What is a directional speaker? | How does it work? | Detailed explanation

directional speaker

Friends, imagine you are watching TV with full sound in the middle of the night in a crowded house — or listening to your favorite music at full volume from your music system. But no one is coming to tell you to turn down the volume of the TV, or the neighbor is having no problem — because surprisingly no one can hear this sound except you (just like Zeno headphones!). What? Sounds like a joke? But to be honest it is possible. And this completely amazing thing can be done by a new type of loudspeaker — which is known as a directional speaker.

Any ordinary speaker can spread any sound around by pumping in the air. But directional speakers can send sound by targeting a certain direction so that only a certain person can hear that sound. But now the question is, how does this speaker work? Let’s find out.

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Directional Speaker

Directional Speaker

A conventional speaker is specially designed to propagate sound over a wide area — where a speaker has a plastic or paper spout that continuously produces sound by pumping air from front to back and spreading it around a wide area. The more electric current that can be transmitted in ordinary speakers, the more sound can be generated from it. Giant speakers are used in any big festival, so that the sound can be spread over a large area.

Most of the time we expect these things from a normal speaker. But a lot of times if the sound can be reached in a certain direction with a speaker, it can become more useful. Suppose, you are a captain of a giant warship and you are sailing the sea. But a small fishing boat came in front of you and it is right in the middle of your path. You are trying to reach the warning by radio but no response is coming. In this case, you can send warnings using directional speakers. When a sound is generated with a normal speaker, it moves around, so it cannot travel long distances. But a directional speaker can throw sound in a certain direction and at a certain distance. In fact, it can also be called the flashlight of sound.

How do directional speakers work?

Directional speakers work in a completely different way than any ordinary speaker. The biggest difference between a directional speaker and a normal speaker is that it does not produce sound through any moving electromagnetic coils and splinters of paper or plastic. It produces ultrasound which is very high frequency sound waves. Usually people never hear this sound. So how do these speakers work?

See, friends, we all learned in the ninth-tenth grade that the range of human hearing is from 20 Hz to 20 kHz (20,000 Hz). That means we will never hear any sound above 20 kHz. Any normal speaker produces sound from 20 Hz to 20 kHz which we can hear very comfortably. However, directional speakers are equipped with a number of piezoelectric transducers, which generate many high-frequency sound waves, and these sound waves are about 200,000 hertz.

Now, this is 200,000-hertz frequency but your voice is not sent to hear. This is a major frequency, which helps to send sound in certain directions and at certain distances. In fact, this speaker transmits an ultrasound of two different frequencies simultaneously. One frequency contains a specific 200,000 Hz signal — and the other frequency fluctuates the signal from 200,200 Hz to 220,000 Hz. Now if these two different sounds get stuck somewhere along the way (like with your curious head), these two sound waves automatically merge with each other and subtract from each other to create another new sound wave, which is 200 Hz to 20000 Hz — and your ears can easily hear it.

Suppose you have a directional speaker in front of you, and then a message is thrown at you. However, it will send two types of frequency ultrasound together. The first will be 200,000 Hz (which is regular ultrasound), the second will combine ultrasound with the original audible sound, meaning ultrasound of any frequency between 200,200 Hz and 220,000 Hz. Now when these frequencies collide with you, the frequencies will be mixed and subtracted from each other. Now suppose you were sent a message with a frequency of 15,000 Hz. Then the first wave will be 200,000 Hz and the second will be 215,000 Hz. Now subtracting them, the answer would be 15,000 Hz. Now you can comfortably hear this sound.

Use of directional speakers

What is the refresh rate?

Friends, directional speakers are not a newly invented technology. We have discovered this long ago. But it is not yet available to the general consumer. However, it may be used by ordinary consumers in the future. The use of this speaker can go to a limitless level if you think about it professionally.

Remember, if the ad posters in the market only talk to you, when you walk by it. When you go in front of an object in a museum or in front of a painting, they will tell you their own story, they will start telling it to you in front of another, and so on. You can send a specific message to a specific person even in the midst of loud noise.

The US military has been using directional speakers since 2004. Moreover, directional speakers are used in the Navy, various warships, and some other large sectors. You may also have a directional speaker on your TV the next day, so you can enjoy the full volume without disturbing anyone.


So friends, this was today’s topic. I hope you all enjoyed it. But don’t forget to share your thoughts on the possible future use of directional speakers.

Sabik Al Mahmud

There was a fascination with technology from a very young age, and perhaps that fascination is a little more than other ordinary people. From Nokia's button phones to infinity display bezel-less smartphones, everything is my favorite. Technology has never been more impressive in my life. And writing started with an interest in this technology .....

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