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Golay Code Measurement Procedure

  1. Generate the Golay codes golayA.wav and golayB.wav using generate_golay.m.
  2. Open the pd patch golay.pd, in pd.
  3. Ensure that the patch is not in editing mode, and check the ``compute audio'' box in the main pd window.
  4. Adjust the ``Output Volume'' so that when you click on ``Record Response to Golay A'', the system under test is behaving linearly (i.e. not clipping), but so that the input signal to the sound interface is not too noisy.
  5. If there is an input volume on the sound interface, adjust it so that the levels approximately match those shown in Figure 6 when you click on ``Record Response to Golay A'' and ``Record Response to Golay B.'' If the sound interface has no input volume, then you will need to adjust the ``Output Volume'' accordingly.

    Figure 6: golay.pd after making a measurement with an appropriate input level
    \resizebox{4in}{!}{\includegraphics{\figdir /golayScale.eps}}

  6. Once you are satisfied with the results, click the ``Write Responses to Disk'' button.
  7. pd will write the files RespA.wav and RespB.wav to disk. Rename these files so that the names match the measurement you just made. For instance, you might rename them to hpfRespA.wav and hpfRespB.wav if they corresponded to the measurement of a high-pass filter.
  8. Run golay_response('hpf') in MATLAB or Octave to analyze the measured response. Plots will be created, and the file hpfImpResp.wav will be written to disk.

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Download imp_meas.pdf

``Transfer Function Measurement Toolbox'', by Edgar J. Berdahl and Julius O. Smith III,
REALSIMPLE Project — work supported by the Wallenberg Global Learning Network .
Released 2008-06-05 under the Creative Commons License (Attribution 2.5), by Edgar J. Berdahl and Julius O. Smith III
Center for Computer Research in Music and Acoustics (CCRMA),   Stanford University