How to make a filter?
I need to make a filter that takes 35kHz signals and makes them audible to humans (20khz). I have no idea where to start
I need to make a filter that takes 35kHz signals and makes them audible to humans (20khz). I have no idea where to start
Anonymous
Favorite Answer
You need band pass filters to get rid of the side lobes (frequencies) for pure 20khz from 35khz. Bats can hear 20khz and small human children can but I know of no adult human that can hear that. After all of the filtering and pre-amps, you need a final amp and a tweeter speaker. I bet dogs and cats can hear it.
amania_r
How wide is the signal at 35KHz? If say just a few KHz, then you can multiply (modulate) with say a fixed 30KHz signal (carrier) and pass the result through a say 10KHz low-pass filter. A 35KHz signal would come out as a 5KHz tone, a 37KHz input would come out as a 7KHz tone.
To prevent aliasing errors, you should pass the input signal through a 30KHz to 40KHz bandpass filter first.
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ANY HUMAN COULD NOT ABLE TO HEAR MORE THAN 15KC ! YOU ARE WASTE OF TIME TO TRY THAT. SIMPLE FILTER IS LC FILTER.