How are networks broadcasting now?

[hef]

Are they sending out separate feeds? Like for analog are they broadcasting both an LoRo and an Lt Rt thru the analog signal? Or is it one or the other?

And for digital, dolby digital 5.1 (AC3)? and also a separate stereo? Or is the stereo just a folddown from the 5.1 using its metadata?

I'm sure different networks do it differently but just wondering what the majority are doing.

[Postman]

The only one I know about is PBS. The stereo mix you create will go out everywhere (YOU decide if it is LoRo or LtRt, both are accepted), and it is to be limited at -10dbfs with a fairly typical dialnorm range. The 5.1 mix you make will go with any hi def feeds. That has the same dialnorm and dialog dynamic range restrictions but the overall headroom is raised to -3dbfs. I do not believe a stereo foldown from 5.1 is created anywhere, except possibly in the viewer's set top box or receiver.

I've mixed for others but do not have enough knowledge to really know what they do in practice. I'd be surprised if any of them broadcast a 5.1 folddown, though. They always request and receive LoRo or LtRt mixes. To make a 5.1 folddown seems like extra work for no good reason. But, I don't really know.

[citysoundman]

Not sure if you saw this post http://duc.digidesign.com/showthread...&highlight=CAS
It's the audio from recent CAS seminar about TV broadcasting. Very informative.

[hef]

Thanks for the info Postman. and thanks for that link CitySoundMan. i listened to that CAS seminar, "What happened to my mix?"- very good info. the Dolby guy and the guy from Fox I found most interesting. Highly recommend it.

So yes the set-top boxes are doing the downmixing of the 5.1. And the stereo mix I create is only for the analog feed. I'm mixing a 1 hour special right now in 5.1. thank god its sounding pretty damn good listening to the folddown. although this nice 5.1 convolution verb isn't getting justice in stereo. hmmmmmmm. Will work on it tomorrow.....