macOS Equalizer

[Resister]

Hello,

Does anyone know and/or have an example of how to build and equalizer like that in iTunes ? I don't mean a graphical one, I want to make one like this:
http://hints.macworld.com/images/eq_big.jpg

Appreciate the help.

Thanks.

 

[robvas]

It's just a bunch of Slider controls. The audio 'brains' behind what an EQ actually does are probably complicated.

http://en.wikipedia.org/wiki/Equalization_(audio)

 

[Resister]

Yeah, I'm just wanting to know if anyone has any code for the "brains" of it.

I've read that Apple's AudioUnits would need to be used, but thats a bit above me.

 

[gnasher729]

Yeah, I'm just wanting to know if anyone has any code for the "brains" of it.

I've read that Apple's AudioUnits would need to be used, but thats a bit above me.

A digital equaliser requires some rather complex maths, FFTs, manipulating the frequencies, transforming back, doing everything very carefully to avoid audible glitches, so I think going through the documentation for audio units is your best chance.

BTW. If you find something in there that allows changing playback speed without changing pitch I would be interested in hearing about that, just out of curiosity.

 

[cMacSW]

You may want to look at CoreAudio

 

[ghellquist]

Free software

You might want to search for free open software doing audio editing. Reading the source code might help in understanding how the algorithms work. You might also have a starting point for experiments.

The projects coming to my mind are
Audacity -- I believe it only runs equalizer in "batch" mode
Ardour -- source code available

//gunnar

 

[firewood]

BTW. If you find something in there that allows changing playback speed without changing pitch I would be interested in hearing about that, just out of curiosity.

Core Audio on Mac OS X includes the AUTimePitch Audio Unit.

On iOS, Dirac reportedly sells a commercial time pitch library.

 

[chown33]

BTW. If you find something in there that allows changing playback speed without changing pitch I would be interested in hearing about that, just out of curiosity.

Audacity > Effect > Change Tempo