In Eq.(3.2) we defined the allpass notation
by
A look at allpass.h reveals that Freeverb implements
As a result, each of the four Freeverb ``allpass'' sections is really a feedback comb-filter
A true allpass is obtained only for
(reciprocal of the ``golden ratio''). The default value used in
Freeverb (see revmodel.cpp) is
. A detailed discussion
of feedforward and feedback comb filters appears
in §2.6, and corresponding Schroeder allpass filters are
described in §2.8.