"We need to deal with up to 14 incoming sources at any one time so we use the iDR-8 with expansion units to give a 16x16 clean-feed matrix," explains BBC Radio Outside Broadcast Manager, Jonathan Wilson.Generally, commentary circuits are fed into the local control room on digital bearers, which could be Vandas or ISDN. These are subject to a noticeable transmission delay, which means that the return path of the 4-wire - back to the commentator's headphones - must be fed with a 'clean feed' or 'mix-minus' signal, so that the commentator doesn't get put off by hearing him/herself delayed.
Wilson continues: "We can control the gain of each source and compress/limit each outgoing to smooth the feed to the commentator and ensure that wild studio levels don't upset the outgoing digital bearers. In a three or four studio set up - such as the one we had at the last Olympics - I can keep a single laptop across all the iDR devices on the network, monitoring studio cues in the control room and adjusting as necessary.
(Lee Baldock)
