Basic frequency detection similar to graphic EQ
I searched for this but found answers more complicated than I think it should be. I'm just looking for a starting point/ best approach to this...
I'm looking to get separate frequency band information from an audio signal, (ie. breaking it up into the respective levels of the different frequency bands). I would like this frequency info along the lines of what a basic graphic home stereo visualizer eq would be receiving to make it's bars jump up and down. But instead of the graphics, I am aiming for the data to translate into something like sliders (or 0 to 1.0) instead.
I found a post on here stating there is delay on frequency detection objects. I need something without delay (or as little delay as a home stereo graphic eq visualizer might have = none perceivable). The goal with this is to divide incoming audio into frequency bands whose data will then independently trigger other samples according to frequency.
the delay is when they use fft. one could do a very small fft but thats not nice for
accurate analysis.
you should just build it like you would biuld an EQ, for example using biquads.
or even [fffb~], for a start.
then measure the rms of the individual bands and convert to numbers.
it should be fine to downsample the whole thing for /16 in order to save CPU.
Quick and easy start: A bank of reson~s spaced in frequency as for a graphic eq.
Thanks spectro, just what I was looking for. Reson~ is nice.
Wondering though, what's the *~-1 after the cycle for?
As it is , nothing. Though I was originally using adc~ in to check the patch, so a standby gainer/attenuator in case input levels were too low for the graphic display. But its also a good way to feed any "bank" in general as it means its far quicker to changing the gain settings - or input source - than for each reson~ in turn.
hey spectro,
I just wanted to have a play with that reson~ patch. How can i load that text into max msp?
The bank of reson~s in the patch above could also be replaced with:
[ fffb~ 7 125. 2. 23. ]
7 filters
125 (Hz) is the lowest frequency
2 is the multiplier for each successive filter
23 is the Q you have those reson~s set to
cheers,
Leigh