[sdiy] Anybody Know of FREE Frequency Plotting Software?

[cheater cheater]

Hi Ken,
the pulse method is very limited by the quality of your DAC and the
analog stage following it, the sweep gives much more solid results.

You will also find that the phase response is much more interesting
than the frequency response. Do some experiments with Voxengo Curve EQ
in clone mode to get the same frequency response as a piece of analog
gear, but with linear phase shift, instead of a "natural" phase shift
to see the difference.

Here are some terms that might help you in searching, I would have a
look around but I'm in the train and the internet here is only very
crappy:
- impulse response analysis
- frequency response analysis
- impulse deconvolution

I think the best bet is with acoustics engineering applications which
always have a special window for the FFT analysis of both sweep and
single-shot stimuli. This is used to reduce the effect of echo and
room reverb when building the room and when setting up the master
equalizer. Not sure if many of them will also have a frequency/phase
plot (rather than frequency/gain) but ones with features for filter or
crossover analysis certainly will.

Here seems to be a big linkorium, if you find the time to sift through
it you might find something: http://www.acoustics.org/software.html

Cheers,
D.

On Sun, Aug 1, 2010 at 04:09, Ken Elhardt <ken.elhardt at gmail.com> wrote:
>  JH  wrote:
>> http://www.sillanumsoft.org/
>>
>> I used to have this on my old computer, and I *think* it was free, or at
>> least very inexpensive.
>
> Thanks Jeurgen. If it does the function I described, then great. I
> downloaded it and it's free, but on my Win7 machine it said it
> couldn't detect an imput. I'll try to correct that or move it to
> another computer. It's a single .exe file and doesn't spray your drive
> and system folder with hundreds of folders and files nor modify the
> registry, just like in the old days when people used to know how to
> write software.
>
> And to Loscha who may have replied to me instead of the list by
> mistake. Yeah, I too have been using Cool Edit. I would run a sinewave
> sweep through a piece of gear for about 30 seconds, then it would
> display on the screen as a big rectangle in the waveform display
> outlining the freq plot. I would then open the FFT window and I could
> move the pointer on whatever peak or dip in the background wave
> display and read off the freq on the FFT window. But if I wanted a
> more accurate visual of the plot, I would have to run the .wav file
> through an app I wrote that would warp it into a linear dB scale. That
> was a pain. I later learned I could run a single tick sound (file with
> a single sample set to max) and that would cause me to record the
> impulse response of a piece of gear. Then by just opening the FFT
> display I would get a finished plot the way it should look. Something
> I just remembered after I started this thread, so that second way
> might be just as easy as using another piece of software specifically
> for the task.
>
> -Ken Elhardt
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