BSS SW9088II Audio Processor
The 9088iis Networked Signal Processor forms the heart of the Soundweb system. In a single rack space unit, it offers 8 analogue audio inputs, 8 analogue audio outputs, 200 MIPS of digital signal processing, a pair of network jacks, and a variety of control options.
The front panel of the 9088iis has a number of LEDs to allow a quick view of activity on the audio inputs and on the network. It also has a mini-DIN connector for an RS-232 serial port: this is normally used to connect a PC for system setup and control.
The rear panel contains the audio inputs and outputs and the network jacks. It also contains a second RS-232 port, which is normally used for control from an external controller such as AMX or Crestron. Finally, it contains a control connector: see section 4 Control options for a description of how this is used. Both control i/o and analogue i/o connections are made via "Phoenix" style two-part screw terminals; the female connectors are shipped with the Soundweb unit, so installation can be made with no soldering and no extra connectors to buy.
The 9088iis contains two preamplifier cards for the analogue inputs: each card handles four of, the inputs. Three types of card are available: the analogue line card, the analogue mic/line card and an AES/EBU Digital Input/Output card.
The line card gives a choice of two gain settings: 0 dB and 12 dB (intended as a pro/consumer switch). The mic/line card provides a range of gain settings from 0 dB to 72 dB, together with phantom power and phase reverse. In all cases, each input can be switched individually.
The Digital input card holds two AES/EBU stereo inputs and outputs, with input sample rates from 32kHz to 96Khz. Output sample rates are user-selectable from 44.1kHz, 48kHz, 88.2kHz and 96kHz, and an external word-clock sync input is provided for house-reference.
The 9088iis device can be configured with digital and analogue mic or line input cards to specification.
The analogue outputs are equipped with analogue attenuation after the DAC stage. If the unit is used at anything lower than its full output level, it makes sense to apply the final gain reduction in the analogue domain: in this way, the DAC noise is also attenuated and the signal to noise ratio is kept at a maximum.
The core of the 9088iis contains two Motorola 56303 DSP chips, running at 100MHz each and thus providing a total of 200 MIPS of DSP. There is also a block of dynamic RAM allowing a total of 11 seconds of audio delay. The main control processor is a Motorola 68000-series CPU, which runs a real-time multi-tasking operating system; this CPU takes care of system operation and interfacing and performs all the necessary housekeeping functions. Finally, the core contains a flash EPROM (see section 5 Flash EPROM storage), in which is stored all of the software to run the unit, and also the unit's configuration.