is using a digital multimeter, a device that measures voltage, electric current, and resistance at greater ranges of value.

How to adjust gain on amp using the multimeter:

  1. Unplug the positive terminal amp connection with the positive speaker wire.
  2. Power off the volume, bass boost, treble, and all other EQ functions or set them at the lowest extreme settings.
  3. Lower the gain down to zero by turning it counterclockwise, and make sure the voltage selector is at its lowest or zero.
  4. Maximize the speaker’s volume by adjusting the radio dial to the highest volume and then multiplying that number by 0.75. You’ll get the ¾th value of the speaker’s maximum volume.
  5. Set the head unit volume to the value calculated.
  6. Adjust the gain by calculating the voltage where v = square root (watts x ohms). First, multiply the given power output and impedance of the amplifier, then calculate the answer’s square root.
  7. Insert a test CD with a sine-wave test tone at 0 dB level. If you have a subwoofer amp, adjust the frequency range between 50 Hz to 60 Hz and for a midrange amplifier, set it up to 1000Hz.
  8. Connect the digital multimeter to the amp at the speaker outputs such that the positive end of the DMM joins the positive terminal of the speaker wire and vice versa.
  9. It should ideally display a low voltage in which case slowly adjust the amp gain up to the calculated voltage.
  10. If a high voltage is displayed by a DMM, recheck if all EQ functions have been turned off or set to zero along with the gain adjustment.
  11. With the voltage adjusted, disconnect the DMM and reconnect the speaker wires. Turn on the EQ functions and de-slot the test tone CD.
  12. Play a track (preferably one with various high and low music notes) and listen for any audio distortions.
  13. Ideally, there won’t be any. If there are, repeat the steps, try a different method and if all else fails, look for a higher-power subwoofer and amp combination.

How to Adjust Gain on Amp Through a Specific-Frequency Note

Also known as a test tone, a single note found on a level-setting disc that is played at a specific frequency can help you adjust the gain on an amp.

It doesn’t require as much concentration as the ear method or technicality as the digital multimeter method because it is simply based on observation.

How to adjust gain on amp using test tones:

  1. Set the EQ functions of the receiver and amplifier to your average setting.
  2. Disconnect the speaker wires and set the amp gain to its minimum.
  3. Play a single note and turn up the receiver’s volume until a noticeable bend or distortion is seen in the sine-wave.
  4. Keep adjusting and write down the volume where the audio is clean, as well as the maximum volume of the receiver just before the audio starts clipping.
  5. Play a test tone and repeat the steps to adjust the gain on the amp.
  6. Match the gain with the power output of the amplifier and the max volume of the receiver
  7. For further accuracy, calculate the optimal voltage of the gain by multiplying the power output (watts) of the amplifier by the speaker impedance (ohms), and then taking out the answer’s square root.
  8. Connect a digital multimeter and check if the displayed gain-matched voltage matches the calculated voltage.

Frequently Asked Questions

How do I know if my amp gain is too high?

You’ll have to match the head unit’s volume control with the system’s gain. When the system’s gain is maxed out, the sound may start to distort, cut in and out, or project a static noise. This will tell you that your gains are too high.

What happens if the gain is too high?

When the gains are maxed out, the sound you hear may be distorted or the audio may be clipped at the output. It isn’t really a deal breaker, in fact, some musicians deliberately set the gains high if their music needs the extra static. For a clean-toned audio, you may have to adjust the gains better.

What happens if the gain is set too low?

When the gains are adjusted to a lower setting, the amplifier’s power may be limited. This will result in a lower bass clipped sound and distorted audio. Also, output at the speakers may not reach as clean tones and most notes may get missed.

What should the gain be set at?

It depends on what way you choose to identify the correct setting for your gain. But as a general rule of thumb, when nothing works, adjust your stereo’s volume to 2⁄3 the max volume and then adjust your gain until there’s no distortion in the sound. You’ll know the gains maxed out when the audio is clipped.

What happens if the gain of the amplifier is not properly maintained?

An amplifier is connected to a speaker to enhance the bass of a sound meaning it balances the input signals. The gain of the amplifier facilitates the input signal by creating harmony between the different notes and then delivering a clean-toned audio to the speaker. When it isn’t properly maintained, the output may get distorted.

Final Thoughts

Adjusting the gain on an amp is easy and does not require many technicalities. All you need is the basic know-how. Now that you’ve gone through this post, you know how to adjust gain on amp and why it’s necessary.