How to get PD to respond only to certain frequency ranges in terms of using that info for a physical output such as vibrating modules? I am trying to build a device that will use small mics (electret?) as audio receivers then output a vibration based on a certain frequency range being present. I am quite new to PD, willing to learn but lacking in knowledge thus far. Could anyone help and let me know if this is even possible? Essentially, I would like to build a device that triggers a vibration pad when it detects a certain frequency eg 700-900 Hz.
Thanks in advance

check [bp~] (stands for bandpass filter) and [env~]. Your center frequency should be something like 800 and set a Q that allows a 200Hz band (might be wrong in these numbers, not really good with filters). Feed this to [env~] and check its output (it outputs control values, not a signal). You can then use these values with some comparison objects (like [> ] with [change], in order not to trigger continuously while within the frequency band) and [sel 1] (for example) to get a bang when you get such a frequency.
Just an idea..