QSC Audio DSP-3 manual Introduction- Overview

Section 1: Introduction- Overview

The DSP-3 is a digital signal processor (or DSP ) accessory for audio power amplifiers designed to reduce the need for exter- nal signal processing while increasing overall system reliability through distributed intelligence. It is intended primarily 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-3 with Powerlight models requires remote mounting, external power supply and use of a special interconnect cable (PL6.0/9.0 only). Refer to the Appen- dix for application information. The DSP-3 can also be used with amplifiers that do not have a QSC DataPort (older QSC models, non-QSC models) with a reduced feature set and “remote” mounting/external power.

The signal processing capabilities include an Input Com- pressor-limiter, multiple Parametric Filters, High- and Low-Pass Filters, a Shelf Filter, Muting, Attenuation, Multiple Delays, Polarity Reversal, Audio Routing and Post Crossover Audio Mixing. Analog-to-digital and digital-to-analog converters are 24 bit resolution, 48 kHz. sampling rate. Additionally, the post- DSP output signals are daisy-chainable for connection to a second amplifier. Input sensitivity is selectable and dynamic range is greater than 93 dB. Inputs and the post-DSP outputs are electronically balanced. See Hardware Features for complete listing.

Physically, the DSP-3 is a small module that “piggybacks” onto the back panel of the specified QSC amplifiers. It connects directly to the DataPort on the back panel and is secured with supplied hardware. When used with other amplifiers, the DSP-

3 is mounted remotely on a rack-mount accessory that provides a solid physical mounting platform.

Connections include three D-sub type connections; a DB-9 connector acts as the RS-232 interface and an HD-15 through- connector provides the DataPort interface to the amplifier and other QSC DataPort products (if used). The “exposed” side has four terminal block connectors; 2 audio inputs and 2 post DSP outputs. There is also a power receptacle for using the DSP-3 with amplifiers that do not provide the required power through their DataPort, such as the ISA-series, older QSC amplifiers and non-QSC amplifiers. There are two LED’s; a blue one to indicate power status and a green one to indicate the presence of an input signal to the DSP-3.

Control of the DSP-3is accomplished with the supplied QSC Signal Manager software. Networked control using the QSControl platform is also possible (refer to QSControl docu- mentation for details). Please refer to the software documenta- tion (software Help file and Readme.txt file) for feature-set and operation information. This software provides an easy-to-use graphical user interface where DSP “objects” are placed onto a palette and interconnects are drawn. This interface allows for almost infinite configuration possibilities.

Connection of the DSP-3 to the host computer is made by connecting a serial cable between the DSP-3’s RS-232 port and the host PC’s available COM port. Once the DSP-3 has been setup as desired and the configuration saved to the DSP-3, connection to the PC is no longer required. This feature allows essentially tamper-proof amplifier DSP setup. Further changes can be implemented in the field by simply connecting a PC (i.e. laptop computer) and loading the new setup into the DSP-3.

Note: Powerlight 6.0 and Powerlight 9.0 amplifiers require that pin #9 be removed from the remote mounting interconnect cable. Amplifier damage may result from use of cable that has pin #9 connections present. Normal VGA computer monitor cables have pin #9 removed and are usable. Check before use!

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