uranium_jones
Well-known member
Hi everyone. Long time, no see. But I have only now got my soldering bench back in place after more than 6 months of medical and construction hell.
I'mma cut to the chase: I need to make an ultrasonic white noise speaker system, omnidirectional as can be and with a frequency range of maybe 12-15 kHz on the low end, and sky's the limit on the high end. This will be to excite an interior space only with broadband high-frequency content The joys of working in a scientific field!
I have come here because I don't know of any better collection of electrical-engineering-and-audio-adjacent people on the internet.
So here's what I have so far:
1) https://circuitdigest.com/electronic-circuits/simple-white-noise-generator-circuit-diagram - This seems like a simple way to get some white noise going, although I don't like the requirement for so much voltage on the power supply. 9-18V would be better. Maybe there's a way I could use some sort of charge pump? But I don't know about that. Anyway, I figure a simple high-pass filter should cut frequencies below... let's say 14 kHz because I think that's how high I can hear, and I don't want this to get annoying.
2) These piezo drivers seem like they will do the trick: https://www.amazon.com/gp/product/B08SLZBKCH/ - Maybe I need to order 4 to shoot sound in 4 directions and be pseudo-omnidirectional? Radiating in a hemisphere would do fine.
3) It's tricky to try and find cheap amplifiers that will definitely go above 20kHz. This one seems to do it though: https://www.amazon.com/gp/product/B0087318VC/ - I don't need a flat frequency response above 20 kHz, but I don't want someone to have put in a lowpass filter.
Wish List:
- a protoboard circuit design that will give me everything I need in one circuit: connection to a DC power supply jack, the white noise generation circuit, an on/off switch, a volume pot, connection to the amplifier, power and signal lines to the amplifier (Can I run the white noise source and the amp on the same PSU?)
- general purpose recommendations on things to watch out for.
Sorry that this is entirely out of left field, but it's good to be back on the forum.
I'mma cut to the chase: I need to make an ultrasonic white noise speaker system, omnidirectional as can be and with a frequency range of maybe 12-15 kHz on the low end, and sky's the limit on the high end. This will be to excite an interior space only with broadband high-frequency content The joys of working in a scientific field!
I have come here because I don't know of any better collection of electrical-engineering-and-audio-adjacent people on the internet.
So here's what I have so far:
1) https://circuitdigest.com/electronic-circuits/simple-white-noise-generator-circuit-diagram - This seems like a simple way to get some white noise going, although I don't like the requirement for so much voltage on the power supply. 9-18V would be better. Maybe there's a way I could use some sort of charge pump? But I don't know about that. Anyway, I figure a simple high-pass filter should cut frequencies below... let's say 14 kHz because I think that's how high I can hear, and I don't want this to get annoying.
2) These piezo drivers seem like they will do the trick: https://www.amazon.com/gp/product/B08SLZBKCH/ - Maybe I need to order 4 to shoot sound in 4 directions and be pseudo-omnidirectional? Radiating in a hemisphere would do fine.
3) It's tricky to try and find cheap amplifiers that will definitely go above 20kHz. This one seems to do it though: https://www.amazon.com/gp/product/B0087318VC/ - I don't need a flat frequency response above 20 kHz, but I don't want someone to have put in a lowpass filter.
Wish List:
- a protoboard circuit design that will give me everything I need in one circuit: connection to a DC power supply jack, the white noise generation circuit, an on/off switch, a volume pot, connection to the amplifier, power and signal lines to the amplifier (Can I run the white noise source and the amp on the same PSU?)
- general purpose recommendations on things to watch out for.
Sorry that this is entirely out of left field, but it's good to be back on the forum.
