so, in dead of night when outside has low ambient noise, from inside i can hear a low level (faint) hum, in the range of 250Hz. any ideas to build a simple directional detector that 1) can detect the frequency, and 2) allow me to get an idea as to the direction the sound is emanating from. i suspect the sound is coming from a nearby pool pump, but would be neat to build a detector that can help solve the mystery (and stop annoying me).
since i am working another project that may use piezo element, how about mounting a bare piezo element to a 1/2" thick vertical AL plate or wood with heavy base, couple that to a high gain opamp? just not sure if 250Hz would couple well to a piezo element, might get ran over by noise in the gain. i guess one side of piezo should be on heavy mass while the other side couple to a "fork" that has resonance down low near 250Hz?
your thoughts?
since i am working another project that may use piezo element, how about mounting a bare piezo element to a 1/2" thick vertical AL plate or wood with heavy base, couple that to a high gain opamp? just not sure if 250Hz would couple well to a piezo element, might get ran over by noise in the gain. i guess one side of piezo should be on heavy mass while the other side couple to a "fork" that has resonance down low near 250Hz?
your thoughts?
Last edited: