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Frank Stearns Frank Stearns is offline
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Default Dealing with the TV Audio Signal Path

I'm doing a live Messiah recording for a new, major client, and was also asked, "by
the way, can you live-feed the tv people?"

Well, yeah, a monitor mix from a toy console under adverse conditions...

The local tv production folks assure me they "don't do anything" to the audio, but
who knows what "auto" settings are switched in on their gear and worse, what happens
when it leaves their hands and heads into the cable system. Shudder.

I am running a KM183 pair (with diffraction spheres) in AB stereo with 50 cm
separation. This is a departure from my usual MS config, but given that I can't
perfectly check the mechanical & electrical alignment "live" this should work well.
(In various tests here, and with a friendly competiter's D183s, I've been pleased
how this sounds -- mis-aligned MS, on the other hand, can be awful.)

Also running two solos, four spots in a rather large orchestra, and two choir
outriggers. The main pair should do most of the work, perhaps all -- depends on how
the room shapes up when it's full of people.

But here's the quest for wisdom... Should I pre-compress my feed to the TV folks in
the hopes that AGCs and other downstream manglers will be less inclined to trip? All
I have is a DBX 1066 that I've not yet modified. It's fairly clean (more so than the
RNC I used to have), but it's still a bit of a polluter.

Or, should I just get as uber-hi-fi as possible (such as schlepping out the bigger,
tweaked Soundcraft console - hate to move it), and let the downstream processing
take out chinks here and there as it will, and hope there's "enough left over" so
that it still sounds good in a typical mid-fi TV sound system, or is even passible
in a 3" speaker.

I told them the best way to do this is a post mix for TV, but there isn't time or
money for that. Sigh.

Any thoughts/experiences appreciated.

Frank Stearns
Mobile Audio
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Scott Dorsey Scott Dorsey is offline
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Default Dealing with the TV Audio Signal Path

Frank Stearns wrote:
But here's the quest for wisdom... Should I pre-compress my feed to the TV folks in
the hopes that AGCs and other downstream manglers will be less inclined to trip? All
I have is a DBX 1066 that I've not yet modified. It's fairly clean (more so than the
RNC I used to have), but it's still a bit of a polluter.


I always do. I tend to use an Aphex 108, but I have used the RNC as well.
The key is just to do some slow grainriding so that the AGC systems don't
go berserk.

The 1066 will be fine... you don't want to do so much compression that you
actually notice it. Also do a light high pass.

Or, should I just get as uber-hi-fi as possible (such as schlepping out the bigger,
tweaked Soundcraft console - hate to move it), and let the downstream processing
take out chinks here and there as it will, and hope there's "enough left over" so
that it still sounds good in a typical mid-fi TV sound system, or is even passible
in a 3" speaker.


The high pass will prevent the AGC stuff from going berserk, and the TV
guys will high pass everything more many times by the time it gets to that
3" speaker. You could add a little presence peak to make intelligibility
on a TV speaker a little bit better, but I don't normally bother.

Doing a super-hi-fi mix is probably not a good idea... if anything you
might want to do an extra-close-in mix that is less accurate than the
feed you have.

I told them the best way to do this is a post mix for TV, but there isn't time or
money for that. Sigh.

Any thoughts/experiences appreciated.


TV is bad.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
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William Sommerwerck William Sommerwerck is offline
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Default Dealing with the TV Audio Signal Path

I remember hearing a Bernstein live concert on PBS about 25 years ago that
was so compressed the dynamic range must have been less than 6dB. I stuck a
dbx expander on it, and the expander was unable to do anything.

I'd compress the hell out of it, and hold back a bit on the peak level of
the final compressed signal to reduce the chance of further compression down
the chain.

I don't think the people doing the broadcast care whether it sounds good,
just as long as the quietest passages are nice and loud, and the loudest
don't "blast".


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Richard Crowley Richard Crowley is offline
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Default Dealing with the TV Audio Signal Path

"Frank Stearns" wrote ...
I'm doing a live Messiah recording for a new, major client, and was also
asked, "by
the way, can you live-feed the tv people?"

Well, yeah, a monitor mix from a toy console under adverse conditions...

The local tv production folks assure me they "don't do anything" to the
audio, but
who knows what "auto" settings are switched in on their gear and worse,
what happens
when it leaves their hands and heads into the cable system. Shudder.


Does "live-feed the tv people" mean providing a stereo mix in
case the 6-oclock news people show up to shoot 5 minutes
of B-roll? Or is this a full-up live TV broadcast? Is it one of the
over-the-air channels in town, or is its some cable channel
(or "community access"?) Can you "characterize" the expected
audio path by listening to the channel beforehand? For example
one would expect a significant difference between the well-
funded local PBS operation vs. Portland Cable Access, vs.
one of the commercial stations with doubtful classical music
engineering talent.

I am running a KM183 pair (with diffraction spheres) in AB stereo with 50
cm
separation. This is a departure from my usual MS config, but given that I
can't
perfectly check the mechanical & electrical alignment "live" this should
work well.
(In various tests here, and with a friendly competiter's D183s, I've been
pleased
how this sounds -- mis-aligned MS, on the other hand, can be awful.)

Also running two solos, four spots in a rather large orchestra, and two
choir
outriggers. The main pair should do most of the work, perhaps all --
depends on how
the room shapes up when it's full of people.


Are you going to handle tracking and the live stereo mix
separately? Let me know if you need an A2 assistant :-)


But here's the quest for wisdom... Should I pre-compress my feed to the TV
folks in
the hopes that AGCs and other downstream manglers will be less inclined to
trip? All
I have is a DBX 1066 that I've not yet modified. It's fairly clean (more
so than the
RNC I used to have), but it's still a bit of a polluter.

Or, should I just get as uber-hi-fi as possible (such as schlepping out
the bigger,
tweaked Soundcraft console - hate to move it), and let the downstream
processing
take out chinks here and there as it will, and hope there's "enough left
over" so
that it still sounds good in a typical mid-fi TV sound system, or is even
passible
in a 3" speaker.


My experience has been that the closer you can get your feed
to what they are actually going to use, the less likely they are
to feel the need to "muck it up".

I told them the best way to do this is a post mix for TV,
but there isn't time or money for that. Sigh.

Any thoughts/experiences appreciated.


Let me know if you need any assistance (equipment or labor).
Any excuse to hear a good live local performance of Messiah. :-)
503-869-1741


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Randy Yates Randy Yates is offline
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Default Dealing with the TV Audio Signal Path

Frank Stearns writes:
[...]


Hi Frank,

I'm not a recording engineer but an electrical engineer (emphasis in
DSP) who has recently been involved with NTSC broadcast TV audio (the
decoder side, but this required intimate knowledge of the encoder).

Now I admit that I don't know what auxiliary processing a station does
to an audio signal (compression, etc.), but based on knowledge of the
BTSC (MTS) encoder my advice would be to simply feed it the best signal
you can. A good signal along with a good encoder/decoder can yield at
least 60 dB SNR these days, and you'll have a good 14.5 kHz of
bandwidth.

By the way, did you say whether this was an HD station or an old analog
station? An HD station should have even better performance what with the
use of digital source encoding, channel coding, etc.
--
% Randy Yates % "Though you ride on the wheels of tomorrow,
%% Fuquay-Varina, NC % you still wander the fields of your
%%% 919-577-9882 % sorrow."
%%%% % '21st Century Man', *Time*, ELO
http://www.digitalsignallabs.com


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Richard Crowley Richard Crowley is offline
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Default Dealing with the TV Audio Signal Path

"Goldsmiths" wrote ...
Wow, TV sound sure is getting ripped. I assure you that, at
least in mobile units, we care a hell of a lot about the sound.


Good to hear that at least some people in television care about
audio, but I fear that you represent rather a minority of the
industry.

But, unfortunately, most of the bad stuff happens after it leaves us.


Exactly the problem.

I agree with Randy; send the best signal you can.


That is one philosophy, but you are placing youself completely
at the mercy of whatever/whomever is downstream (vs. perfoming
some measures of pre-emptive processing under YOUR control.)

The old days of monitoring on-site with a 3inch Auratone are,
thankfully, just about gone.


I'm certain that big multi-million mobile units have halfway-
decent audio monitoring, at least for the audio control person.

There are enough viewers out there who actually have the gear to tell
the difference to make it worth your while.


I agree. But I believe that there are way too many people
running the distribution systems who still have the "3-inch
speaker philosophy" (and matching monitoring equipment :-)

If it will ultimately be HD/surround, or even just digital, it will be
worth it.


Indeed. But that is a big "IF", and seems unlikely when
audio for TV was only mentioned as an afterthought.

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david correia david correia is offline
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Default Dealing with the TV Audio Signal Path

In article ,
Frank Stearns wrote:

I'm doing a live Messiah recording for a new, major client, and was also
asked, "by
the way, can you live-feed the tv people?"

Well, yeah, a monitor mix from a toy console under adverse conditions...

The local tv production folks assure me they "don't do anything" to the
audio, but
who knows what "auto" settings are switched in on their gear and worse, what
happens
when it leaves their hands and heads into the cable system. Shudder.

I am running a KM183 pair (with diffraction spheres) in AB stereo with 50 cm
separation. This is a departure from my usual MS config, but given that I
can't
perfectly check the mechanical & electrical alignment "live" this should work
well.
(In various tests here, and with a friendly competiter's D183s, I've been
pleased
how this sounds -- mis-aligned MS, on the other hand, can be awful.)

Also running two solos, four spots in a rather large orchestra, and two choir
outriggers. The main pair should do most of the work, perhaps all -- depends
on how
the room shapes up when it's full of people.

But here's the quest for wisdom... Should I pre-compress my feed to the TV
folks in
the hopes that AGCs and other downstream manglers will be less inclined to
trip? All
I have is a DBX 1066 that I've not yet modified. It's fairly clean (more so
than the
RNC I used to have), but it's still a bit of a polluter.

Or, should I just get as uber-hi-fi as possible (such as schlepping out the
bigger,
tweaked Soundcraft console - hate to move it), and let the downstream
processing
take out chinks here and there as it will, and hope there's "enough left
over" so
that it still sounds good in a typical mid-fi TV sound system, or is even
passible
in a 3" speaker.

I told them the best way to do this is a post mix for TV, but there isn't
time or
money for that. Sigh.

Any thoughts/experiences appreciated.

Frank Stearns
Mobile Audio
--





One thing to add to the previous comments:

Make sure it mono's ok.






David Correia
www.Celebrationsound.com
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Scott Dorsey Scott Dorsey is offline
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Default Dealing with the TV Audio Signal Path

Goldsmiths wrote:
Wow, TV sound sure is getting ripped. I assure you that, at least in mobile
units, we care a hell of a lot about the sound. But, unfortunately, most of
the bad stuff happens after it leaves us. I agree with Randy; send the best
signal you can. The old days of monitoring on-site with a 3inch Auratone
are, thankfully, just about gone. There are enough viewers out there who
actually have the gear to tell the difference to make it worth your while.
If it will ultimately be HD/surround, or even just digital, it will be worth
it.


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...
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."
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[email protected] 0junk4me@bellsouth.net is offline
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Default Dealing with the TV Audio Signal Path


On 2007-11-29 said:
least in mobile units, we care a hell of a lot about the sound.

Good to hear that at least some people in television care about
audio, but I fear that you represent rather a minority of the
industry.
But, unfortunately, most of the bad stuff happens after it leaves

us.
Exactly the problem.

YEs, our unit is set up to interface with the TV folks and
we have good monitoring. I'm sure though that when it
leaves the uplink is the last time anything like what we
produce is going to be seen along the chain.
I agree with Randy; send the best signal you can.

That is one philosophy, but you are placing youself completely
at the mercy of whatever/whomever is downstream (vs. perfoming
some measures of pre-emptive processing under YOUR control.)

snippage
I agree. But I believe that there are way too many people
running the distribution systems who still have the "3-inch
speaker philosophy" (and matching monitoring equipment :-)

true enough, and then there are the cable head-ends which
even do more mangling.

If it will ultimately be HD/surround, or even just digital, it
will be worth it.

Indeed. But that is a big "IF", and seems unlikely when
audio for TV was only mentioned as an afterthought.

True enough. If it were me I'd high pass, peak limit and
try to keep downstream manglers from having a chance to grab
ahold of the signal at all.



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



Great audio is never heard by the average person, but bad
audio is heard by everyone.
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Frank Stearns Frank Stearns is offline
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Default Followup: Dealing with the TV Audio Signal Path

Thanks for all the suggestions and responses.

It comes down to resources (time and money). Ideally, I'd bring my mobile control
room or better yet, do a proper post-mix and lay it back to video. The first is not
logistically feasible; the latter is that old time and money thing. (Yet they'd like
to have a $10K+ audio job for $500. Yeah, I like to shop like that too.)

Fortunately, they agreed to recording the dress tonight and I'll be able to check a
number of things then, and even fiddle a bit back here in a good mix environment on
Saturday in preparation for the Sunday recording. At that time I'll get a rough comp
and EQ setting for the tv audio feed.

If there's any interest, I'll try to post a followup next week.

Thanks again,

Frank Stearns
Mobile Audio

Richard - thanks for your offer. I will try to call you later today; I'd be up for
perhaps a backup HD24 and maybe some backup preamp channels if you want to swap
those for admission.
--


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William Sommerwerck William Sommerwerck is offline
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Default Followup: Dealing with the TV Audio Signal Path

I assume you're familiar with this, but I'll mention it anyhow...

It's been my experience that performers play around 1dB to 3dB louder (at
peaks) during the performance than they do during rehearsal.


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Frank Stearns Frank Stearns is offline
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Default Followup: Dealing with the TV Audio Signal Path

"William Sommerwerck" writes:

I assume you're familiar with this, but I'll mention it anyhow...


It's been my experience that performers play around 1dB to 3dB louder (at
peaks) during the performance than they do during rehearsal.


Yup. Multiply that by 90 singers and 25 instrumentalists and you've got some serious
SPL. g

One nice thing about 24 bit digital is the nice big dynamic window. If (in my
old-timer's mind) the visualized mechanical VU only hits a -20 most of the time, no
worries. Lots of room for the 20 dB peaks!

And I'll be watching the comp's GR for the tv feed.

Thanks for the reminder,

Frank Stearns
Mobile Audio
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Bob Howes Bob Howes is offline
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Default Dealing with the TV Audio Signal Path


wrote in message
.. .

YEs, our unit is set up to interface with the TV folks and
we have good monitoring. I'm sure though that when it
leaves the uplink is the last time anything like what we
produce is going to be seen along the chain.


Ah, the dreaded "U" word...uplink. If the backhaul feed is, indeed, going
by satellite be very careful of where you sit your peaks. A lot of the
common satellite chains, both analogue and digital, are set to preserve RF
bandwidth rather than sound quality and clipping can onset as low as around
+10dBu (it varies a bit with frequency so I can't be more specific). We
used to have to have a hard limiter in circuit at about +8.

However, the good news is that the signal to noise, especially on digital
links, is pretty good so you can afford to back off the overall level a bit
to preserve dynamic range (at least until it hits the compressor at the main
transmitter!).

My caution on clipping aside, as a recently retired TV engineer (who DID
care about audio) I'll join the chorus of "just give them the best you can".

Bob


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Peter Larsen[_2_] Peter Larsen[_2_] is offline
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Default Dealing with the TV Audio Signal Path

Tim Perry wrote:

A radio engineer I knew had a favorite saying: TV people only notice
audio whan it isnt there.


I made a parallel recording of the opening of the Copenhagen Opera via FM
broadcast - via antenna, not via cable! - and via NICAM tv-sound. The
presenter mic to music mix ratio was idiotic on both transmissions. The TV
audio seems to be just as it was from the sound board. It still takes up a
lot of disk space on some harddisk.


Kind regards

Peter Larsen


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