Re: [sc-users] LowShelf/HighShelf

[James Harkins <jamshark70@xxxxxxxxx>]

Oh yeah.... I already did it in my library. Should have said earlier.

They do the coefficient calculation on the client side for speed. Not 
good for modulating the parms but good for "set and forget" eq.
hjh

On Sunday, May 2, 2004, at 19:34 US/Eastern, crucial felix wrote:

> see these :
>
> // Regalia-Mitra type filters
> // coded by jl anderson - 13 mar 2002
>
> eg:
>
> RMShelf {
>
> 	*ar {
> 		arg in,			// input signal
> 			freq = 440.0,	// the corner freq
> 			k = 1.0;		// RM k factor
>
> 		var allpass;
> 		
> 		allpass = Allpass1.ar(in, freq, k.sign);
>
> 		^( 0.5 * (in + allpass + (k.abs * (in - allpass))))
> 	}
> }
>
>
> I did try and do SOS coefficients a long time ago but I could never 
> figure out how to get from the 6 coefs in my texts to the 5 that we 
> use.
>
>
> On May 2, 2004, at 1:09 PM, newton armstrong wrote:
>
> > i've been making some synthdefs for equalisation. MidEQ is great, but 
> > it seems the LowShelf and HighShelf UGens are not finished yet. i 
> > figure both of these could be implemented using FOS but i'm not sure 
> > how to translate from a front-end like this: Synth("LowShelf", 
> > [\cfreq, cfreq, \db, db]) to FOS coefficients. has anybody done 
> > something like this already?
> >
> > _______________________________________________
> > sc-users mailing list
> > sc-users@xxxxxxxxxxxxxxx
> > http://www.create.ucsb.edu/mailman/listinfo/sc-users
> -felix
>
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____________________________________

H. James Harkins /// dewdrop_world
http://www.duke.edu/~jharkins

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This takes some practice."  -- Cyril Connolly