You can upmix stereo to 5.1 using the Fairlight DAW in Blackmagic Davinci Resolve and a 5.1 upmixing plugin.
DTS neural upmix and Penteo 16 pro can
- upmix stereo to 5.1 and 7.1.
- downmix to stereo from 5.1 and 7.1.
- upmix from 5.1 to 7.1
- downmix from 7.1 to 5.1
DTS neural upmix
- Analyzes phase and intensity to make a 5,1 mix. Can be overridden by the depth and width sliders.
- Is not officially supported in Resolve, but worked when I tested it.
Penteo 16 pro
- Is officially supported in Resolve by Penteo
- Uses a phaseless upmix.
It is important to have an LCR or 5.1 mix
HDCAM and DV video with stereo sound used to be played with Dolby Prologic or similar upmixing processing in cinemas. Stereo films were always upmixed to 5.1 to avoid using the left and right channels for dialogue. The center channel is the preferred channel to use for dialogue. If the stereo soundtrack is played in the left and right channels, 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.
Newer cinema sound processors may lack upmixing options like ProLogic, so for content with dialogue, it is important to upmix to 5.1 or LCR. An LCR upmix is safer to use if the cinema is not calibrated correctly.
For more info on upmixing read this post on how to upmix in Pro Tools.
Upmixing from stereo to 5.1 in Resolve
Add a stereo video or audio file to the timeline.
In the Edit module, add a stereo track to the timeline.
Choose 5.1 Bus Format
Go to Meny – Fairlight – Bus Format.
Choose Format = 5.1 and click on OK.
Add an upmixing plugin to the 5.1 bus in the Fairlight module
Go to the Fairlight module
Click on Effects and drag DTS neural Upmix Stereo/5.1 or Penteo to “Bus 1”.
Configure the plugin settings and test it.
DTS neural upmix
I use a standard 5.1 upmix with lower LFE that I found to work for most content in the calibrated auditorium I use.
I lower the LFE by -7 and test the 5.1 upmix with “play”.
In the plugin, you can see the upmixed result
In the inspector (top right corner) you can also change the settings and remove the plugin with trashbin.
If the sound is clipping or too low, you can adjust the level with “Normalize audio level.”
Right-click the audio and use “Normalize Audio level”
Normalization Mode Treu peak
to a setting that does not clip like -8.
In DTS neural upmix you can also enable the limiter to avoid clipping peaks.
You can adjust the loudness level for feature, trailer, or commercial levels. Read more about normalizing audio in this post.
If you want to run a limiter on the bus after the upmix plugin , you can add the built-in limiter to the bus after the upmixing plugin.
If you want an LCR upmix you could turn off the bass management and drag the depth slider to the front.
Penteo 16 Pro
After dragging the plugin to the bus, I click on the settings icon and change input and output order to L, R, C, LFE, lss, Rss, Lsr, Rsr,. This way, you will get audio files in the correct order like this:
In Penteo I choose discrete (hard center) and lower LFE by -7 (The default setting in Penteo is music, it has a wider sound with more phantom center sound.) The discrete 5.1 sound is similar to the default DTS neural upmix settings. This setting keeps dialogue in the center channel. The upmixing algorithm in Penteo is different so they do not match completely.
Exporting the 5.1 audio files
Go to deliver module.
When exporting sound files
Untick Export Video, if you are exporting only sound
Export Audio is ticked. Export 32-bit float
Codec: IEEE Float
Sample rate: 48000
Bit Depth= 32
Tick “Render one track per channel.”
Tick “Render as discrete audio Track.”
Output Track 1 = Bus 1 (5.1)
Click on “Add to render queue and “Render all”
The audio files will have this order
Optionally you can change the names from Test_A01.wav to Test.L.wav and so on.
If you want to analyze and normalize or process the 5.1 mix again in Resolve again, you can export the sound as an interleaved wav or QuickTime file:
Do not Tick “Render one track per channel.
Do not Tick “Render as discrete audio Track