Routing audio signals for sound systems has typically been performed using separate analog lines. Digital routing is increasingly being considered as an alternative, however. I recently evaluated QSC’s, RAVE system. Routing Audio Via Ethernet (RAVE) enables one to route multiple channels of audio via standard Fast Ethernet hardware and cabling.
Product PointsApplications: Live sound; installation
Key Features: Analog or digital models; up to 64 channels with various I/O configurations; Ethernet-based; digital networks
Price: >RAVE 160s: $2,850; 161s: $3,600; 188s: $3,250; 80s: $2,700; 81s: $3,300; 88s: $3,100
Contact: QSC at 714-754-6175
RAVE provides a means of transporting up to 64 channels of 20-bit/48kHz audio over a 100BaseT network. A minimum of two RAVE devices are required, one to send and one to receive. There is no set limit to the number of receivers a RAVE network will support. At any configuration, latency is fixed at 6.3 ms.
(QSC recently added capabilities to the RAVE System. New RAVE “s” models can now operate on switched networks, which allows users to route audio and computer data on the same Ethernet network without affecting the audio signal. Ethernet switches allow RAVE to link to various high-capacity networks, such as Gigabit Ethernet, enabling users to route hundreds of audio channels-Ed.)
There are six RAVE models available, three analog models and three digital. The connections on the analog models are all balanced line level I/Os configured with 16 ins, 16 outs or eight in/outs. The digital models share the three configurations but the I/Os are AES/EBU.
Each RAVE unit is a standard rack-mountable device 19″ wide, 1.75″ high and 13.2″ deep. The front panel has 16 tricolor LEDs, each corresponding to an audio channel to indicate its relative signal presence and level. Also on the front are eight status-indicator LEDs to display the operating condition of the RAVE unit and its Ethernet network.
The LEDs are color-coded: green means normal, red a problem and yellow is informative. A screw panel door completes the front with four hexadecimal rotary switches for setting addresses. (The RAVE system handles routing in groups of eight individual audio channels as a network address. ed.) There is an AC power LED and all RAVE units operate within a 90 to 264 VAC at 47 to 63 Hz, making it useable anywhere.
The rear panels offer a variety of connections based on model configuration. The three RAVE (analog) models 160, 161 and 188 offer “Euro-style” detachable headers, for wire termination. Digital models 80, 81, and 88 offer 3-pin XLR AES3 inputs and/or outputs. The rear panels of all models offer sync connections (BNC-type connections between units), a RS-232 serial port for control, and an AC power connector.
I used the RAVE system provided by Altel Systems of Brewster, N.Y., during a run of shows last year while touring with Tony Bennett. It was used as a drive snake for FOH PA and monitors. The units I used were the RAVE 160 and 161, which were wired with an XLR harness from each unit by the QSC factory. Although the input sensitivity and output level can be adjusted to optimize gain structure, I used the factory default setting at +12 dBu, which perfectly matched my requirements. I located one unit at the stage next to the amplifiers and positioned the other unit at FOH, where all outputs from the console to drive the PA and monitors were terminated to the RAVE unit.
I ran a single 300′ CAT-5 cable – with a diameter no bigger than a microphone cable – terminated the RJ-45 connectors to the units up-and-running. The impressive thing was that this replaced two drive snakes consisting of 16 separate audio lines.
The application of routing audio can be very simple from point A to B or can be very complex when designing routing for airports, studios, convention centers or large-scale resorts or theme parks. RAVE offers a solution to all these requirements in a reliable signal transport system that will dramatically reduce costs, increase routing possibilities and ultimately improve audio performance.
In a variety of venues, from theatres to sheds, the units worked flawlessly and were extremely reliable for the two months I used them. With its ability to minimize susceptibility to RF and EMI from the AC line, the RAVE system is a welcomed alternative to traditional copper snake systems. Because this system is Ethernet-based, it easily supports system reconfiguration and expansion not available with traditional systems. The QSC RAVE system is well worth the consideration of system designers, live sound companies and contractors searching for a flexible, reliable router for any audio application.