[[email protected]]

On 2007-11-30 said:
"Scott Dorsey" wrote in message
...
I agree to send the best quality sound possible, but don't send
sound with too much dynamic range. Because the bad stuff will
happen, and it can be pretty bad. It may not happen until you
get to the cable company... it may not even happen until it gets
to the user's TV set.
mobile unitfibercontrol room/integration pointdigital
compression at uplinkdecompression at downlinkcable headend
modulatoryour home. I can't imagine what could happen. I listen
to stuff we did and not even recognize it sometimes, and if we try
to trace the problems, everyone denies doing any more than passing
it through. And then, of course, guess who gets the phone calls?
It gives me headaches sometimes.
I agree with Scott about the dynamic range. Somewhere some
automatic, well-intentioned box is going to try to bring up the
quiet parts, with ugly results.
Agreed, and I still don't understand why the heck none of
these people along the chain really seems to understand what
their automatic box is doing.
WHen I listen to television as just a consumer of the dreck
it usually gives one I"m usually in a motel room or
somewhere that is not going to offer the high end home
theater stuff.
Many of the dramatic shows I find are mixed so as the music
and sfx overpowers the dialogue. Music during actual musical
performances often isn't that great either, thanks to the
squish factor.

Best you can do is make sure you high pass, peak limit,
maybe just a smidge of comrpession to try to keep the
automatic dummy gain boxes downstream from mucking with it.
WEre I frank I'd almost say I had to have my mobile control
room though so as to be able to do a better job.



Richard webb,
Replace anything before the @ symbol with elspider for real
email address.

[Randy Yates]

writes:

On 2007-11-30 said:
"Scott Dorsey" wrote in message
...
I agree to send the best quality sound possible, but don't send
sound with too much dynamic range. Because the bad stuff will
happen, and it can be pretty bad. It may not happen until you
get to the cable company... it may not even happen until it gets
to the user's TV set.
mobile unitfibercontrol room/integration pointdigital
compression at uplinkdecompression at downlinkcable headend
modulatoryour home. I can't imagine what could happen. I listen
to stuff we did and not even recognize it sometimes, and if we try
to trace the problems, everyone denies doing any more than passing
it through. And then, of course, guess who gets the phone calls?
It gives me headaches sometimes.
I agree with Scott about the dynamic range. Somewhere some
automatic, well-intentioned box is going to try to bring up the
quiet parts, with ugly results.
Agreed, and I still don't understand why the heck none of
these people along the chain really seems to understand what
their automatic box is doing.

If we are talking about an analog NTSC television audio system, it is
performing spectrally-dependent dynamic range compression and expansion
in the difference channel.

This system was conceived by the old DBX corporation (remember
DBX-encoded records?) back in the early 80s when MTS was being
developed. The motiviation for using compression/expansion in the
difference channel was to combat the quadratic-law power spectral
density of FM discriminators in order to keep the stereo SNR shored up.

There is also preemphasis and deemphasis on the sum channel signal.

The best description I came across for the system is [tyler].

--Randy

@article{tyler,
title = "{A Companding System for Multichannel TV Sound}",
author = "Leslie B. Tyler and Mark F. Davis and William A. Allen",
journal = "IEEE Transactions on Consumer Electronics",
month = "November",
year = "1984"}

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