Brett,

Brett Nordgren wrote:
> Larry,
> 
> When I do an FFT on a PSN file, the result is normalized to fill the screen 
> vertically.  Is there any way to extract the normalization factor so that I 
> could use the results to generate a calibrated noise spectrum?

Not within WinQuake. With the current version of WQ you can export the raw FFT data 
so you can analyze the FFT data using other programs like MATLAB or Excel. To do this 
create an FFT Window and use the File / Export menu items. The resulting file will 
look like this:

Freq,Real,Imaginary,Magnitude
0.000190735,-0.0925326,0.182551,0.409328
0.00038147,-0.17057,-0.0860256,0.38207
0.000572205,0.110639,-0.0927722,0.288774
0.000762939,-0.0952175,0.178415,0.404466
0.000953674,-0.15761,-0.0518402,0.331834
0.00114441,0.0554941,-0.136885,0.295412
0.00133514,0.02051,0.0920337,0.188583
....

The first number is the frequency then the real and imaginary numbers from the FFT 
function and then the magnitude. The magnitude is calculated using the following C code

mag = hypot(Real[i] , Imag[i] );

Regards,
Larry Cochrane
Webtronics


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