How to Test Amplifier Without Speakers: 4 Easy Steps

You must test a car amplifier to ensure it can run smoothly and enhance your car’s audio system. But what if you don’t have speakers when carrying out this project? How to test an amplifier without speakers

If your stereo system doesn’t have a speaker now, you need to focus on other factors that illustrate the amp’s efficiency. The detailed guide in this post will help you find the way to solve the question “How to test an amplifier without speakers?”. Let’s check it out! 

How To Test An Amplifier Without Speakers? 

Using Multimeter

Testing an amplifier without speakers is similar to testing an automobile engine separately from the car. The goal is to test amp circuits without any speaker linked to them. 

While testing the amp, you need to focus on the audio signal and output performance. If the two sections perform well, your amp will play sound without any problem. 

Often, you may want to perform this test in these cases:

  • You intend to use the amp to drive subwoofers or include it in a surround sound system. 
  • You want the amp to handle multiple speaker types.
  • There isn’t enough time to install and test every speaker. 

You cannot tell if the battery-powered amplifier is functioning or not because it doesn’t produce sound. 

Moreover, it works in relation to many other components, such as the power wire on the positive battery post and the ground wire on the negative battery post. Hence, it would help if you used multiple tools to test its input, output, voltage drop, and frequency across the system.  

We will split the whole testing process into four steps so you can follow it easier. And please note that the method aims to test the amp without speakers. So disconnect the speaker wires first, if you have them. 

Step 1: Set the multimeter 

Although a car amplifier runs on DC voltage, it may convert low voltage/current to a higher output signal reading. So, you can test the amplifier output by setting the multimeter to the AC voltage. It’s “VAC” on the meter. 

You should also set it between the 10 and 100 VAC range to guarantee that the multimeter gives accurate results.

How to test an amplifier without speakers? You need to use a multimeter

Step 2: Connect multimeter probes to amplifier output terminals

Now, work with the positive and negative probes. The positive one should go to the positive amp output terminal, while the negative one aims for the negative terminal. 

If you bridge the terminals or run your car amplifier in mono mode.

Step 3: Set the frequency 

Running an exam tune is the simplest way to set a frequency to do testing on the amplifier signal outputs. You can play a song from any input source or use a CD.

The frequency at which this song is playing must be appropriate for the speakers you have, though, because it’s what matters most.

But in which frequency range should it be played? If you have subwoofers, set 50HZ for 0dB. Meanwhile, 1kHz for 0dB is ideal for tweeter and midrange car amplifiers. 

You could also employ a signal generator for the test. Here is what you should do:

  • Remove the output and input wires from the amp. 
  • Use RCA cables to link the input terminals and signal generator. 
  • Set multiple probes on the amp’s output terminals. 
  • Set the frequency to the right level for the speakers with the signal generator activated. 
Set up the frequency

Step 4: Check the result

After setting the test frequency and writing down the result, you need to do some math.

You can find the suggested watt output for amplifiers on the amp chassis or in the user handbook. It often ranges from 50 to 200 watts.

To calculate the watts of your amplifier, use this formula:

Watt = E²/R

E: Voltage

R: Resistance 

After getting the result, compare it with the recommended watts. Your amplifier needs improvements if the calculated result isn’t close to the suggested figure. You should check it to upgrade or change it if necessary. 

For example, if you use a subwoofer with a resistance of 8 Ohm and the voltage reading is 26, the watts will be:

Watts = 26 x 268 = 169 

If your car amp’s recommended wattage is only 100, then it may not be a perfect match for your stereo. 

Using Headphone

You can test speakers with headphones without using speakers. Here is a step-by-step guide:

Step 1: Set up your amplifier

In the first step, place the tripod underneath your amplifier and position it at the height of your line of sight, and covers sound-emitting surfaces.

Step 2: Remove the speaker

In this step, first, remove the speaker from the cabinet. Then, at the output of the amplifier, plug in an additional audio cable. When removed, you will see a small error on the left side of the cabinet, you will plug the cable into this place.

Step 3: Use a headphone test amplifier

Now, prepare the headphones for testing. So, you plug the other end of the cable into the headphones and put them on. Avoid touching the cable while listening, as this could interrupt or damage the audio signal.

Step 4: Test your amplifier

When you are finished listening to the music, measure and record the amplitude of the sound. To get accurate results, choose a headphone tester that fits your budget and needs.

Check the sound quality


After reading, we hope you will use this four-step project to solve the big question “How to test an amplifier without speakers?” You don’t need to examine the audio equipment in your car as a whole. Without the speakers, you can still tell if your car amplifier is working well by taking some steps. 

This test involves handling the AC voltage, input signal, and some cables. By following our guide, you can nail it.

Thank you for reading! If you have any questions, please comment in the section below. We will get back soon to help you out.

This video will give you a clearer idea of how to measure the amplifier output using a multimeter:

  1. Does an amplifier require speakers to work?

    Tube amps that use power tubes in the part that sends out sound need to have a speaker connected to work safely. The transformer in this part of the amp changes the speaker load into a load that the tubes can deal with. If there's no speaker connected, the transformer might send too much electricity back to the power tubes, which can break them.

  2. How can you tell if an amplifier is blown?

    Two simple ways to figure out if your amplifier is broken include looking at the fuse and listening to the sounds it makes. If the fuse is broken, it's likely the amplifier is too. Also, if the amplifier makes odd noises, like pops or crackles, it could be broken.

  3. How do I check the output of my audio amp?

    If you want to check an amplifier with a multimeter, first unplug all wires going in and out of the amp. Then, connect your signal generator to the amp's input using RCA cables. Next, put your multimeter's probes on the amp's output. Lastly, turn on the signal generator and change the frequency to match your speakers' needs.