(1/12th etc..) Octave Smoothing Algorithm

[digidocs]

I've been doing some MLS measurements with some homebrew software lately. I can calculate frequency responses pretty well but I'd like to be able to do 1/8th, 1/12th, etc. octave smoothing to make my results directly comparable to other packages. Does anyone have any references for these smoothing aglorithms? I'd like to know what the actual math is...

Thanks,
David Carr

 

[annex666]

I imagine it would involve calculating the midpoint of the 1/8th or 1/12th octave band, then averaging the response across the region +/-1/16th or +/- 1/24th regions around those midpoints.

The 1/12th, etc measurements you see from commercial software are often in the form of a bar chart/histogram - this would suggest that
what I say above is true.

There could be more complex ways of doing the same thing - i.e. calculation of a Gaussian curve that has 1/12th octave bandwidth at each 1/12th octave middle point - then use this to weight the average.

There are many ways to do it, but without seeing the source I can't tell you how a specific commercial software package does this.

Hope this helps.

..also I'm about to start work on my own measurement system for LTI systems (based on MLS techniques), so you might see a post from me on the forum with some screenshots (when I finally get round to it!)