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I'm looking for an affordable software package that does FFTs and will interface directly to a sound card or .wav file. I've looked at several: Wavpad is reasonable cost but their FFT function leaves a lot to be desired, FFTW is shareware but I don't want to have to write the frontend for it, and SpectraPlus is really nice but is too expensive. Right now I'm considering Strobosoft 2.0 Deluxe for $100, a bit more than I want to pay but it does provide other useful functions.

Any comments on FFT programs in general and Strobosoft in particular?

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Steve Smith
"Music is what feelings sound like"

Steve,

is your application audio production or sensor interface?

There are a number of basic audio packages out there that do FFT, as well as waterfall plots and phase diagrams...

A quick source for some basic software packages that we use when working with hydrophones are WaveLab, and Virtins..

The quality between the programs offered really varies based on bin size...

Stephen

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www.ziegenfussguitars.com

By far, this is the best available. We use it all the time. It's free, and works on linux and windows.

Of course, this is code based. If you are looking for a GUI based application (based on FFTW) try this:

http://www.employees.org/~stannous/gstring.html

Mike

Try Visual Analyser at http://www.sillanumsoft.org/ so far seems good and is free

Fred

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Fred Tellier
http://www.fetellierguitars.com
Facebook page http://www.facebook.com/pages/FE-Tellier-Guitars/163451547003866

Steve, I have used Wavesurfer for a few years now with good results.

http://www.speech.kth.se/wavesurfer/

Once you have recorded your "bonk" of the piece to be tested, use only the first 100 milliseconds of the response and then use the FFT option. Capture a significant quantity of data points. Then you can import the file to Excel for manipulation and delete all of the recorded points above 1000 hz. and produce your graph as an X-Y scatter plot with dba on the Y scale and frequency on the X scale.

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Peter

'Wavesurfer' can be downloaded free from:
http://www.speech.kth.se/software/
nice GUI interface, has it's own recording setup, and gives lots of options, including spectrogram, but not waterfall plots.

I got 'Cool Wave' back when it was shareware, and use that for recording and manipulating sounds in general. The frequency analysis module for that works well enough, but it's hard to isolate a peak, for example.

When I just want an FFT, I use FFT4WAV3, DOS freeware. It's tiny, and fast: it was written when the 386 was new and hot. It's also a one-trick pony, and a bit quirky. I like it, in part, becuase it can save any file it can open as a comma delimited text file that can be opened by any spreadsheet. I used that, for example, when I needed to sum over the force differential output I was getting from my piezo pickups to see the actual wave form of the force function.

FFT4WAV3 gives the output either as 'real' and 'imaginary' parts, or as amplitude on a linear scale, and you can zoom in as close as you want to look at a peak. You could use this, for example, to find Q by bandwidth from a tap tone, although, as usual, there are some limitations.

The major drawback is probably that the 'record' function in the software was written to interface with an older soundcard standard: it doesn't get anything from the cards I have.

Great options. A quick glance through the sites shows any of these should work fine. And most of these are free! I'll be downloading and playing with these this weekend.

Thanks all !

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Steve Smith
"Music is what feelings sound like"

One more: Audacity. It's not nearly as flexible as Wavesurfer (which I also like) but if you're mainly looking for the peak frequencies, I find Audacity is less quirky and easier to use.

My main problem with Wavesurfer is that I can't get it to do the FFT on the selected signal. That is, if I click and drag to create a dotted yellow selection, the Spectrum Section plot doesn't account for the full selected region, even if I click the "Average of selection" box. It only analyzes from where my selection starts (the vertical yellow line on left) to the ~0.5 seconds afterwards to get enough data for the 8192 FFT points (what I use, with 16k samples/sec).

A quick-start on Audacity:
- Install as usual. http://audacity.sourceforge.net
- In Audacity: Edit > Preferences > Audio I/O > Select your recording device > OK.
- Record the taps.
- Select the tap(s) signal with the mouse
- Analyze > Plot Spectrum
-- Change 512 to 16384
-- Change Linear Frequency to Log Frequency
-- Drag the right window edge to make it a *lot* wider
-- Hover the cursor near the peaks... Audacity will automatically lock onto the peak frequencies! Numbers are in the lower left. I've found it's within 1 Hz of Wavesurfer for the air, top, and back modes.

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David Malicky

Thanks David, I'll try that one too.

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Steve Smith
"Music is what feelings sound like"

Audacity can to spectral analysis??

Mike

Yeah, the program appears to have come a long way in the past few years. Amazing what a community can do.

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David Malicky

Cool! One of my favorite uses is to slow music down while maintaining pitch so I can learn them 180 beat songs by Stephen Bennett!

Mike

If it'll do that then I'm downloading it for sure. I've been trying to figure out this acoustic jazz riff for a month and just can't quite get it cause its just too fast.

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Steve Smith
"Music is what feelings sound like"

Mac user here - I dropped the cash for Electroacoustics Toolbox, love it.

For slowing down music - Amazing Slow Downer.

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The member formerly known as erikbojerik....

Steve,

It will most def do that. And its quite easy. PM me with any questions once you have it installed. After I slow them down, I transfer them to one of my iPods, put on the headphones, and play along. For the money, Audacity is an incredible deal.

Mike

Thanks Mike, hard to beat free

I just downloaded it and some of the plugins that looked useful. I'll play with it tonight.

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Steve Smith
"Music is what feelings sound like"