High Frequency Speaker

[Mansour_M]

Hi Everyone,

I am working on a project in which I need to produce acoustic waves in range of 20KHz to 80KHz. The main problem here, is to find a speaker able to generate such wave.
First of all, Is there such speaker? If yes, please guide me. Thanks in advance.

 

[chuckey]

There is a speaker called an ionophone (or similar). It works with out any moving parts by modulating a high voltage discharge with the audio. The actual air pressure is generated by the electro static discharge so in principle there is no high frequency limit. One possible disadvantage is the requirement for lots of audio voltage - 600V? which was done with a transformer which in your case would have to be optimised for your unusual frequency range (normally 3-22 KHZ).
Frank

 

[zrmotoring]

Dogs will love this frequency.

 

[Mansour_M]

Thank everyone,

Acctually, "zrmotoring", I want to use for some kinds of birds. However I am not sure about the range of frequency and I need to perform some test to specify the frequency range.

 

[kak111]

Some examples about ultrasonic transducers..................

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Piezoelectric Transducers | Piezo Transducer | PZT Transducers | Ceramic Transducers

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**broken link removed**

 

[FvM]

It should be noted, that all piezo air ultrasonic transducers are resonant small band devices, rarely suited as ultrasonic speakers.

Electrostatic transducers can be basically an option.

There's a profound website about plasma tweeters as mentioned by chuckey, unfortunately only partly in English. It has many descriptions, photos and schematics of commercial systems as well as DIY instructions. Ulrich Haumann's DIY PLASMA TWEETER

 

[dick_freebird]

Any loudspeaker with a piezo tweeter ought to do. I had a
set once, a bit "bright" for my liking but high power handling
(until the woofer suspension foam crumbled from age).

For that matter if you're willing to accept a non-flat frequency
response then dynamic (coil) elements may still do, you could
comp the fading output with an opposing high-pass filter / amp.
You're only talking two octaves up from the usual corner freq
for tweeters, right?

 

[FvM]

Any loudspeaker with a piezo tweeter ought to do.

Unlikely. Did you notice the intended frequency range of 20 to 80 kHz? Many piezo tweeters don't even achieve full sensitivity up to 20 kHz. They mostly have a paper membrane. Some small electrodynamical ring radiators perform better, their sound pressure is considerably higher than piezo tweeters (the price as well), some have output up to 40 even 50 kHz, but with many resonances. The best flat frequency response with moderate SPL is achieved with ribbon tweeters as far as I'm aware of, like the below one: