How to Measure Sound Output of Speakers

After all the money and effort you spent in setting up your audio system, it is only normal for you to expect high quality and great sounds coming from it. Most of the time, people prefer sounds that fill the room with a rich middle range, clear treble, and deep bass.

How to Measure Sound Output of Speakers

The quality of the sound should weaken when you increase the volume. Of course, you definitely don’t want static hiss, weird vibrations, and worse, even smoke coming out of your precious speakers.

If you are interested to learn how to measure sound output for speakers and you are hoping to create quality sound, one figure you need to understand and consider is speaker watts. Other equally critical values are the sensitivity of the speakers and the THD or total harmonic distortion.

This article hopes to serve as your guide in interpreting the specifications of the manufacturer so you will know what you can expect from your sound system.

Difference between Speaker Power and Loudness

To understand the sound output of your speakers, there are two things that you should be familiar with and what makes them different from each other. These are loudness and power.

Decibels are the measure of loudness. It is an important number when shopping for speakers, particularly for those people who love listening to their favorite songs or watching their favorite TV shows at high volumes.

One important thing to note about decibels is that for every increase of 10 decibels, the noise will be two times as loud. This only means that even the smallest increases in the decibel levels can already mean a significant impact on your ears.

On the other hand, electrical power is measured in watts. As the amplifier processes the sound, its output will be measured in terms of watts. Every speaker has its own maximum number of watts that it can cope with. This is something that the manufacturer will inform you about.

See to it that the amplifier you use doesn’t produce more power than what the speakers can handle. If this happens, your speakers may end up damaged.

Most of the time, manufacturers offer two figures of power for the loudspeakers and amplifiers alike.

For speakers, these are the peak power and nominal power:

Peak Power

This is what a speaker will be able to handle in shorter bursts without incurring any damage.

Nominal Power

This is what a speaker will be able to handle for the long term without incurring any damage.

For the amplifiers, power is measured in terms of peak and RMS.


This is the power that can be put out by an amplifier in short bursts.


This is the power that can be put out by an amplifier over an extended period.

Speakers that are of really good quality tend to be more sensitive compared to their mid-quality counterparts, not to mention that these can also deliver plenty of sound with just a bit of power coming from the amplifier. The mid-priced speakers require more power to offer the same level of volume.

The speaker sensitivity is being expressed through the number of dB or decibels of SPL or sound pressure level for every watt of amplifier power that is measured at 1 meter from the speaker. To put it in simple terms, manufacturers often choose to ditch the SPL/W/M and simply say dB instead.

The majority of speaker sensitivities today belong to the range of 85 to 91 dB, which means that anything lower than 85 dB may not be that hot at all.

How to Judge the Quality of Speaker Sound

Here are other figures you need to look for and consider when shopping for new speakers.


Headroom is the measure of what a speaker system will be able to deliver in short bursts. It is important to have a large headroom figure if you own a home cinema system and you prefer getting a jolt from all those thrilling explosions in your favorite action films.

Speaker Impedance

Speaker impedance is the figure that lets you know the amount of current that will be drawn by a speaker. The standard here is 8 ohms. While 4 ohms can already be considered very good, most of the time, it is, unfortunately, a lot more expensive. You will also need to make sure that you will get a very good amplifier if you plan to buy 4 ohms speakers so you can enjoy them to the fullest.

Total Harmonic Distortion

Total harmonic distortion or TDH is the measure of how authentically a speaker translates into sound whatever is on the hard drive or disc. You can expect less distortion if the figure is lower, which means that it will be better to go for lower numbers. In most cases, values that are ranging from 0.05% up to 0.08% THD only mean a clean and quality system. However, any figure that is lower than 0.1% THD is also pretty good.

The Bottom Line

The main takeaway here is that even if you should never overlook the number of watts of a speaker, this doesn’t necessarily tell you how loud your speakers can go. The wattage of speakers is also not an indication of sound quality or even possible lifespan.

However, this can really come in handy if you are planning to get a new suitable amplifier soon. You also need to remember that it will be better if you choose an amplifier that has too much power.

For you to get a much clearer idea of how loud your speaker can sound, make sure you don’t simply look at the number of watts. You also need to consider other things such as sensitivity specifications and SPL.

See to it that you consider all the different factors that affect sound output the next time you go shopping for new speakers. Use this article as your guide to finding the perfect speakers for your needs that produce the kind of sounds you love.