audio spectrum low frequency only

adamknifey's picture

Hey guys, I'm new to quartz so I just had a question about the audio spectrum.

Basically at the moment I've plugged my guitar into the line in with an effects pedal and make a few different sprites react to the audio spectrum. The index isn't able to use decimals so I'm limited to 0, 1, 2, 3 etc.. But my problem is the only index's that really react to the guitar notes in normal tuning are 0 and 1. I read that 0 is like 0 - 512Hz. So I basically want to split up the 0 index into say 0-50hz, 50-100, 100-150 etc etc so that its easier to tell the difference between a low note and a high note.

I read

http://kineme.net/forum/Release/Production/KinemeAudioInputWaveformoutpu...

but couldn't get it to work properly. Can anyone tell me how to make a simple example to start with.

Adam

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cybero's picture
Re: audio spectrum low frequency only

See attached example.

There are various ways of dealing with this, using Structure Range to pick out the structure bands one wants to get the data for. One can also use the Audio Processor, which aggregates the values into single Low Mid and High values.

The following forum URLs would prove very educational to you

http://kineme.net/composition/smokris/PrimaryFrequency

http://kineme.net/forum/Applications/AudioVisualizations/AudioSpectrogram

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KinemeAudioExample.qtz46.31 KB

scottbernoth's picture
Re: audio spectrum low frequency only

[http://mansteri.com/2009/07/quartz-composer-audio-spectrum-animata/] outlines calculations done to work out the frequency ranges for each band of the standard audio splitter.

Kineme Audio Input spits out a freq structure with much narrower freq bands (512 bands from memory). You could try summing the output from a section to get the 50hz resolution you are after.

scottbernoth's picture
Re: audio spectrum low frequency only

Does this help?

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Eg -Kineme Audio Waveform .qtz6.73 KB

rbetin's picture
Re: audio spectrum low frequency only

Hello all

I red with attention all your comments and collect some examples I finish to compile these into one composition attached bellow. I called it: Audio Spectrum VuMeter. I hope that can help.

Enjoy

Roger

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AudioSpectrumVumeter.qtz425.56 KB