How to Measure Speaker Wattage with a Multimeter

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New to electronics? Don’t know how to measure speaker wattage with a multimeter? Start here. While playing music is the most common use for speakers, many people use them for home theater and stereo systems as well. If you have more than one speaker in your system, you will quickly realize that wattage is a key specification when shopping for new speakers: the higher the wattage, the louder the speakers. If you have multiple speakers, you may also see the term “RMS” or “Watts per channel,” which are both abbreviated “WPC.”

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Measuring It With Multimeter

Most people think that you can’t measure or control the “wattage” of a speaker. This is not true. You can control speaker wattage within limits. For novices, learning how to measure speaker wattage with a multimeter can be a challenge. 

Here is a simple tutorial that breaks down the process and gives you a better understanding of what you can do with your multimeter:

  • You will need to get a multimeter. This is a device that measures a current flowing through a circuit and has a number of other useful features. For this application, you will need to measure AC and DC current and voltage and have a resistance measurement feature. To measure the speaker wattage with a multimeter, you need to use the Ohms setting. A speaker is basically an electromagnetic coil that reacts to an electrical signal. The speaker’s power rating should be included in the speaker’s specifications and is typically given in watts.
  • You will need to turn the speaker on and place it in a location where you can safely measure the wattage. You can connect the speaker to an AC outlet or a 12-volt power source. Set the multimeter on the 20 volt AC scale. Depending on the type of speaker, you should either place the black probe on the negative terminal of the speaker or on the wire that connects the speaker.

It is worth noting that the voltages applied to the speaker and the frequency that the speaker can produce are factors that we control. So, in the end, our speaker will be a device that produces voltages that vary sinusoidally with time.

Knowing More About Speaker Wattage

Speaker wattage is measured in watts and is the amount of power that is required to drive a speaker to produce sound at a particular volume. The amount of power a speaker needs to produce sound is dependent on the impedance or the “load” the speaker sees. If you adjust the volume on your stereo to 3 o’clock and listen to a song, you will notice a change in the sound. You will also be able to look at the amplifier’s wattage on the front of the device and know roughly how loud that song will be.

Most speakers operate on a range of voltages that are supplied by the amplifier (the thing that makes the speakers work). You can tell how much power you’re supplying to a pair of speakers if they are rated for 8 ohms or higher. You can tell this by checking the speaker-specific details of the amplifier you’re using or by checking the speaker’s frame. The mark is usually a big “8” or “4”, or something similar. The number of ohms indicates that the speaker designer has already accounted for half the power of the speaker. To determine the proper wattage, you simply multiply the number of watts by the number of ohms.

Speaker wattage is a measurement of the amount of power a speaker is capable of producing. Speakers that can produce more wattage are better able to fill a larger room with sound than those that are less powerful. This makes speaker wattage an important thing to consider when shopping for a new speaker system. However, speaker wattage is not as straightforward a measurement as it might seem. If you’re wondering how to measure speaker wattage with a multimeter, here are some tips that will help you find the correct wattage rating for your speakers.

Why Should You Measure The Speaker Wattage

Speaker wattage is essential because it shows you how much power the speaker is using to give you the desired sound. This is important because if the speaker uses too much power, the wires in the speaker may melt and cause an electrical shock as well as a house fire in the speaker.

Some people think that wattage is the only important factor to pay attention to when buying speakers. This is not the case – sound quality is generally better when you have a lower wattage since the speakers won’t have to work as hard to produce sound. However, there are exceptions to this “rule.” If you have a really big space, you need to fill, or play at really high volumes, then having a higher wattage speaker can be useful. But remember, a higher wattage doesn’t necessarily mean better sound quality. 

The wattage rating tells you how much power the speakers can handle. If a speaker is rated at 100 watts, for example, you should not connect the speaker to a receiver that is rated at 200 watts. Doing this could damage the speaker.


As a music lover, you may have noticed that your favorite songs seem to have lost some power and volume. If you have been experiencing this, you may have even tried to compensate by turning up the volume control on your speakers and/or stereo system. While this may seem like a quick fix, doing so will decrease sound quality. You will lose a lot of quality by just turning up the volume, and you will also cause your speakers to wear out a lot faster. To maintain sound quality and keep your speakers from wearing out, you should measure the speaker wattage.

The speaker wattage is an important measurement in regards to the sound output of a speaker. The wattage is measured in watts, and it is calculated by multiplying the voltage and the current. The voltage will be found in the specifications of the speaker, so it is important to pay attention to that.

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