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Author Topic: TASA - A movie theater's point of view on loudness  (Read 3411 times)

Tomas Danko

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TASA - A movie theater's point of view on loudness
« on: March 31, 2009, 10:58:48 am »

I'm not sure if this has been covered already here, but I thought it was interesting as a comparison to the loudness war on audio CD's.

http://www.filmjournal.com/filmjournal/content_display/news- and-features/features/technology/e3i4f087b1aeac6f008e9120e10 3361fb62

Since we cannot control the listening level in every home/car/iPOD something similar can probably not be done, but it's still nice to read about action taken against the loudness war.
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Barry Hufker

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Re: TASA - A movie theater's point of view on loudness
« Reply #1 on: March 31, 2009, 11:51:38 am »

Thanks for sharing that.  I've not seen it before.

But I wonder if the problem is solved at all.  For their specifications are they talking average or peak?  For instance when watching TV, the program may peak at 85(unit-of-measure) while the commercial averages 85 (unit-of-measure), resulting in a louder sounding commercial.  It's a start and a standard...

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Tomas Danko

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Re: TASA - A movie theater's point of view on loudness
« Reply #2 on: March 31, 2009, 12:21:51 pm »

Barry Hufker wrote on Tue, 31 March 2009 16:51

Thanks for sharing that.  I've not seen it before.

But I wonder if the problem is solved at all.  For their specifications are they talking average or peak?  For instance when watching TV, the program may peak at 85(unit-of-measure) while the commercial averages 85 (unit-of-measure), resulting in a louder sounding commercial.  It's a start and a standard...




Dolby has been trying to introduce apparent loudness metering for a couple of years, including algorithms to measure how clear the dialogue is in comparison to the rest of the audio mix. Other than that, it's usually RMS that's being mentioned unless something closer to reality can be estimated using the Dolby methods.
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minister

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Re: TASA - A movie theater's point of view on loudness
« Reply #3 on: March 31, 2009, 03:13:01 pm »

Tomas Danko wrote on Tue, 31 March 2009 11:21

Dolby has been trying to introduce apparent loudness metering for a couple of years, including algorithms to measure how clear the dialogue is in comparison to the rest of the audio mix. Other than that, it's usually RMS that's being mentioned unless something closer to reality can be estimated using the Dolby methods.

Dolby has introduced loudness metering.  I have never heard any Dolby Engineer mention RMS, nor do they use RMS as a measuring tool.

For Broadcast, the LM100 used the LEQ(a) [updated to meet the new ITU-R BS.1770-1 standard] to measure which measured Dialogue levels (not clarity) as separate from a mix over time.  It has been modded to now conform to   The idea being that most complaints from viewers are that the dialogue is too loud.  Some networks require a LM100 (or the Dolby Meter plug-in) measured dialogue norm value of a certain amount.  This is broadcast.  Amazing thing is, you cannot fool the LM100, it really has Dialogue Intelligence.

For film, there have been standards for Trailers and Commercials for a while.  It is measured by the Dolby 737, which measures LEQ(m).  Trailers is 85 LEQ(m); Commercials is 82 LEQ(m).  This is true for Europe too.  Go over that number and your spot or trailer is kicked back.  The TASA standard was adopted in 1997.

relevant links:

http://www.tasatrailers.org/whatis.html

http://www.sawa.com/prodinfo.php

    http://www.dolby.com/professional/pro_audio_engineering/dolb y-media-meter-overview.html
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tom hambleton C.A.S.
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minister

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Re: TASA - A movie theater's point of view on loudness
« Reply #4 on: March 31, 2009, 03:21:12 pm »

Barry Hufker wrote on Tue, 31 March 2009 10:51

Thanks for sharing that.  I've not seen it before.

But I wonder if the problem is solved at all.  For their specifications are they talking average or peak?  For instance when watching TV, the program may peak at 85(unit-of-measure) while the commercial averages 85 (unit-of-measure), resulting in a louder sounding commercial.  It's a start and a standard...



Barry, the 85 (unit of measure) refers to reference level.  Specifically Steady-State Pink where -20 dBFS PINK = 85 SPL (C weighted, Slow).  I outlined the loudness measures in a previous post.

The problem is ongoing.  Dolby and others are working on it.

One problem in a Theater setting is not every room is calibrated right, or, the Theater manager thinks that movies are too loud, so they turn the monitor level down....so now the mixers mix louder, and so......

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Tomas Danko

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Re: TASA - A movie theater's point of view on loudness
« Reply #5 on: March 31, 2009, 03:28:31 pm »

minister wrote on Tue, 31 March 2009 20:13

Tomas Danko wrote on Tue, 31 March 2009 11:21

Dolby has been trying to introduce apparent loudness metering for a couple of years, including algorithms to measure how clear the dialogue is in comparison to the rest of the audio mix. Other than that, it's usually RMS that's being mentioned unless something closer to reality can be estimated using the Dolby methods.

Dolby has introduced loudness metering.  I have never heard any Dolby Engineer mention RMS, nor do they use RMS as a measuring tool.

For Broadcast, the LM100 used the LEQ(a) [updated to meet the new ITU-R BS.1770-1 standard] to measure which measured Dialogue levels (not clarity) as separate from a mix over time.  It has been modded to now conform to   The idea being that most complaints from viewers are that the dialogue is too loud.  Some networks require a LM100 (or the Dolby Meter plug-in) measured dialogue norm value of a certain amount.  This is broadcast.  Amazing thing is, you cannot fool the LM100, it really has Dialogue Intelligence.

For film, there have been standards for Trailers and Commercials for a while.  It is measured by the Dolby 737, which measures LEQ(m).  Trailers is 85 LEQ(m); Commercials is 82 LEQ(m).  This is true for Europe too.  Go over that number and your spot or trailer is kicked back.

relevant links:

http://www.tasatrailers.org/whatis.html

http://www.sawa.com/prodinfo.php

    http://www.dolby.com/professional/pro_audio_engineering/dolb y-media-meter-overview.html


You are correct, of course. I skipped some wording there, and refered to generic discussions that talks about RMS and not peak values outside of all-things-Dolby. The reason I mentioned Dolby in the first place was because, as you point out, there are very good standards within broadcast and film as opposed to CD audio.
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Axon

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Re: TASA - A movie theater's point of view on loudness
« Reply #6 on: March 31, 2009, 06:03:22 pm »

LEQ is an RMS-based metric.

It's also worth noting that ReplayGain is explicitly based on the film model - its calibration is against pink noise at some assumed reference level. The loudness model is not LEQ(m), though.
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minister

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Re: TASA - A movie theater's point of view on loudness
« Reply #7 on: March 31, 2009, 09:59:17 pm »

Axon wrote on Tue, 31 March 2009 17:03

LEQ is an RMS-based metric.

The two are not interchangeable.  LEQ measures linear energy average; RMS is non-linear in that it looks at the present as "more important" than the past.

Axon wrote on Tue, 31 March 2009 17:03

It's also worth noting that ReplayGain is explicitly based on the film model - its calibration is against pink noise at some assumed reference level.
Theatrical playback is assumed to be the same as the A-Chain (or mix stage) playback. This is one of the few arenas where there is some standardization of SPL.  There is no dispute there....not sure of your point.

Axon wrote on Tue, 31 March 2009 17:03

The loudness model is not LEQ(m), though.
The loudness model with respect to Cinema commercials and Trailers most certainly IS LEQ(m)!  One has to pass their mix through a Dolby 737 box to meet the LEQ(m) loudness rating.

LEQ(a) is being use in Industrial noise measurement and Broadcast loudness measurement.


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tom hambleton C.A.S.
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