Next 
Prev 
Up 
Top

Index 
JOS Index 
JOS Pubs 
JOS Home 
Search
Length
FIR Loop Filter Controlled by ``Brightness'' and ``Sustain''
Another convenient parametrization of the secondorder symmetric FIR
case is when the dc normalization is relaxed so that two degrees of
freedom are retained. It is then convenient to control them
as brightness
and sustain
according to the
formulas
where
is the period in seconds (total loop delay),
is the
desired sustain time in seconds, and
is the brightness parameter
in the interval
. The sustain parameter
is defined here as
the time to decay by
dB (or
timeconstants) when
brightness
is maximum (
) in which case the loop gain is
at all frequencies, or
. As the brightness is
lowered, the dc gain remains fixed at
while higher frequencies
decay faster. At the minimum brightness, the gain at half the
sampling rate reaches zero, and the loopfilter amplituderesponse
assumes the form
A Faust function implementing this FIR filter as the damping filter in
the Extended Karplus Strong (EKS) algorithm is described
in [456].
Next 
Prev 
Up 
Top

Index 
JOS Index 
JOS Pubs 
JOS Home 
Search
[How to cite this work] [Order a printed hardcopy] [Comment on this page via email]