QSC DSP-4, Hardware Manual

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3
Introduction
The DSP-4 is a digital signal processor ( DSP ) accessory for
audio power amplifiers. It is designed to reduce the need for
external signal processing while increasing overall system
reliability through distributed intelligence. It is intended pri-
marily for QSC’s CX, DCA, and Powerlight2 series amplifiers
and mounts directly to the rear panel of the 2-RU, 2-channel
models of these amplifiers (pre-August, 1999 date-code of
the CX, DCA and Powerlight2, and all ISA models will
require use of an external power supply). Use of the DSP-4
with Powerlight models requires remote mounting, external
power supply and use of a special interconnect cable
(PL6.0/9.0 only). Refer to the
Appendix for application infor-
mation. The DSP-4 can also be used with amplifiers that do
not have a QSC DataPort (older QSC models, non-QSC mod-
els) with a reduced feature set and remote mounting/exter-
nal power.
The signal processing capabilities include Compres-
sors, Limiters, multiple Parametric Filters, High- and Low-
Pass Filters, Shelf Filters, Muting, Attenuation, Multiple
Delays, Polarity Reversal, and Audio Routing. A new feature
of the DSP-4 is amplifier output Power Limiting (QSC
DataPort amplifiers only). Analog-to-digital and digital-to-
analog converters are 24-bit resolution and 48 kHz. sam-
pling rate. Post-processor audio outputs are daisy-chain-
able for connection to additional amplifiers. Input sensitivity
and output level is software selectable. Dynamic range is
greater than 106 dB. Inputs are balanced and the post-DSP
outputs are pseudo balanced.
Physically , the DSP-4 is a small module that “piggybacks”
onto the back panel of the specified QSC amplifiers. It con-
nects directly to the DataPort on the back panel and is
secured with supplied hardware. When used with other
amplifiers, the DSP-4 is mounted remotely on a rack-mount
accessory bracket providing a solid mounting platform.
There are two LED’s; blue to indicate power status and
green to indicate input signal presence.
Connections include an RS-232 port and a DataPort pass-
through connector for use with QSC DataPort products . For
non-DataPort applications, two XLR audio inputs and two
XLR outputs (post-DSP) are provided. There is a power
receptacle for use with amplifiers that do not provide
DataPort power or with non-QSC amplifiers.
Control of the DSP-4 is accomplished with the supplied
QSC Signal Manager software and an RS-232 connection
between the module and PC. The Signal Manager software
provides an easy-to-use graphical user interface where DSP
“objects” are placed onto a palette and connected. This
interface allows for almost infinite configuration possibili-
ties. Once the DSP-4 has been set up as desired and the
configuration saved to the DSP-4, connection to the PC is
no longer required. This feature allows essentially tamper-
proof amplifier DSP set up. Further changes can be imple-
mented in the field by simply connecting a PC and loading
the new setup into the DSP-4.
Operation over an Ethernet network can be accomplished
using QSC’s QSControl platform. Please refer to the soft-
ware documentation (software Help file and Readme.txt
file) for supported feature-set and operation information.
From all of us at QSC Audio, thank you for your purchase. Be
sure to check our website at
http://www.qscaudio.com
for the latest software and firmware updates as well as
sample DSP configurations.