For many speaker designers, the speaker frequency response is considered the most important characteristic of a speaker.
Speaker frequency response is the measure of a speaker’s ability to reproduce different frequencies or pitches. It is usually measured in Hertz (Hz) and is expressed as a range, such as 20-20,000 Hz.
Typically, by looking at a speaker frequency response curve, you can determine how well a loudspeaker is reproducing sounds.
If there are dips or peaks in the frequency response, this might indicate some poor performance in this frequency range.
In this article, we will look at what speaker frequency response is, why it matters to speaker users and speaker designers, and how to read speaker frequency response curves so you can understand them.
What Does The Frequency Response Of Speakers Mean?
Speaker frequency response is the measure of a speaker’s ability to reproduce different frequencies or pitches. It is usually measured in Hertz (Hz) and is expressed as a range, such as 20-20,000 Hz. This number tells you how low and high the speaker can play sounds.
A wider range indicates that the speaker can reproduce more sounds, while a narrower range means that the speaker is limited to reproducing only certain frequencies.
The human ear can hear a wide range of frequencies, from 20 Hz to 20,000 Hz. However, we don’t perceive all frequencies equally.
For example, low frequencies (20-250 Hz) are responsible for the “thump” of a kick drum, while high frequencies (20,000-40,000 Hz) are responsible for the “sizzle” of a cymbal.
Midrange frequencies (250-5000 Hz) are where most of the action happens in music, and this is where speakers tend to have the biggest impact on sound quality.
When shopping for speakers, you’ll want to pay attention to the frequency response rating. This will give you an idea of how well the speaker can reproduce different frequencies.
A wider frequency response means that the speaker can reproduce a wider range of sounds, while a narrower frequency response means that the speaker is limited to reproducing only certain frequencies.
When designing speakers, you will want to produce a frequency response that matches the customer’s specifications. For example, if you are designing a compression driver speaker that is intended for use in the 8kHz plus region, you will want to ensure that the frequency response is loud and ideally flat from this region up with no peaks or dips.
In reality, this is impossible as the frequency response of a high-frequency compression driver will always peak and dip, but you do not want any peaks or dips that are too sharp.
What Is A Good Frequency Response For Speakers?
In a perfect world, the frequency response curve of a speaker will be completely flat. This would indicate that the speaker can produce the frequencies perfectly, with no peaks or dips and at a constant volume.
It would tell us that the speaker can reproduce music that sounds identical to the way it was recorded, with perfect balance without any great volume changes.
In reality, a perfectly flat curve is not possible, but we can accept a “bumpy” curve as long as it does not have any significant peaks or dips.
In addition, all speaker curves will have a frequency range of operation. It is not possible to have one speaker that can reproduce frequencies across the entire frequency spectrum perfectly, i.e. from 20Hz to 20kHz.
This is why we have sub-woofers, bass drivers, mid-range drivers and high frequencies drivers and use a combination of speaker types to create the best overall sound.
For example, the following high-frequency single speaker from B&C Speakers is designed for operation in the 1kHz to 17KHz range.
Although the x and y-axis labels are a little hard to see, we have frequency on the x-axis and dB on the y-axis.
We can see that between 1kHz and 17kHz, although the response curve is “bumpy” it is still fairly consistent, with no major dips or peaks. The sound profile of this speaker will produce sound well in this frequency range, which is what it is designed to do.
Below 1kHz, this speaker will not produce a good sound.
Is Higher Frequency Response Better For Speakers?
A high-frequency response is not better for speakers. The best frequency response is a smooth and flat frequency response, which will show that the speaker can reproduce sounds well within a given frequency range.
Often you will be given a number, something like this, for example:
Linear frequency response: ± 1.5 dB (45 – 20,000 Hz)
This frequency response number is taken from the Genelec 8341 AP studio monitors.
This tells us that over a frequency range of 45Hz to 20kHz (which is excellent), the frequency response of this speaker will deviate from the nominal by ± 1.5dB. This is really excellent.
This speaker should be able to reproduce sound very accurately across this frequency range, which is nearly the full frequency band.
What Is A Good Frequency Response For Car Speakers?
To get the best sound possible from car speakers, you want to cover as much of the audio frequency range as possible. The audio frequency range is between 20Hz and 20kHz.
In reality, deep bass will be around 30Hz, and the very high-frequency sounds will be in the 15kHz plus range.
It is very difficult to do this full range with just one car speaker, so you will need at least two speakers if you are looking for this full range. So you have a larger speaker to deal with the lower bass frequency sounds and a smaller speaker to deal with the higher frequency sounds.
In addition, if you have the space, you can use a third car speaker that covers the mid-range frequencies so you have the full audio spectrum from low bass to mid-range guitars and vocals, to high-frequency instruments covered.
Just like picking any speaker, as explained previously, you want the frequency response of your speakers to be as smooth as possible, with little deviation. This will tell you that the speakers can produce sound accurately with no big peaks or dips in the sound.
Why Is Frequency Response So Important?
The frequency response of speakers is so important as it tells us how well a speaker can reproduce sound. At the end of the day, that is the purpose of the speaker, so it is essential that speakers can reproduce the recorded sound as accurately and as true to the original recording as possible.
A speaker with a wide frequency response range can reproduce more sounds, while a narrower range means that the speaker is limited to reproducing only certain frequencies.
This is important for you to know as a speaker designer or a buyer, as if you love your bass, you need to ensure that your speaker is designed to cover the bass frequencies.
Similarly, if you love your vocal range in music, you need to ensure that your speaker can reproduce sound accurately in this range.
Knowing the frequency response of different speakers, we can match up different speakers to cover the entire frequency range in one sound system to create a fantastic listening experience.
Does Speaker Frequency Response Define Speaker Audio Quality?
No, speaker frequency response does not define speaker audio quality. Speaker frequency response is the measure of a speaker’s ability to reproduce different frequencies or pitches.
Speaker audio quality comes from other factors in the speaker design, such as the speaker design, material quality and build quality.
Final Thoughts
Frequency response is an important spec to look for when purchasing new speakers, as it tells you how well the speaker can reproduce sound.
A good frequency response should be relatively smooth, with no large peaks or dips in the sound. This will ensure that the speaker can produce sound accurately and faithfully to the original recording.
However, frequency response alone does not define speaker audio quality – other factors such as speaker design, material quality and build quality also play a part.
When considering which speakers to purchase, be sure to look at the frequency response spec alongside other specs in order to make an informed decision.
