Mark F
May 3rd 07, 09:37 PM
I need something to allow me to hear the presence of high frequency
sounds.
In particular, I need something to either shift sounds about 10KHz
down or cut their frequency in half.
For example, I want to be able to analyze engine sounds, CRT flyback
sounds, turbulence in water and air flows, etc.
I can't just use an oscilloscope or similar graphics device because
the differences between a good and bad flow is usually too subtle to
see on a video display. (I only need for the device to work at up to
about 22KHz; I don't need it for communication with bats or dolphins,
so I don't need for it to work in the 100KHz range.)
Since I need for the response to be in real-time I can't just find an
analog tape recorder and playback at half speed. (Also, since the
response has to be in real-time there will be frequency palliating.
This is acceptable.)
My budget for the complete device, including microphone, is $300.
I tried Google and found "eConvergence's Belfry Bat
Frequency Division Detector" at
http://njsas.org/projects/bat_detector/01/belfry.html
This might do what I want, but it is do-it-yourself. I want an off
the shelf device.
I also found some MIDI things that might do what I want, but they need
a MIDI studio to work with, which puts it out of my price range.
Does anyone have any suggestions for a specific device or technical
term? (Searching for either "frequency shift" or "frequency division"
didn't help much, since there were too many hits for uses unrelated
to my use [except for the Belfry Bat detector, which I found among
500 other hits.])
Thanks.
due to
sounds.
In particular, I need something to either shift sounds about 10KHz
down or cut their frequency in half.
For example, I want to be able to analyze engine sounds, CRT flyback
sounds, turbulence in water and air flows, etc.
I can't just use an oscilloscope or similar graphics device because
the differences between a good and bad flow is usually too subtle to
see on a video display. (I only need for the device to work at up to
about 22KHz; I don't need it for communication with bats or dolphins,
so I don't need for it to work in the 100KHz range.)
Since I need for the response to be in real-time I can't just find an
analog tape recorder and playback at half speed. (Also, since the
response has to be in real-time there will be frequency palliating.
This is acceptable.)
My budget for the complete device, including microphone, is $300.
I tried Google and found "eConvergence's Belfry Bat
Frequency Division Detector" at
http://njsas.org/projects/bat_detector/01/belfry.html
This might do what I want, but it is do-it-yourself. I want an off
the shelf device.
I also found some MIDI things that might do what I want, but they need
a MIDI studio to work with, which puts it out of my price range.
Does anyone have any suggestions for a specific device or technical
term? (Searching for either "frequency shift" or "frequency division"
didn't help much, since there were too many hits for uses unrelated
to my use [except for the Belfry Bat detector, which I found among
500 other hits.])
Thanks.
due to