@database SFX

@Remark (C) Copyright 1993-1996 Stefan Kost
@Remark All Rights Reserved
@Remark $VER: Filter-FIRBand.guide (14.09.96)
@Remark AmigaGuide-OnLine-Help for SoundFX

@master /guides/sfx.guide
@index /guides/sfx-index.guide/index

@node main "Operators : Filter-FIRBand"

@{b}Filter-FIRBand ----------------------------------------------------------------
-------------------------------------------------------------------------------@{ub}

Function  :	Works on a specific frequency-band, means supresses or boosts it.
Parameters:	Effect		How much the operator effects the outcome.
				Negative effectvalues producing the opposite
				effect - they boost frequencys.
		Cut-Off1	lower bound, relative frequencies
				0.0 => 0 Hz
				1.0 => Samplingrate/2.0
		Cut-Off2	upper bound, relative frequencies
		Nr.		How many coefficients should be used. The more
				they are, the better results will be get.
				(max 64)
		Win		Windowfunction, to use for filtersynthesis.
ARexx     :	EffS/E		<Effektproportion> -100..100 %
		EModBuf,EModShape,EModMode
		CutOff1S/E	<Cut-Off1> 0.0 .. 1.0
		P1ModBuf,P1ModShape,P1ModMode
		CutOff2S/E	<Cut-Off2> 0.0 .. 1.0
		P2ModBuf,P2ModShape,P2ModMode
		Length		<Number of coeff.> 2..64
		Win		<wnr> 0..7
Notes     :	Please don't wonder because of these long calculation-times.
		If you are using e.g. 64 coefficients, SFX needs to do 128
		multiplications and 128 additions for each samplevalue. Since
		SFX lets you modulate filterspecifications (and not using fixed
		ones like other programs do), it has to redesign the filter
		each samplevalue. Therefore again a bunch of calculationsteps
		is neccessary. For @{" FIR-filters " link /guides/sfx-glossary.guide/Filter } a mathematical coprocessor
		really helps !
@endnode