"Gary Eickmeier" writes:
[...]
The most basic and foolish mislead is thinking that good "stereo" comes from
the direct sound alone, and trying to kill the room reflections or design a
speaker that casts all of its sound toward your hapless ears. This
misconception, or mislead, is caused by the confusion between stereo and
binaural.
There are serious problems in accurately recreating a sound field using
stereo in the manner you're describing. The most basic linear systems
theory and acoustics will tell us this logically.
In all cases the sound reaching the listener can be described in the
frequency domain as
L(\omega)= F(\omega) . H(\omega),
where F(\omega) is the signal, H(\omega) is the room response, and "."
represents multiplication. In the time domain this is
l(t) = f(t) * h(t),
where "*" denotes convolution and h(t) is the impulse response of the
room.[1]
Consider the case of a "dead" signal source, e.g., a single human
speaker in a small room, and a "live" room in which the impulse response
h(t) is significantly longer than that of the recording environment.
Then you will necessarily perceive the "wrong" sound field.
Was Dr. Duane Cooper, formerly of the University of Illinois/Urbana a
fool? I think not! He formulated a concept of "transaural processing"
which accounted for the room response, interaural crosstalk, and head
related transfer functions so that the original auditory event could be
faithfully recreated at the listener.
The problem with Cooper's method is that, with the technology at that
time, the listener was locked into one position - not very practical.
Also the formulated problem would only work for one listener.
However, there may be feasible solutions at this day and age involving
multiple emitters, tracking technology, and adaptive beamforming. All
TBD...
--
Randy Yates
Digital Signal Labs
http://www.digitalsignallabs.com