fft analysis woes


    Jan 21 2007 | 10:58 pm
    Hello,
    I am working with audio analysis and am having some trouble getting the information I need.
    I want to analyse an audio signal and have an output similar to a spectroscope (not spectrogram!) where the amplitude of the various frequencies in a signal are displayed in a traditional x=frequency y=amplitude and can be used as control for various other processes.
    The spectroscope in max uses 30-40% of my cpu when there is a full frequency signal going into it and I cannot seem to access the individual frequency bands for use as control. I have read the analysis tutorials and I can't penetrate them. They seem to be all aimed towards processing.
    It says right at the beginning: "fft~ receives a signal in its inlet. For each slice of time it receives (512 samples long by default) it sends out a signal of the same length listing the amount of energy in each frequency region." Why can't I access this information? I feel like I am missing something fundamental. I don't even need 512 bands. 10 would be okay, 64 would be better, 128 would be good.
    I have a spectroscpe in my recording software only using 2% of my cpu so I know it is possible to do I just can't figure out how to do it in max.
    Cheers,
    Carey