Sound Test in Theatre Issue

Anything and everything to do with DCP-o-matic.
bee_charmer
Posts: 10
Joined: Wed Jun 19, 2024 7:18 pm

Sound Test in Theatre Issue

Post by bee_charmer »

Hi there! Took my DCP to a cinema to test it out, and had a weird issue. Not sure if it's me or the cinema though. My prores file is stereo, and I created the DCP as "8 - 5.1/HI/VI", since I was given the warning that anything less might present a QC error. The audio in the content tab shows only the left and right speakers as green...the rest white...which makes sense since it's a stereo mix.

So the issue I had, hard to describe but if you were sat dead centre in the theatre, there was a really weird kind of dead zone, or like weird quiet in one ear, and sound in the other. I'm assuming this is because there was nothing coming out of the centre speaker possibly? I don't know. It was strange. And I'm wondering, is it my file? Or the theatres speaker set-up? The projectionist couldn't explain it. Any thoughts?

If it's of any help, I have played this film at a festival previously. I sent them the prores quicktime and they created the DCP. So there were no issues at that screening. This DCP I created was from the same prores quicktime file. Not sure if that's at all relevant.
Carsten
Posts: 2804
Joined: Tue Apr 15, 2014 9:11 pm
Location: Germany

Re: Sound Test in Theatre Issue

Post by Carsten »

Depending on that auditoriums speaker layout, this is likely to happen with stereo-only programs. That's why 'real' cinema sound should always contain L/C/R.

Cinemas will not upmix stereo DCPs to their full speaker set.

You don't need to create an 8ch DCP - 5.1/6ch is okay as well (even 2ch for stereo). The 8 or 16 channel hint is towards certain workflow habits of commercial DCP mastering services. You may want to test the LCR upmixer in DCP-o-matic.
bee_charmer
Posts: 10
Joined: Wed Jun 19, 2024 7:18 pm

Re: Sound Test in Theatre Issue

Post by bee_charmer »

Okay, thanks Carsten. In reading some of the other posts in the forum, I think I figured out that I need to be using the mid-side decoder to create that LCR mix. Is that right? So, when I choose 6 - 5.1, and turn on the mid-side decoder, I can see in the audio levels graph the three channels...Left/right looking the same level, and now a centre channel that is louder than the L/R. Is that correct for what I need? The "content" audio tab shows just left and right channel as green. Is this correct?
Carsten
Posts: 2804
Joined: Tue Apr 15, 2014 9:11 pm
Location: Germany

Re: Sound Test in Theatre Issue

Post by Carsten »

This is correct.
bee_charmer
Posts: 10
Joined: Wed Jun 19, 2024 7:18 pm

Re: Sound Test in Theatre Issue

Post by bee_charmer »

Okay, wicked awesome. Will do, and test again. Thank you so much once again for the help!!