Powerful underwater speaker

[Fatal926]

For many years, we have been using a homemade underwater loudspeaker at our base to entertain and notify divers. We simply put a powerful speaker in a pressure cooker, installed ip68 cable gland in the lid and connected the wire to an amplifier on the shore. The pressure cooker is at a depth of 5 meters, the speaker power is 50 RMS, the amplifier power is 25 RMS. The speaker was loudly audible underwater at a distance of 30-50 meters, weakly audible at a distance of up to 100 meters.
This year, we replaced this speaker with a 50-watt vibration speaker and received an incredible increase in volume. Now music or our voice commands can be clearly and loudly heard at a distance of 450 meters on the opposite shore.
I do not propose to pollute all the seas and lakes with loud sounds, but I want to share an economical technical solution that competes in efficiency with expensive specialized systems and it can be useful for various purposes.
For example, in our case, we transmit voice commands during underwater sports events, repair work, etc. Also, some experienced divers quite accurately indicate the direction of the sound source and use it for underwater navigation.

Good morning, I saw your message about your DIY sound signal with a pressure cooker. I'm an underwater hockey player and I'm looking to make a loud enough sound signal to play. Can you tell me more about your system? What is its overall manufacturing cost? Do you think it could have several different tones?

 

[shenzhen]

Good morning, I saw your message about your DIY sound signal with a pressure cooker. I'm an underwater hockey player and I'm looking to make a loud enough sound signal to play. Can you tell me more about your system? What is its overall manufacturing cost? Do you think it could have several different tones?

Good morning, we do not transmit alert tones, but simply speak into the microphone and the divers clearly hear the commands even when exhaling. We also turn on music and the sound quality is very good, without wheezing and distortion. So I am sure that any sound tones will also be reproduced very loudly and with high quality.
As for the cost of all the parts:
A wide-range vibration speaker from Aliexpress costs about 75 euros (depending on delivery).

80W-15W Full Range Vibration Lautsprecher Anti-neighbor Audio Tragbare Lautsprecher Vibro Resonanz Bass Sound Erreger subwoofer - AliExpress 44

Smarter Shopping, Better Living! Aliexpress.com

de.aliexpress.com

As an amplifier, we use a powerful car radio with a nominal power of 25 watts according to the specification (the measured average maximum is about 80 watts), we do not turn it on at full power, I think about 50 watts. And although the vibration speaker heats up to about 50 degrees, it has been working great for more than six months. The radio was bought a long time ago and I don't remember the price.
The only direct costs left are the pressure cooker and thick wire. We bought the pressure cooker at a sale for $30, and took a regular cable for electrical wiring.
If I were you, I would buy only a vibration speaker and test the result with any pressure cooker and an available amplifier before buying anything specifically for this project. The speaker is simply glued to the pressure cooker with hot glue and even if you don't like the first pressure cooker you come across, it will remain undamaged.

 

[tursiops]

I'm intrigued that the positive responses to this Russian OP have been from China and France, but only negative responses from the US.

 

[shenzhen]

As a developer and manufacturer (scubaprintedparts.com) I correspond a lot with divers from the USA and have never, not once, encountered a negative attitude because of the country of residence. As for this topic, of course, there are many people who do not agree with music underwater and I understand them perfectly. We are improving our reservoir, because it is just a large quarry and underwater is not as interesting as in the sea, but even our visitors sometimes ask to turn off the music
But as an engineer I wanted to share a technical solution.

 

[tursiops]

As a developer and manufacturer (scubaprintedparts.com) I correspond a lot with divers from the USA and have never, not once, encountered a negative attitude because of the country of residence. As for this topic, of course, there are many people who do not agree with music underwater and I understand them perfectly. We are improving our reservoir, because it is just a large quarry and underwater is not as interesting as in the sea, but even our visitors sometimes ask to turn off the music
But as an engineer I wanted to share a technical solution.

As an engineer, I was only sharing my observation, which was not intended to be a comment on the country of origin, but rather hinting at possible cultural differences in the value of silence underwater.

 

[scubadada]

With exception of diver recall, I don't want to hear a speaker underwater