How to Know How Loud a Speaker Is (By Looking at Specs)


speaker specs on laptop screen

With many other forms of computers and electronics, you can do online research, compare the numbers, and get a pretty good idea of what’s best for you. 

Speakers, however, are an exception to that rule. You really have to listen to them to properly judge which sounds best for you. 

Although loudness is the subjective perception of sound pressure in acoustics, speaker loudness is something we can determine by looking at specs.

The sound pressure levels (efficiency/sensitivity), power, and impedance determine the speaker loudness it can produce.

For example, a 95dB (sensitivity) speaker is louder than a 90dB speaker at 100 watts (power), but if the 90dB speaker can handle 105W, it will eventually be louder than a 95dB speaker at 100W.

All speakers sound different; some are louder, deeper, and better than others. But how do you know how they can play by looking at data? 

In this article, I’ll explain it as simply as possible and answer some other burning questions regarding speakers and loudness.

Check How Loud a Speaker is Just by Looking at Specs

As different spaces require different amounts of volume, some speakers advertised as loud might not be enough for your needs.

Conversely, you might require less volume than you can get with some loud speakers out there.

1. I suggest first seeing how many watts you need per square foot, and then when you know the wattage, you can move forward to loudness.

2. Then, you’ll find a few (or more) speakers of the approximate wattage your space requires.

3. Then, you’ll check the other specs: decibels and ohms. 

You’ll often see ratings like this: “120 Watts 86db @ 6 Ohms”. That would mean that 120 watts amplifier power input to the speaker wired or loaded at 6 Ohms would yield 86 decibels (loudness lab measured 1 meter from speaker to listener).

amazon speaker specifications screenshot
ELAC Debut Specs on Amazon (screenshot)

After you check the specs, this is all you need to know when comparing speaker loudness:

  • If impedance (in ohms) and power (in watts) are the same, the speaker that has higher sensitivity (dB) will be louder.
  • If power and sensitivity are the same, the speaker with lower impedance will be louder.
  • If sensitivity and impedance are the same, the speaker with more power will be louder.

What Determines Speaker Loudness?

Three things determine how loud a speaker can play;

1. Sensitivity [db @ 1watt/1m ordB @ 2.83V/1m] – here, you only look at decibels, as it’s always measured at 1m.

This describes how loud a speaker becomes when given a certain amount of power and measured at a specific distance.

For example, as you can see on the Klipsch product description, for sensitivity, it’s a standard to write: 

[number of decibels] @ 2.83V/1m – which means 1 watt for 8ohm, and measured at 1 meter.

So, if you have two speakers (8Ω and 4Ω) with the same sensitivity expressed in 2.83V/1m (for example, 86dB @ 2.83V/1m), it translates to 86dB @ 1W/1m for an 8Ω speaker and 86dB @ 2W/1m for a 4Ω speaker.

2. Power – the power available to drive the speaker [Watts]

Generally, the more power, the louder the speaker gets.

3. Impendence [Ohms]

This tells you how hard it is to drive the speaker. Speakers with low impedance ratings offer lower resistance to the dynamic electricity supplied by an amplifier, and they draw more dynamic electricity and cause the amp to work harder. Conversely, high-impedance speakers are easier to drive because they draw less power.

If you 2x the power (1W to 2W for 8 ohms), that boosts the speaker’s loudness by 3 dB; if you do 10x the watts (1W to 10W for 8 ohms), that increases the loudness by 10 dB. Also, if you go double as far away (1m to 2m), you lose ~4 dB.

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Sometimes, the room a speaker is in can add some sound pressure, but we never like to depend on that when choosing speakers. So instead, we assume the only sound we hear is coming directly from the speaker. 

A typical speaker has dispersion in all directions. It does not matter how wide. The sound spreads twice as wide and twice as high at double the distance. This lowers the sound pressure by about 6 dB every time you double the distance. 

An actual line array system is a bit different and complicated, so I’ll stick with a point source here. 

You may find a speaker that can endure three times the power but is 6 dB less efficient. Oops, you just lost level and are paying a lot more on amps.

An example for easier understanding

  • Let’s say the speaker is rated at 110 dB @ 1w/1m.
  • This means that 110 dB is just 1 meter away. 

Just 3 dB more speaker efficiency increases as much volume as doubling the amplifier power. 

If the listener is 4 meters away, we double the distance twice – one meter to 2 meters, then 2 meters to 4 meters. And because we’re doubling the distance twice, we’re losing 12 dB (3 dB x 2 x 2).

Going out to 8 meters, which is pretty far (twice far), you only lose another 6 dB. 

So we are down to 98 dB at the listening position at 4 meters or 92 at 8 meters.

Since some of the dispersion will bounce off stuff and hit the listener, you should always be able to get a bit louder than this calculation, but it is a helpful starting point.

Sensitivity is Generally the Most Important

The speaker’s sensitivity indicates how many decibels of sound pressure the speaker produces at a 1-watt impact at a distance of 1 meter.

There is a significant difference in how loud various speakers play at the same setting on the amplifier. 

Some speakers, such as my favorite from Cerwin-Vega (Amazon link), are very sensitive and thus don’t need much power to play loudly.

The sensitivity of most speakers for everyday home use is in the range of 85–93 dB. 

It is a typical misconception that small speakers are effortless to drive for the amplifier. In fact, it can be just the opposite, as you often sacrifice some sensitivity to get small speakers to play bass.

As with any other spec, please don’t put too much importance on sensitivity, as high sensitivity is no indication of quality. Often, high sensitivity is achieved at the cost of the frequency range.

Although sensitivity itself doesn’t say anything about sound quality, you can benefit greatly from this specification if you plan to play very loud. 

As mentioned earlier, a 3 dB increase in loudness requires doubling the power supplied. Conversely, this means that if two speakers have a 3 dB difference in sensitivity, one will play twice as loud (in measured value) at the same number of watts.

As I wrote in the article on How Many Watts is a Good Subwoofer:

Wattage has very little to do with loudness, but louder sounds require much higher power (wattage). 

It can cost a ton to go from a 100-watt amplifier to a 200-watt, and you can gain the same by selecting a speaker with 3 dB more sensitivity. 

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Here it can be worth reading the specs, so if you’re a sound freak, you should first look at the sensitivity.

But even if a large speaker has a high sensitivity, it can still require lots of watts to play well. Namely, considerable amounts of power are necessary to control the large elements precisely.

Does Adding More Speakers Increase Overall Loudness?

For example, if you have one speaker pumping the sound at 10 dB at a 2-meter distance and add another speaker at the same volume and same distance, will this double the volume?

Let’s just put it like this: 

If you push me in the chest with one hand, that is a certain amount of force. If you push me in the chest with both hands, each pushing as hard as you did with one hand, I’ll feel more power.

This is precisely what happens with sound coming from a set of speakers. 

Yes, adding more speakers increases loudness. This is because each speaker vibrates the air. So more speakers, each playing the same material, and lined up correctly, will mean you experience more ‘volume’ overall.

A side note regarding decibels in general: try not to think of them as a single measure of volume. Without a lot of extra detail provided, they are almost meaningless.

If we have a speaker outputting 70 dB and add another speaker outputting 70 dB, the volume will be 73 dB. With decibels, when doubling the volume, we add 3dB.

Decibels aren’t a linear scale – they’re a logarithmic scale.

In a linear scale, multiplying the number by two multiplies the quantity by 2 – for example, going 120 mph is precisely twice as fast as 60 mph.

In a logarithmic scale, addition translates to multiplication. Specifically in decibels, increasing the volume by 10 dB gives you a volume that is ten times louder – so, for example, 80 dB is ten times louder than 70 dB, and 70 dB is ten times louder than 60 dB.

Decibels signify a ratio between two power quantities, using the formula L = 10*log*10(P1* / P*0), where P0* and P*1* are the two quantities. 

When you add a second speaker with the same volume, you effectively double the loudness, which means P*1* / P*0* is 2, so L = 10log*10*2 = 3 (approximately). So when you 2x the volume, you add 3 decibels.

Aside from the decibel measurement, you must ensure that if you add speakers, they are amplified correctly. One signal traveling through one amplifier (unless bridged over separate channels) to two different speakers will evenly split the amplification between the two speakers.

How Loud Can Your Speakers Get?

A well-developed speaker should be able to endure 86 dB without audibly distorting. An excellently designed speaker should be able to take 96 dB without doing the same.

86 dB is so loud that maintaining a conversation with somebody right next to you would be hard. On the other hand, 96 dB is nightclub loud, and you’re not going to be able to have a conversation at all.

  • Install an SPL app on your phone that measures dB. 
  • Then play your speakers at 65 dB, 75 dB, 85 dB, 95 dB, etc., until just before your speakers show just the start of harshness (this is the onset of clipping, and don’t go beyond that, you could blow a driver). 
  • Take note of how loud each level was, what was comfortable, try different music that you know well, what was electric or just meh, etc.
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Congrats, you’ve calibrated your hearing to a regular scale! You can now figure out the listening volume you like or dislike, the limit of your hearing vs. what your system is competent of at the upper limit.

Also, way before the sound starts clipping, the soundstage and tone start hardening/compressing; note what volume level that is, and just below that is the sweet spot for most people, the most natural sound you can obtain from your rig.

There isn’t a way you can control that directly through your PC without some external measurement system.

Here is the glossed-over easy way if you don’t want to get too technical:

Go to Amazon, App Store, etc., and get an SPL meter. SPL meter by Studio Six on the iTunes store is a good one, but most are close or close enough for what you need to do. 

That is something you ought to do regardless of any approach.

If you want to set an easy limit:

  1. Turn your volumes to the max and adjust your amp/pre-amp/volume out on your PC until the signal coming out of the speakers is the desired level.
  2. Use a “master level” volume control, such as the pre-amp knob, amp knob (if it has one), or system volume.
  3. NEVER TOUCH THIS DIAL.

Since you should be playing a track or file with 100% signal volume, this will be the loudest your speakers will ever get.

There is no flexible way to do this with computer software because there are far too many variables for a compelling piece of software between speaker size, amplifier power, room size, source signal, room absorption, etc., to do without doing something costly (i.e., industrial calibrated tools that cost into tons for each piece and only work with each other). 

For the more technical folks: yes, this won’t work precisely as different frequencies will have different responses, but this is a decent enough approach.

TLDR: Go to Amazon and purchase an SPL meter. They are inexpensive; your ears will like you.

Let’s Talk Science to Conclude

From an engineering standpoint, there is a set of interrelated parameters known as the Thiele/Small Parameters that define the performance of a speaker at low frequencies in a given environment. 

It has to do with the cone size, how far the cone can travel, the material properties of the cone and suspension, etc.

Loudness, or – the maximum output (I’m using this term since “volume” also refers to the amount of air the speaker can move) of the speaker, is the point at which the voice coil reaches the end of its suspension travel, or the cone starts to deform from its resting shape.

Two things determine how loud a speaker is: its surface area and excursion (how far in and out it travels). 

But excursion is a function of many other variables: the moving mass of the speaker, the voltage used (that’s your amplifier), and motor strength (the magnet + current through the voice coil). 

The excursion is also determined by the length of the coil in the magnetic gap, the suspension (which delivers a restoring force to bring the diaphragm back to its resting position), and the approval from the voice coil to the back plate. 

Also, motor strength is related not only to the magnet used but also to the geometry of its construction and the total number of windings in the coil. Adding more windings increases strength, but it adds mass and impedance.

Tray Fiddy

Tray has come to terms with the fact he will probably never be a famous DJ.... but that hasn't stopped him from mixing and researching audio equipment. Tray has over 12 years of experience DJing at home and events.

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