Virtual Systems 1447ferent physical architecture, Fig. 38-6A. MediaMatrix
was based on a PC that supports digital audio processing
cards inserted in it. What is now called Soundweb Origi-
nal consists of a family of digital audio processor boxes
that interconnect using category 5 UTP cables, hence the
web part of the name. Both products provide similar
functions in different ways.
Biamp, BSS Audio, Electro-Voice, Innovative Elec-
tronic Designs, Level Control Systems, Peavey, QSC
Audio Products, Symetrix, Yamaha, and others have
come up with a variety of products that also give the
user the ability to wire virtual devices together. These
range from large systems similar to MediaMatrix or
Soundweb, to a small module from QSC that provides
processing for a single power amplifier, Fig. 38-6A–E.
Many of these signal processors provide multiple
options for audio input and output. For example, Media-
Matrix provides options for analog I/O, AES3 I/O, and
a CobraNet interface.
In order for a virtual sound processor to replace all
the analog processing used in a sound system, a wide
variety of virtual devices must be available. MediaMa-
trix now provides nearly 700 standard audio processing
and control logic virtual devices on its menu. It is also
possible to build your own complex devices from
simpler devices appearing on the menu or existing
inside menu devices. Almost any audio processing
device desired may be either found on the menu or built
from components available.
Systems are designed in a manner very similar to
drawing a schematic on a CAD system. Virtual devices
are taken from the menu and placed on a work surface.
They have audio input nodes on the left, and audio
output nodes on the right side of the device. Some
systems have control input nodes on the top, and control
output nodes on the bottom of the devices. Wires are
drawn interconnecting the I/O nodes and the virtual
devices, Fig. 38-7.
Any number of virtual devices may be used until the
available DSP processing power is exhausted. All of the
systems provide some means for displaying the amount
of DSP used. Devices may be added to the schematic
until 100% utilization is reached. Expandable systems
such as MediaMatrix and Soundweb allow the addition
of more cards or boxes to add additional processing
power as needed. MediaMatrix also allows the selection
of sampling rate. Slower sampling rates trade off
reduced bandwidth for increased processing capability.
Since the schematic may be edited at any time, one
major advantage of these systems is that changes may
easily be made in the field to accommodate changed
requirements or field conditions. Since it is rare that a
system is 100% utilized, often the needed additional
virtual devices, or wiring changes, may just be added. If
the change exceeds the available DSP resources, often
some other change may be made in a less critical area to
reduce the required DSP resources. By contrast, in an
analog system physical rewiring or the purchase of
additional components would be required. Both of these
add significant cost. Thus often the use of virtual sound
processors results in significant savings in the total
project cost, over and above the cost savings of the
initial equipment purchase, and a more optimized
finished system.
Generally, double-clicking on a virtual device will
open it, allowing the internal controls to be seen, Fig.
38-8. Inside each device is a control panel with the
controls and indicators needed by that device. Some-
times seldom used controls will be placed in sub-
windows.
Selected controls from the devices may be copied
and placed in control panels. This is done using the
standard Windows copy and paste commands. The
schematic may then be hidden, and the user only
allowed access to the controls that the designer wishes,
placed on the control panels. Multiple controls may beFigure 38-5. Peavey MediaMatrix mainframe system, the
first virtual sound processor.
Peavy MediaMatrix Break Out Box (BoB).
Each BoB provides eight audio inputs and eight
audio outputs for a MediaMatrix processor.B.Peavey MediaMatrix Frame 980nt. The first
Virtual Sound Processor. It is a modular system
based on a Windows/Intel PC with added Digital
Processing Units (DPU’s). From one to eight DPU’s
may be inserted as needed based on the amount of
processing to be done.A.