editing Urgent - Separate Mix for Theatre and DVD?

[Audio_Dan]

Hi everyone, new here and really hoping some of you can help me please.

I've been mixing my first feature film a while now and it's almost complete. It was initially set for release on DVD however now some people want to screen it theatrically abroad too and it will be entered into some festivals. I'll have to do an M&E mix for foreign dubbing but will I have to remix the whole film again and have a separate mix for the DVD and Theatre?

If so what would need to be different between the mixes? Is it simply a smaller dynamic range for DVD?

I've been mixing in a small treated room with near fields and sub calibrated to 79dB although I've turned up to 85dB now and then to test the mix. I've generally mixed by ear but mixed the dialogue to peak no louder than -18 (Which feels right with the rest of the film). Loudest SFX peak around -3dB (Having real trouble with getting it lower as film contains huge bombing/destruction) and one bomb just doesn't sound loud unless it reads louder than others on the meter, is this ok? Thinking it must be some psychoacoustic effect with frequency but EQ has made little difference.

One of the main things I'm a bit puzzled by tho is where the dialogue should average. I've read many things regarding Dialnorm etc however the general conversation dialogue in the film fluctuates from around -28dB to -18dB.


Thanks for your time with this I really hope someone can clarify these things for me

Cheers,

Dan

 

[audiosf]

Hi Dan,

Yes, it sounds like your setup and approach is correct. Typically a theatrical mix is done first, followed by the home theater mix, which, as you have pointed out, has a smaller dynamic range with the room set to 79dBSPL.

I typically mix by ear and let the peaks fly wherever they need to. Sometimes dialogue screams peak over -16dBFS - it all depends on the content/scene. "Mixing by numbers" leads to a boring/flat mix and it often limits and restricts the dynamics. Some of my SFX peaks go up to -1dBFS. I don't really look and obsess over meters when I mix.

There is a great sticky on dialnorm in the GearSlutz post production forum. Everything you'll need to know about it is there.

Best,

Ryan

 

[AudioPostExpert]

Yes, it sounds like your setup and approach is correct.

Hi Ryan and welcome. Sorry to start on a negative note but I'm going to have to disagree with you on this one. I definitely agree with your "mixing by numbers" sentiments though.
-----------------------------------------

Hi Dan and welcome too! There's a number of points and questions you've asked which lead me to believe you might be "in over your head" on this one. If you were doing a theatrical mix for a low tier film festival, you would probably get away with it but it seems you're working for a commercial client, in which case I think you could run into some serious problems! To address your questions:

I'll have to do an M&E mix for foreign dubbing but will I have to remix the whole film again and have a separate mix for the DVD and Theatre?

An M&E mix is not a separate mix as such, it's an identical mix just without the dialogue stem (or usually without dialogue stem). You might get away with a separate (slightly different) M&E mix depending on the country and distributor or, it might get kicked back.

I've been mixing in a small treated room with near fields and sub calibrated to 79dB although I've turned up to 85dB now and then to test the mix.

Hmmm, sounds like you're using a bass managed music system, which will cause you problems. The correct theatrical calibration is: Front speakers @ 85dBSPL, Surrounds @ 82dBSPL and Subs; in-band calibrated to the same as the front speakers and then boosted by +10dB. However, these calibration figures are only appropriate for a commercial (cinema sized) theatrical mix stage and 85dBSPL will not work in a small room! There is no standard calibration for a small room as it's not considered appropriate/possible to mix a theatrical feature in a small room.

Although you haven't specifically mentioned it, I assume you are making a 5.1 mix rather than a 2 channel (LoRo) stereo mix? Just in case, be warned that stereo (LoRo) is NOT an acceptable commercial theatrical audio format.

I've read many things regarding Dialnorm etc however the general conversation dialogue in the film fluctuates from around -28dB to -18dB.

OK, that's confused me a bit! Dialnorm is a metadata parameter for Dolby Digital, which indicates the film you're working on will be distributed on 35mm film. However, the dialnorm parameter only exists in the consumer version of Dolby Digital (for DVD, BluRay and HDTV) not the theatrical version, so anything you've read about dialnorn almost certainly does not pertain to theatrical mixes. Also, if it's being distributed on 35mm film with a DD mix, you will not be able to create the mix! It can only be done by a Dolby certified theatrical mix stage and additionally, the film's producer/s will have to negotiate and buy a license from Dolby themselves to use the DD technology.

Regarding the dialogue levels you've mentioned, there's no way to know, as Ryan in effect stated, it all depends. The theatrical workflow is; first an accurately calibrated mix stage and then mixing by ear (rather than by meters), as dBFS levels don't necessarily tell you anything about loudness.

If so what would need to be different between the mixes? Is it simply a smaller dynamic range for DVD?

Dynamic range maybe the most obvious difference but it's not the only one. There is usually an EQ difference, due to the theatrical x-curve and the different response of horn based theatrical speakers. There's the 3dB difference in the surrounds and the significant difference in the sub/LFE channel (relative to music systems). There's a difference in the "width" of the mix, due to the front left and right speakers being 20 or more feet apart. And then there's the potential phase and/or perception issues as theatrical sound systems don't have independent left and right surround speakers but an array of "diffuser" speakers all the way around the walls.

In short, it's not feasible/possible to create a commercial theatrical mix in a small room. If it were, there wouldn't be any large (expensive) commercial mix stages! If you've backed yourself into a corner and now have no choice, then I'd very strongly recommend you at least hire a commercial theatrical mix stage for a few hours and have your mix checked by a professional theatrical Re-recording Mixer.

Again, sorry, not exactly the answers you were probably hoping for, but it's better to be honest IMHO and address the problems before it's to late to do anything about them.

G

 

[Audio_Dan]

Thanks for your input guys!

That's good to know about some of your SFX peaks hitting -1dB Ryan. I have a couple that hit -2dB and was worried that might be unacceptable. Thanks for the info about that sticky too.

The film is in stereo and was initially planned for DVD and festivals etc, the possibility of theatrical plays is a later development. As Ryan says, typically a theatrical mix is done first, which I would expect, but due to the circumstances it's a little backwards. I guess it's their choice whether they're happy to screen a stereo film theatrically.

My main concerns are with making sure the mix is not too loud or quiet and dialogue is intelligible, not over the top or unheard.

When I mentioned Dailnorm I meant if they want DVD encoding, if I need to inform the producers of the average dialogue level for encoding the metadata with a DRC such as Film Light if needed, or does this only apply to 5.1 mixes and over?

I'm a bit unsure still about how to deduce what the dialogue level is tho and how that would be applied in the encoding process. Even if I don't have to do any of that I'm interested. Is it literally the level in between the quietest and loudest spoken word throughout the film?

I'll check out that Dialnorm sticky Ryan it might help me out.

Thanks,

Dan

 

[AudioPostExpert]

I guess it's their choice whether they're happy to screen a stereo film theatrically.

Not necessarily! If they are screening in standard commercial cinemas most likely they will distribute on DCP, the standard for DCP is defined by DCI and/or SMPTE, both require a minimum 3.0 mix, although 5.1 is more common. You might want to ask the producer about this urgently! As I said, stereo is not a theatrical format.

Something else you need to check is frame rates, which are different between DVD and theatrical!

My main concerns are with making sure the mix is not too loud or quiet and dialogue is intelligible, not over the top or unheard.

That is obviously the first consideration. Unfortunately the only way to be sure is by mixing on a calibrated theatrical mix stage.

When I mentioned Dailnorm I meant if they want DVD encoding, if I need to inform the producers of the average dialogue level for encoding the metadata with a DRC such as Film Light if needed, or does this only apply to 5.1 mixes and over? I'm a bit unsure still about how to deduce what the dialogue level is tho and how that would be applied in the encoding process.

I can't see why they would want to encode the film with DD. For 5.1 they would have to use DD (or DTS) but for stereo they would surely just leave it as PCM?

I believe dialnorm does apply to stereo, although I've only got experience with 5.1. We used to use Dolby Media Meter to measure the dialnorm but these days we just measure the integrated loudness of the mix (with one of the many loudness meters), then that value used for the dialnorm setting. That would be -23 for HDTV and the convention for DVD is -27 (although that convention is not enforced and sometimes not adhered to).

G