Sensitivity tells you how much volume you’ll get from a speaker with a given amount of power.
Not only can it affect your choice of speaker, but also your choice of stereoreceiver/amplifier.
What Sensitivity Means
Speaker sensitivity is self-explanatory once you understand how it’s measured.
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Now observe the results, measured indecibels (dB), on the microphone or SPL meter.
That’s the sensitivity of the speaker.
For example, some speakers have a sensitivity of around 81 dB or so.
This means with one watt of power, they’ll deliver just a moderate listening level.
Want to hit some nice and loud 102 dB peaks in your home theater system?
You’ll need 128 watts.
Sensitivity measurements of 88 dB are about average.
Anything below 84 dB is considered rather poor sensitivity.
The sensitivity of 92 dB or higher is very good and should be sought after.
Are Efficiency and Sensitivity the Same?
You’ll often see the termssensitivityandefficiencyused interchangeably in audio, which is ok.
Most people should know what you mean when you say a speaker has89 dB efficiency.
Technically, efficiency and sensitivity are different, even though they describe the same concept.
Sensitivity specifications can be converted to efficiency specifications and vice-versa.
Efficiency is the amount of power going into aspeakerthat is actually converted into sound.
Unfortunately, sensitivity measurements can be performed in a variety of ways.
you’ve got the option to measure sensitivity with pink noise.
Pink noise also doesn’t permit much in the way of limiting measurement to a specific band of audio.
But that’s added work.
Many prefer to evaluate sensitivity by taking on-axis frequency response measurements of speakers at a set voltage.
Then you would average all the response data points between 300 Hz and 3,000 Hz.
This approach is very good at delivering repeatable results with accuracy down to about 0.1 dB.
But then there’s the question of whether sensitivity measurements were done anechoically or in-room.
An anechoic measurement considers only the sound emitted by the speaker and ignores reflections from other objects.
This is a favored technique, being that it’s repeatable and precise.
However, in-room measurements give you a more real-world picture of the sound levels emitted by a speaker.
But in-room measurements typically give you an extra 3 dB or so.
What Does This Have to Do With Soundbars and Bluetooth Speakers?
It would be nice to see sensitivity ratings for the speaker drivers used in these products.
That would be a pretty satisfying level for gaming and action movies!
And that’s not really loud enough for anything more than casual TV watching.
And eight watts of power is far less likely to push the drivers past their limits.
A wattage rating does not.
Here’s another example.
Clearly, wattage doesn’t tell the story here.
It doesn’t even come close.
This is what happened with the CEA-2010 standard for subwoofers.
Is Sensitivity Always Good?
You may wonder why manufacturers don’t produce speakers that are as sensitive as possible.
It’s typically because compromises need to be made to make it achieve certain levels of sensitivity.
For example, the cone in a woofer/driver could be lightened to improve sensitivity.
But this likely results in a more flexible cone, which would increase overall distortion.
So it’s aspects like these that manufacturers have to balance out.
But with all things considered, choosing a speaker with a higher sensitivity rating is usually a better choice.
You may end up paying a little bit more, but it will be worth it in the end.
