Octopush Buzzer System - Failed, Try Again
Well, I started writing about a buzzer system for Octopush that I put together last week. The idea being that the ref on the side of the pool can press a button to stop play (eg for goals, fouls, time etc) resulting in a sound underwater that all the players can hear. Fortunately, I decided not to post it until I'd tested it. The good news is that the underwater part seems to be waterproof. The bad news is that you need to be right next to it to hear it.
So, back to the drawing board. Unfortunately, the waterproof sounder unit I made is kind of permanently sealed, and as all the sound generation was sealed inside, I'm going to have to try and open it up again to change it, and then see if I can re-seal it. This time I'm off to research underwater sound propogation and the frequency response of water to sound - Gareth Ayres suggested trying lower frequencies. I'm also going to see if I can tune the acoutsics of the speaker output to the container it's housed in, hopefully to generate resonance and better propogation from the sealed unit into the water, and/or coupling the speaker (currently a part of a two-tone piezo siren unit) directly to the outer case. Failing that, I need something even lounder (I picked the one I'm using as it's rated at 105dB @ 1m)!
