Re: [Audacity-devel] Graphic Equalizer

[<Mar...@ao...>]

Richard
 
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I presume this would be in addition to the "move the points on  the
graph" interface, not replacing it?
I quite like the graph approach,  partly because I've never got on with
hardware graphic equalisers or sliders  you move with the mouse.
I know a lot of people (think) it would be a lot  better though.
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I figured it as an alternative interface - I quite like the 'move the  
points' approach.
 
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Are the fixes to the processing code in CVS HEAD? when I can get it  to
compile I'll give it a try.
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They are not but you just need the 4 files in the zip at 
_http://members.aol.com/MartynShaw/eq1.zip_ (http://members.aol.com/MartynShaw/eq1.zip) 
Replace the files you have in src and src/effects and recompile.

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> It would be great if you had a choice control at the top  letting users 
> choose between 5, 9, 17, and 31-bands (or whatever  choices make sense).
There are some standard numbers of bands and center  frequencies for them
laid down. Not quite sure what they are, but I know you  get 15 and 31
bands to cover the range 20Hz to 20kHz, which is 3  decades.
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I'm on to this - there is an ANSI standard.

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> > 3 What is the 'best' shape for the filter curves?
>  
> You could make a nice smooth curve using cubic interpolation - the code  
> to do cubic interpolation is already in FreqWindow.cpp.
If we can do  this, we are promptly ahead of most hardware EQs, which
have a bunch of  bandpass filters and a mixer circuit, giving some very
odd results if you set  all the sliders to the same about of boost for
example. I can't think why it  would be desirable though, so I would go
with the interpolated curve - at  least it's obvious what's going on with
the graph display, unlike a hardware  EQ.
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I will try out a few options - the result being flat if you increase /  
decrease all the faders the same amount sounds like a worthy aim.
 
Martyn