Convolving

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vijay.garg@gmail.com
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Joined: Thu Oct 04, 2012 7:31 pm

Convolving

Post by vijay.garg@gmail.com »

Can we use Goldwave to convolve two audio files?
Gord
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Location: Canada

Re: Convolving ("Mixing") two files

Post by Gord »

vijay.garg@gmail.com wrote:Can we use Goldwave to convolve two audio files?
Yes. Take a look at the Edit > Mix... feature in GoldWave's help.
vijay.garg@gmail.com
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Joined: Thu Oct 04, 2012 7:31 pm

Re: Convolving

Post by vijay.garg@gmail.com »

Mixing is different thing. It is convolving.
GoldWave Inc.
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Re: Convolving

Post by GoldWave Inc. »

GoldWave doesn't have a convolution effect. The Expression Evaluator tool can be used to compute the product of two waveforms, but there is no simple way to computer the sums of the products. If one of the waveforms is very short, then you could plot the points in the Spectrum Filter effect, which convolves by multiplication in the frequency domain.

Chris
cdeamaze
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Joined: Thu Oct 05, 2006 3:19 pm

Re: Convolving

Post by cdeamaze »

Matlab or Mathematica will be the tools you can count on when everything else fails.
vijay.garg@gmail.com
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Re: Convolving

Post by vijay.garg@gmail.com »

A plug in can be used to convolve files in Goldwave. I can not put link but if you type " Convolver — a convolution plug-in " in google you will be directed to the site for downloading the plugins.
cdeamaze
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Re: Convolving

Post by cdeamaze »

VST (Virtual Studio Technology) is a popular format from Steinberg for loading plug-in effects into audio sequencers, hard disk recorders, sound editors, and trackers. ConvolverVST is a convolution plug-in for (version 2.4 of) that format.

It is known to work with the following programs:
console
Sonar 5
AudioMulch
n-Track Studio
Adobe Audition (which requires a stereo filter to be loaded)
Vijay, have you tried to see if it works with GoldWave?

You can also do convolution yourself with the help of convolution theorem.
1. Find spectrum for both signals using FFT.
2. Find product of spectrum - Multiply them pointwise in the frequency domain.
3. Take the inverse Fourier transform( IFFT).
jpnullnvoid
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Joined: Tue Apr 21, 2009 1:31 pm
Location: Philadelphia, PA USA

Re: Convolving

Post by jpnullnvoid »

Vijay,

You can kinda-sorta do a convolution effect in GW using the Noise Reduction tool. Here is the process:

1. Copy a short section of audio to the clipboard (idealy, less than 1 second in length).
2. Open another sound file to process and select the Noise Reduction tool.
3. In the Noise Reduction tool, select the clipboard as the source, max out your FFT size and overlap, reduce the amount setting to between 10 and 30, and check the box for outputting the noise source.
4. Process the sound.

The effect is basically the same as applying a filter which has the spectral characteristics of the sound you copied to the clipboard, but with the amplitude characteristics of the sound that you applied the effect to. The limitation to this method is that the filter is static. You would have to chop up your target sound in order to apply different filters to it and then paste them back together to get the "motion" effect that comes with standard convolution.

I hope this wasn't too confusing.

Have fun!
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