FRONT OF HOUSE
BEYOND WHACK-A-MOLE | Kent Morris
Networked digital audio is now the norm for most churches . Whether it ’ s a simple X32 and stage box or a complex Rivage system with seven RIOs , audio depends on a network protocol for data transfer . While it may appear live production is now just a subset of IT , the truth is we use IT devices as the best means to an end . Even so , it helps to understand how to use the services of IT within a live audio environment .
The basis for digital audio initially focused on conversion of analog signals into a temporary digital state in order to manipulate the signal in ways outside the analog domain , such as extended EQ , direct application of effects and routing which would have been impossible with physical cable patching . A second goal was to reduce the physical dimensions largescale analog audio had become with eightfoot consoles , dual outboard power supplies , huge processing racks and a myriad of loomed interconnects and isolation transformers .
As a result , first generation digital desks were drop-in replacements for their analog counterparts and failed to integrate true network capability . However , as the control surface became removed from the processing , the need for networking became clear . Initially , each brand used its own protocol , but Dante and AVB have become the standards in most venues with Reidel found in higher-end situations . Today , an audio network is used to connect and send signals among several local consoles , for FOH and MON as well as remotely located ones in the broadcast area and even “ tapped off ” pairs for outdoor runs and overflow rooms .
Audio over Ethernet networks must deliver each packet of information in a time consistent basis . Audio cannot be pieced back together as other data samples can be . Audio must also have a low enough latency period as to remain inaudible , typically < 5mS throughput . As a result , audio needs its own protocol in order to remain a viable product . Dante is a product of Audinate out of Australia and has succeeded due to the fact Audinate doesn ’ t build audio hardware , so they are a neutral site . Dante is relatively easy to learn and Audinate offers free training at www . audinate . com on three levels . AVB ( Audio Video Bridging ) was set to take over the industry thanks to its heavy-weight backers such as Cisco , Intel and Harman , but its adoption has been slower than expected as the industry adopted Dante more easily . AVB does have distinct advantages over Dante in error correction , latency and scalability , but is
only seen in Meyer , PreSonus and a few other manufacturers ’ products .
In use , audio networks exhibit the same pluses and minuses of regular IT networks : great when they work and show stoppers when they don ’ t . One simple way to improve uptime is to use high quality cabling , routers and Wireless Access Points ( WAP ). A Wal-Mart router is a sure way to create audio issues and poor quality CAT cables always create havoc . In addition , keeping IT off the audio network will improve its performance to a large extent . Keep IT hardware away from the Dante system and things will improve . Lay out the audio network for easy serviceability and don ’ t put anything except secure information on it . Use passwords and even encrypted data when going wireless for remote console control and personal monitor mixing .
Most operational issues come down to an incorrect setting , so be sure to document the proper set-up on a laminated sheet glued to the network rack . By treating the Dante or AVB system as the critical interconnect it is , you can prevent network errors and a ruined event .
Kent Morris Kent is a 40-year veteran of the AVL arena driven by passion for excellence tempered by the knowledge digital is a temporary state .