Help needed with electronics side of design

Thread Starter

Oroku saki

Joined Jul 13, 2020
Hi there, I am currently working on a project that requires a waterproof subwoofer speaker (8 ohm) be hooked up to either a sine wave generator or a laptop/computer of some sort, this is because I want to be able to play frequencies and generate tones such as resonants and sweeps etc. So I’m thinking maybe a computer might be better than a sine wave generator as I’m sure you can just download a sine wave generator onto one anyway (please correct me if this is wrong). The basics of the project is to have a waterproof subwoofer speaker installed into the bottom of a crystal clear plastic pail/bucket then to place water and another medium such as glitter or dyes into the pail and then generate tones, my hope is that the glitter or dyes will make visualising what is going on in 3D space easier when sound is being generated by the speaker. I’m sure your all familia with the chladni plate experiment, this would be similar but instead of a flat plain you would be able to see the sound in three dimensions and maybe I can find those frequencies that spontaneously order the grains into patterns like in the Chladni Plate experiment but in 3D. So please can someone help me by pointing me in the right direction in regards to what I would need to connect the speaker I have to either a sine wave generator or a computer? This is my first post on this forum so please bare with me if this is a bit long winded or not listed in the right place. Thanks all


Joined Jul 10, 2017
The simplest solution for you would be to use a computer or laptop and an audio amplifier connected to your speaker. Do you have an old analog amplifier or tuner amplifier? Maybe a friend or relative has an old one laying around that they would like to get rid of. If not you can probably pick up an inexpensive one from a second hand store. You only need a few watts output to do what you are suggesting.
Connect the audio output to one of the auxiliary input channels of the amplifier. Connect your speaker to the output of the same channel. When you first switch on, do it with the volume control set at minimum so you don't damage your speaker.
Here is a site where you can download test tones for no charge:


Joined Jan 15, 2015
Interesting project. I would use a computer or laptop and some nice free software like Audacity for tone generating. I use Audacity and it is nice software, will do what you want including a sweep function. There are also dozens of online tutorials. Your next step is determining how much power you want to drive your speaker with.



Joined Aug 7, 2008
Rather than a waterproof subwoofer speaker, might try an "Audio Tactile Transducer" like Spa-TM
by PQN Audio. Max. power 20W, 8 Ohm. These are meant to be mounted to something like a wall to turn the wall into a speaker.


Joined Jan 23, 2018
The very real challenge will be the weight of the water creating a bias force on the speaker. I have seen that video where they put fine sand on the steel plate and sweep the frequency, showing the vibration patterns.
There are two things here, the first is that the water will be a considerable force load against the driver, unless driver and tank bottom are separate things. The other thing is that it will take a lot more force to vibrate the bottom of any sort of water filled container. And any material that is flexible will tend to not resonate nearly as well as that steel plate in the video. In fact, you will probably not see much of a resonant pattern at all.


Joined Jan 23, 2018
" You are ignoring content by this member" ????
I read the description of how the "Spa 1M"s so wonderful but there is not one word that tells me that it would be able to transfer vibration to a plate . It claims to be an underwater speaker of some kind, with not one word of detail. So I doubt very much that it would achieve the results desired by the TS. Thus it was indeed ignored.


Joined Sep 17, 2013
I also have doubts about the suitability of a subwoofer speaker for vibrating the bottom of the pail or the pail contents. Considering the pail dimensions and the wavelengths involved in forming any patterns I think the necessary driving frequencies would be above the subwoofer's efficient response range.