Posted by: George Hall
In the beginning producers and on stage talent would communicate during live events using hand gestures, waving flags, jumping up and down…anything to get the attention of on stage talent or others behind the stage involved in the live event production. Sometimes it was important…like when the gas lights caught the stage fabric on fire at the back of the stage. Then along came technology, specifically the telephone and its many derivatives.
One application of telephone technology was to create an electronic means of getting someone’s attention during a live event without screaming, or any of the other previously necessary (and sometimes unseemly) means of getting that attention. This application of telephone technology for live event production is today known as an, “Interruptible Foldback” or IFB for short.
An IFB is, in our world a headset worn by production staff that allows controllable two way communications between camera operators, audio engineers and an event director who sometimes are hundreds of feet apart and in many cases not even in the same room as the event. By controllable we mean that the event director can enable or disable two way communications if he or she so chooses to cut down the “chatter” that our crews seem to engage in during a live event. I I have found that that chatter has nothing to do with the event itself. Think of an open IFB as a party line. Everyone can talk to everyone else at the same time if they want. Of course that is perilous at times which is why you give the producer the ability to cut off the chatter. The biggest distinctions between IFB systems are the number of people that can participate in the party line and even more importantly sound isolation. We produce a broad variety of live events. Most are very quiet with mostly spoken words and video clips with audio that produce peak decibels of 40-60db. Other events we produce however are full blown rock concerts where the peak decibels can exceed 100db. In order to communicate with all of your audio and video technicians during a live event that is that loud you need two things. Both ears of each technician wearing an IFB headset must be covered with extreme sound isolation headsets.
You want to be able to hear the mix minus audio and directors instructions through your IFB, not from ambient in-room sound bleeding through the headsets. The second thing is that in these types of extreme sound environments you cannot have two way communications over the IFB because of the tendency of the microphone that is part of the IFB headset to transmit the ambient sound from each of the technician’s positions. In cases like this where two way communications are required but not possible using the IFB we suggest going back to jumping up and down and waving furiously.
About the Author:
George Hall Founder/President of VideoSSC. He has over 30 years’ experience as a high technology engineering executive. With significant experience in high performance computing, Military electronics, IP networks and Video Broadcasting. Board member Public Television. An author and frequent guest on technology programs and panels. He holds a BA in mathematics from Hillsdale College.