Most of the pieces in this concert are in multichannel format, and
therefore sound should be spread around the audience from at least
eight different sound sources or loudspeakers. The recorded material
should be played on a multichannel recorder routed in a discrete
fashion to a multichannel console with also at least eight different
channels. No mixing or diffusion is required for most pieces. In order
to perceive the dynamic and motion of sounds two configurations or
options for speakers placement are suggested:
Following is figure 1 which illustrates the idea of the truncated pyramid sound space.
Please note that there are eight speakers, a bottom plane and a top
plane. The listener is in between those two planes but also surrounded
by walls or boundaries which in turn can also form four corners to
obtain different sound object trajectories. In order to get the
truncated pyramid shape panning or panoramic and if the concert room
is symmetric, controls for the upper plane speakers should have a
slightly lesser angle value than the bottom ones. In this way an
illusion of tri dimensional motion might be perceived in the room. Of
course since each individuals head related transfer function is
different the effect cannot be guaranteed. Nevertheless this
configuration has been proved optimal for compositions with eight
channels. The sound moves side-wise in a 270 degrees pattern while at the
same time can also be perceived with a height of plus or minus 90
Figure 2 is a layout for a group of also eight speakers viewed from the top of the concert room or auditorium. This configuration is optimized for sound diffusion where motion in a two dimensional plane is much desired.
The goal on this configuration is to obtain a 360 degree panoramic perception of a sound in motion. It is very effective but in order to preserve the reverberation nature of a composition some delay needs to be added to the speakers closer to the audience. In this figure the group of 3,4,5,6 needs some delay to compensate the distance of the other speakers. An important feature in this layout is the use of virtual semi circles or also circumferences of different radius given that we have a sound source of 360 degrees. This sort of effect is achieved by adjusting sound intensity of the different and desired groups of speakers. Panning in the mixing console should have the maximum angle amplitude for the group toward the left or toward the right.
© Copyright 2003 CCRMA, Stanford University. All rights reserved.
Created and Mantained by Juan Reyes