IFB channels

[Chicago2210]

Good evening,
I have monitored the IFB channels for several of the TV stations in Chicago. I have noticed that the one for WMAQ TV is left on constantly and you can hear program audio minus the commercials. The ones for WLS and WBBM TV you can here program audio even commercials. Why is this? Also when monitoring WMAQ's yesterday, I noticed that when they tossed to sky 5 you didn't hear anything until they went back to the studio. Why is this? Thanks.

 

[ChrisP]

It all depends on how the station sets up the audio mixes to the IFB. In some cases the program audio is from a studio console, likely the audio console mixing the newscast audio. You may not hear the commercial audio as that comes thru master control in some stations. The IFB feed with commercial audio is probably coming from the main station program feed out of mater control.

The IFB feed that you did not hear the Sky 5 audio when they were talking was a "mix minus" IFB. It contained all the audio except the person who was in Sly 5. That is due to the latency of the link from Sky 5 thru the studio and back thru the IFB which causes a slight delay and is very confusing to someone who is talking and hearing themselves delayed, even for a few milliseconds.

Most HDTV feeds now days thru satellite or even microwave will have some delay or latency thru the digital processing and will require a mix minus IFB feed. If you ever see someone doing a live feed and suddenly pull their earpiece out, they are not getting the mix minus in to their ear...

- Chris