Converting stereo to 5.1 in Pro Tools Ultimate with the Waves DTS neural upmix plugin

To convert stereo soundtracks to 5.1, I use Pro Tools Ultimate with the Waves DTS neural upmix.

The Waves DTS neural upmix is similar to choosing Dolby Prologic II on a cinema audio processor.

Sometimes I use the Nugen VisML plugin to check for LEQ(m) trailer TASA 85 dB and commercials SAWA 82 dB loudness levels.

Upmixing stereo with Waves DTS neural upmix and Izotope RX loudness control in Pro Tools Ultimate

To normalize the sound to a loudness and dynamics level that works with the Waves DTS neural upmix plugin and in a cinema, I use the Izotope RX loudness control Pro Tools plugin.

A normal TV stereo mix usually has a loudness around:
Between -integrated loudness -23 and -30
-max true peak -1 between -3

Web mixes has:
-integrated loudness between -10 and -17
-max true peak between 0 and +1


The target for a 5.1 mix is a sound level that can be played on a normal fader setting in the cinema. A normal target would be -28 and max true peak -3.

Note:
A -23 and -30 mix can sound the same in the cinema.
Example: If the -17 sound mix has a lot of music and effects and the -30 mix only has dialogue

More info:

A cinema sound mix usually has higher dynamics than a TV mix, the dialogue is mixed lower and the music and effects are louder than on a TV mix.

A -20 RMS pink noise signal played in the center channel is measured to 85 dbC at fader reference level 0. Some cinemas have set their fader level 0 to something else like -5.

A typical TV mix that is lowered to -30 will still have loud dialogue at fader level 0 or level -5 after running the upmixing plugin.

You can lower the integrated loudness even more to -35. But If the mix is very uneven with loud music and very low dialogue and has too much dynamics it can be difficult to do the 5.1 upmix. The true peak limiter can in some cases be used to lower sound peaks.

Running the Izotope RX loudness control audiosuite plugin

Click on the sound track
-Audiosuite
-Sound Field
-Izotope RX loudness control
-Choose a setting that fits like -28
-Choose a true peak setting that fits
-Analyze
-Render

Usually, TV and web mixes have even sound mixes, the sound mix is often like this example:
Integrated loudness -21.7 and true peak is 0.5:

When I lower the integrated loudness level to -28 I get a true peak of -6.8.
When the true peak is around -8 the DTS plugin will not clip. Sometimes you need to go to -10 to avoid clipping or use the true peak limiter to avoid clipping some peaks.

Upmixing to 5.1

Click on the sound track

INSERTS
Choose Multichannel plugin – sound field – DTS neural upmix (stereo 5.1) insert.

Say yes to making a 5.1 output
In I/O Choose 5.1 output

Click on the soundtrack and test the plugin


For a standard upmix I use the auto setting, and lower the LFE by -7. Bass management can be turned off if you don’t know if the cinema has calibrated the LFE channel correctly.

The DTS upmix plugin uses similar algorithms as Dolby Surround/Prologic to make the surround channels. Professional TV mixes are usually OK to upmix to 5.1, but with amateur mixes, LCR upmixing can be the safest choice.

Upmixing to LCR

When doing an LCR mix, turn the Bass Management off, and slide the Depth slider all the way to the front.

Bounce to Disk

To save the 5.1 mix, I use Bounce to disk. On SSD disks, it is around 40x speed.

-Click on the soundtrack
-File-Bounce-To disk

Extra step: Run the RX loudness plugin again

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 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 a integated setting that fits like -28
-Choose a true peak setting that fits like -3
-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 get it closer to the LEQ(m) trailer TASA 85 dB and commercials or SAWA 82 dB loudness levels.

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 set 27 SAWA 82 dB or 28 TASA 85 as the default

-Loudness
-Analyze

More info:

LCR upmixing is the safest choice if the sound mix is in stereo and you can’t test it in the cinema. The problem with using Left/Right stereo mixes on DCPS is that stereo has been used in cinemas.

Cinemas first used mono sound in a center channel.

Dolby Stereo in the 70/80s used 4 channels extracted from the stereo track: Left, Right, Center, and Mono Surround.

5.1 Dolby Digital, DTS, and SDDS in the 90s used discrete Left, Right, Center, LFE, Ls, and Rs channels with compressed sound.

Today digital cinema uses uncompressed 5.1, 7.1, and Dolby Atmos.

DCP specifications for film festivals often say that the sound must be 5.1 or specify that a film should have at least an LCR mix with dialogue in the center channel.

Without a center channel, the dialogue will sound like it comes from the left side if you sit on the left side of the auditorium, and the right side if you sit on the right side. If you sit in the center, you can get a phantom center, but only some seats will get this effect.

When left and right speakers play the same sound, phase cancellations between the two sound channels may cause an unpleasant effect. If you turn your head, the sound seems to be moving inside your head.

In 5.1 mixing, there is a best common practice to avoid using the same sound in two different channels at the same time to avoid these phase issues.

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.