Weighted measurements w/ Visual Analyzer

[Conrad Hoffman]

The current release of Visual Analyzer doesn't have the weighting implimented. I needed to do some A-weighted measurements and discovered that the program does have microphone compensation. All you need to do is create a text file with the frequencies and dB correction listed, then load it for each channel.

The attenuation for the various weighting schemes are widely available on the net, the only caveat is the numbers in the text file have to be inverted. If you want reduce the signal by 19.1 dB at 100 Hz, put 100 19.1 as a line in the text file, not 100 -19.1. Works like a charm for weighting, but could also be used for things like step baffle compensation or to apply noise filtration.

The file lives in the program directory under "compensation"- look at the standard ones in Notepad to see what yours should look like. Hopefully this will be useful to somebody. Someday. Maybe.

CH

[Jan Dupont]

Hi Conrad
Why not just post the .txt file

[Conrad Hoffman]

I'm normally pretty generous but since the files were created on client time, they're not really mine to post- that sort of generousity might not be appreciated, simple though the files are. I'd also feel bad about depriving people of the joy of creating a file and seeing it work for the first time. IMO, anybody interested in doing this in the first place will be sharp enough to figure it out. Lots of sites have frequency lists, but the truly intrepid can go to a site like http://www.diracdelta.co.uk/science/...ng/source.html
and get the equations with accurate coefficients and pop 'em in an Excel table.
Don't forget to flip the signs. Then, just copy the columns to a text file using Notepad and, as the saying goes, Bob's your uncle.

[Jan Dupont]

Thanks Conrad