Normalize sound for DCPs

There are three common sound levels on DCPs:

Feature Cinema mix loudness level
-85dB SPL standard reference level

LEQ(m) trailer TASA 85 dB loudness level
Normally between -13 and -15 Integrated loudness

LEQ(m) commercials SAWA 82 dB loudness level
Normally between -20 and -22 Integrated loudness

Video files can have different loudness levels:

Default RX 9 loudness control level
-Integrated loudness -24 (+/-2)
-Max true peak -1
-Short-term -18

Netflix -27 LKFS BS. 1770-1 level
-79dB SPL or 82dB SPL standard reference level
-27 LKFS/Integrated loudness (+/-2)
-Max true peak -2

BS. 1770-2.3.4
-Integrated loudness -24 (+/-2)
-Max true peak -2
-Program loudness gate

EBU R128 TV stereo mix
-Integrated loudness -23 (+/-0,5)
-Max true peak -1
-Program loudness gate

Video streaming Delivery (RX 9)
-Integrated loudness -14 (+/-2)
-Max true peak -1
-Program loudness gate

To normalize the sound to a cinema sound level
I use the Izotope RX loudness control Pro Tools plugin
or
Izotope RX 9 Standard

If the sound is in stereo I normalize the sound to a level that will not clip in the Waves DTS neural 5.1 upmix plugin, usually around:
-Integrated loudness 24 to -35
-Max peak -8.

See this post for more info on upmixing to 5.1

Then I normalize the 5.1 mix again to a level that will fit the Feature, Commercial, or Trailer level.


Manually analyzing loudness in RX 9

When analyzing the loudness levels I play the clips in RX 9 and watch the RMS value when playing dialogue parts and loud parts. I check if the RMS levels between dialogue and loud parts are too high.

I run Waveform statistics to see:
-Total RMS level /integrated loudness
-True peak level
-Max RMS level

This dialogue part I am playing has an RMS level of about -14 in the sound level meter, which is close to the total RMS level of -12.29 dB and Integrated loudness of -12.2 LUFS. True peak is -1 and max RMS is -3,05. The dynamics of the mix seem OK and can be normalized to different loudness levels. If the RMS levels of dialogue were -35 and the loud parts were -3 the dynamics would be too high.

Note:
It is best to check the mix with 5.1 loudspeakers to detect phase problems like when someone has stretched the sound without phase sync. Or errors in like a doubling of the effects stem/part.

Normalizing in Pro Tools Ultimate with the Izotope RX Loudness Control Audiosuite Plugin

  • Click on the sound track
  • Audiosuite -Sound Field -Izotope RX loudness control
  • Analyze
  • Choose a setting that will not clip like -28
  • Choose a true peak setting that fits like -8
  • Analyze
  • Render

Example

This sound mix has a loud even mix:
-Integrated loudness is -21.7
-True peak is -0.5

When I lower the integrated loudness by 6.3 dB to -28 I also lower the true peak by 6.3 d dB to -6.8.

Note:
The True Peak limiter can in some cases be used to limit the peaks. If I had set the true peak limiter to -8, it would have lowered the peaks from -6.8 to -8.

Normalizing the stereo sound track in Izotope RX 9 Standard

In Izotope RX 9 standard you can analyze the Audio Track and normalize it to a level that fits the upmixing plugin. It will also use a true peak limiter on audio peaks if you choose to.

In Modules – Loudness control you can choose different loudness levels

If the loudness level was Video streaming service:
-Integrated loudness -14
-True peak -1

Lowering the integrated loudness target by 10 decibels to -24 will get you a true peak of -11.
Now the sound is normalized for the plugin and will not clip in the upmixing plugin.

Extra step: Run the RX loudness plugin again on the bounced 5.1 mix

You can run the RX loudness plugin again on the bounced 5.1 mix to get it closer to the original loudness level or a set target loudness level.

  • Add track
  • Track – new
  • 5.1
  • Drag the bounced 5.1 mix to the 5.1 track
  • Audiosuite – Sound Field – Izotope RX loudness control
  • Click on the 5.1 track
  • Choose an integrated setting that fits like -27
  • Choose a true peak setting that fits like -2
  • Analyze
  • Render
  • Go to clips
  • right-click clip
  • export clips as files.

Extra step: Use Nugen Visml to see the LEQ(m) level

You can run the Nugen Visml loudness plugin on a 5.1 mix to see how it compares to the LEQ(m) trailer TASA 85 dB loudness level
and LEQ(m) commercials SAWA 82 dB loudness level.

Note:
A trailer typically reaches LEQ(m) 85 dB with some dialogue that can range from quiet (-24 RMS) to loud (-12 RMS), some quiet parts, and some loud parts with a lot of music/effects.

  • Add track
  • Track- new
  • 5.1

Drag the 5.1 mix to the 5.1 track

  • Click on the 5.1 track
  • Audiosuite – Sound Field – Nugen Visml2
  • Click on options and choose SAWA 82 dB or TASA 85 db
  • Loudness
  • Analyze



Note:

Some cinemas have set their reference fader level 0 to something else like -5 or -10.
With the fader at reference level 0 (7 on Dolby), a -20 RMS pink noise signal played in the center channel is measured to 85 dbC in the center 2/3 from the screen.
With a -20 RMS pink noise DCP and decibel app on a phone, it is possible to check that the reference level is correct.
If you need to set the fader to +10 to achieve 85 dBc in the decibel app you know the reference level is actually +10.

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