Re: Spectrum analysis in JAMin is incorrect.

The frequency scale isn't linear, it looks like it's at least roughly
logarithmic, in which case it's quite possible that *is* what white
noise looks like.

Best
Dan

2011/3/29 David Nielson <[email protected]>:
> After changing the update frequency for the FFT analysis in JAMin, I
> thought I'd see if I could fix another long-standing complaint of mine:
> the graph never even gets close to the top of the window, so while there
> might be really interesting things going on at low volume levels, I
> can't see them.
>
> It seems like the signal is getting some automatic gain control
> (compression) before the FFT stage, separate from the compression that
> JAMin is doing itself, to keep the visual of the signal visible. Passing
> several test tones through to see what they looked like, I discovered
> this in the 30-band spectrum page:
>
> http://www.naptastic.com/david/jamin-graph-wrong.png
>
> The input being analyzed is white noise. It displays correctly on the
> HDEQ page, but here, well, that ain't what white noise looks like. (You
> can ignore the peak indicators being in weird places; that's from the
> other test tones I ran.)
>
> So, I'm gonna jump back in the code right now, but I thought y'all might
> want to be aware, there are some gremlins in there that it seems no one
> has noticed before.
>
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