Best Practices for a Quick Mix of Stereo to 5.1

Hi all,

I just had a short film get accepted into a local festival (yay!) and need to export in a particular format for them: MP4, 2K, 5.1 audio

NB: I'm not a professional and have kind of burned through my audio post production budget, so my goal is to do something "quick and dirty" myself to export something that meets the specs.

Previously, I had just uploaded to Vimeo and my "final cut" timeline has 3 tracks: one for all Dialog, one for Music, one for FX.

These are all stereo tracks.

I've been looking around at the BlackMagic Fairlight Manual and YouTube channel getting my head around how to export 5.1 sound from Resolve.

It seems like best practice is to:

- send the Dialog (and only the Dialog) to Center
- only send a handful of the most important FX to LFE

And then I guess you spread around the Music and FX around Left, Right, Left Surround, and Right Surround.

(1) Does this seem like a reasonable approach?
(2) If so, if I have a stereo music track, would I just copy the clip from this into 4 mono tracks (one for Left, Right, Left Surround, and Right Surround)? And then same for FX (assuming I didn't want to do any fancy panning)?
(3) I just watched a great tutorial on "downmixing" from 7.1 to 5.1 and stereo and I'm wondering if anyone has useful links on best practices for going the other direction.

Hopefully that makes sense -- lmk if anything needs clarification. Many thanks in advance for any help / tips / links.

The biggest challenge will be the monitoring environment. Are you able to monitor the 5.1 mix (or an LCR)?

Will the festival accept the stereo mix?

In absence of a full 5.1 monitor do not touch the LFE.

If you have no way to monitor your mix in 5.1 (or at least have a short proof screening in your local theater), I would send the Dialog to Center and everything else to LR as it is.

Johannes

@Johannes

I'm going to see if I can get to b&h to get some speakers and an audio interface before the file submission deadline, but if I cannot, I'll do as you say: I'll do as you say: "If you have no way to monitor your mix in 5.1 (or at least have a short proof screening in your local theater), I would send the Dialog to Center and everything else to LR as it is."

@SeldomSeenKid

Understood on the LFE

@Reynaud

I emailed the festival to see if they will accept stereo mix but no reply yet.

Thank you all for your help / advice!

I've never done it, but there are Upmix plug-ins out there. (Stereo to 5.1 or 7.1)

Essentially they do a Dolby Surround-type of processing on the stereo original and, much like a Home Theater receiver, send the signal to the proper tracks.

Last year I helped a friend for a 5.1 mix. I found him an older Yamaha 5.1,,, 7.1 receiver with HDMI in for $80. He already had some LCR speakers, so he bought some book shelf rear speakers for a great price that I believe he found on Facebook, Craigslist. You don't need high powered rear speakers in your case.

I took the HDMI out from his RTX 3070 and wired the HDMI cable to his Yamaha for the audio. Bang, he was in business. This was on a PC.

Essentially they do a Dolby Surround-type of processing on the stereo original and, much like a Home Theater receiver, send the signal to the proper tracks.

Kind of. An AVR with Dolby PL or similar needs a proper encoding scheme to drive the signal to the right track, basically an LtRt encoded stereo signal. If fed with a pure LR signal, the plug-in can only guess where to send the signal, so you get a random result.

My advise is the same as Johns. Get yourself a 5.1 receiver, feed it via HDMI and re-mix your project. For best possible results put all speakers in the same distance around you and calibrate the output to cinema standard (I forgot the numbers). You can use your smartphone and an app like NIOSH SLM to do the dB measurement.

One thing, which can be a bit tricky is to upmix the music if you don't have multitracks but just a 2.0 source. A cheap (yet free) solution is the Rode Soundfield plug-in. Originally designed for transfering ambisonic formats to x.1, it also works with stereo signals. Throw it on a 5.1 track, switch the output to 5.1, put your stereo music on the first two channels and voila.