Originally Posted by hokiewolf
Alan, I live outside your station's viewing area, but experienced a similar problem recently with a recording of L&O. The engineers at my local NBC affiliate have remained mum...I would appreciate it if you could take a moment and explain to the group(or at least PM me) how this happens. I'm not nitpicking or fussing...just curious as to the technology and growing pains involved with the conversion to DT and HD. Someone theorized in my local forum that the problem was with an audio switcher at the station. I'm wondering if there's an audio setting on my EZ17 DVD recorder that could compensate for this if it occurs again.
OK, I was way to tired to type last night. Here you go.
The show that aired later with the audio problems was our fault - it was on oversite that after the fact we said, duh.
Our plant has 2 worlds - the SD world ( in which we run SDI w/ embedded audio - that is the audio is contained with the video and using a single coax, we can send video and audio signals to things like tape machines and servers) and the HD world.
We have an 128x128 SD router. That is 128 inputs that can be mapped to any of the 128 outputs. This is SDI w/ embedded audio.
The HD world we started with a 16x16 router - however it is actually 2 routers. A 16x16 video router and a 16x16 audio (AES - digital audio) router. This side of the plant is NOT using embedded audio. So to the tape machines, say to record CBS in 5.1 we need a video cable and 3 audio wires (AES audio is in pairs - cable 1 - ch 1/2 cable 2 - ch 3/4 cable 3 ch 5/6).
Up until the first of Dec. hd record and playback were done by 2 HD tape machines we have. The first of December we added to our on-air HD server by doubling the drive storage and adding HD servers.
These servers can take HD w/ embedded audio ( which we don't run - YET )
or HD with AES audio ( which is the way the plant is wired currently).
However, unlike the tape machines with can handle 8 AES pairs, the server only handles 2 pairs. Audio 1 - ch1/2 Audio 2 Ch 3/4.
Hence the oversight. We said now that we have the server, we will just record the show and playback off the server.
Well for 5.1 audio, I need audio 1/2 3/4 5/6. I can only input 1/2 3/4.
5/6 get left out and that is where the Center mix is (5) and LFE (6).
OOPS. WE just weren't thinking. The gear came in this week to allow me to replace my router to a much larger one and go embedded audio on HD shortly.
I hope this makes sense!