PPM levels help for theatrical mix..urgent-ish!

[joe945]

Hey everyone..

I'm doing a theatrical mix (my first feature film!) for a film festival screening in a cinema next week...& panick's setting in!!

I've learned a hell of a lot from reading up on here so just wanted to say a massive thank you to all that contribute so much..i first posted over a year ago when i took on this project, for which i've done all the post work, and would've been totally lost without everything i've picked up from this forum.

Anyway..i've done the dvd mix & that's been well received, but i've now got a whole new set of things to get my head around with the theatrical mix & there's not been a whole lot of time to do a new mix for the screening because it was only organised recently.

Bascially what i've done, after reading up on here & the DUC forum, is calibrated my listening position (fireface 800 da straight to adam p22a's - with plenty of acoustic treatment in a small room) to 83dbc - slow on an SPL meter playing back pink noise @ -20dbfs

I've been mixing by ear from there with the output of nuendo limited to -10dbfs (as i didn't know what peak level was required when i started the mix) & am barely touching the limiter on the loudest sections. I'm now pretty happy with how it sounds in my room & the mix has more dynamic range than the dvd mix.

I need to prepare the stereo wav for a post house that's doing the layback to digibeta and just wanted to check if i've missed anything.

The people at the post house have asked me to ensure that peaks don't exceed 4PPM (UK), but since i'm working itb in dbfs i've no idea what this translates to..from what i can gather it's -18dbfs? Is that right? If so does that mean that i need to trim / set the limiter for the whole mix down to peak at -18dbfs? I've also been asked to add 5 seconds of -18dbfs 1khz tone onto the start of the mix, presumably so they can calibrate the digibeta deck to the right level?

The mix i've done so far, which is set to peak at -10dbfs has an average overall RMS of -30dbfs (no way of doing dialogue rms), does that sound about right or am i being a bit too conservative?

Any advice would be really appreciated as i've only got the until sunday to make sure everything's as it should be, and as i said i really don't have any experience of mixing for cinema. Unfortunately there's no budget or time at this point to get into a dub stage to check everything out, although i have been pushing for it.

Thanks in advance

[Whitecat]

Theatrical mixes aren't peak limited, I'm not really sure why you're being told that (unless they have 4ppm calibrated to 0dbFS? ) - Once you calibrate, you mix by ear, make sure it doesn't go over 0dbFS and you're laughing. The stuff that even approaches 0 though should be loud, loud stuff - explosions etc.

[danijel]

Originally Posted by joe945

Bascially what i've done, after reading up on here & the DUC forum, is calibrated my listening position (fireface 800 da straight to adam p22a's - with plenty of acoustic treatment in a small room) to 83dbc - slow on an SPL meter playing back pink noise @ -20dbfs

83 is probably too loud. Try playing some reference-quality movies off of DVDs (with a dialnorm-aware player, turn off DRC), set a good listening level, then turn the volume down by 4dB, and there's your mixing level.

Originally Posted by joe945

The people at the post house have asked me to ensure that peaks don't exceed 4PPM (UK), but since i'm working itb in dbfs i've no idea what this translates to..from what i can gather it's -18dbfs? Is that right? If so does that mean that i need to trim / set the limiter for the whole mix down to peak at -18dbfs?

My math is the same (4PPM = 0dBu = -18dBFS [EBU]), but then I don't really use PPM.... I'd call again and ask them to double-check, because limiting @-18dBFS makes no sense.

Originally Posted by joe945

I've also been asked to add 5 seconds of -18dbfs 1khz tone onto the start of the mix, presumably so they can calibrate the digibeta deck to the right level?

Right.

Originally Posted by joe945

The mix i've done so far, which is set to peak at -10dbfs has an average overall RMS of -30dbfs (no way of doing dialogue rms), does that sound about right or am i being a bit too conservative?

That depends on the film. John Wu films have much higher overall RMS than those of Andrei Tarkovsky, yet the dialog volume is consistent across

[DanDan]

I have researched this a lot.
PPM4= OVU= -18dBFs in EU = -20dBFs in US

I agree that 83 is probably too loud. Try -20=75.

I reckon you are very much in the pocket with your -10dBFs.
For music, I usually set an L2 brickwall at -6 and tickle it.
This ends up hitting PPM 7 fairly lively.

There is a software PPMulator. Very similar to the real thing and it makes these level calls quite easy.

Best Regards, DD
Sound Sound - Homepage

[joe945]

Thanks for the replies..it's very much appreciated!

I'll talk to them again tomorrow about the peak levels, -18dbfs makes no sense to me either.

danijel - i'll definately try that to see how the mix translates. I referenced quite a bit with commercial dvds when i was doing the dvd mix, mainly for dia levels & tone / eq ect.. & that seems to have gone ok. For the theatrical mix i've toned things down a bit from the dvd mix..hopefully that was the right way to go otherwise i'll not be getting much sleep this weekend

Just trying to understand the thinking re turning down by 4..would it be the case that i'd set a good / comfortable level for a -10dvd (that is generally right isn't it?), turn down by 4, then mix to 0dbfs peak. So basically my mix level will then be +10dbfs peak level from the dvd & 4 down from that on my monitor end, so that i'd be monitoring essentially +6 higher than for a dvd mix? which would naturally lend itself to a mix with more dynamic range? Or am i talking total crap?!

will also try -20 pink noise to 75 - see how that works.

it's a bloody minefield hey! think i'll open a beer or 2 & try to work this out tomorrow!

Will let you know how i get on anyway..thanks again

[danijel]

Originally Posted by joe945

Just trying to understand the thinking re turning down by 4..would it be the case that i'd set a good / comfortable level for a -10dvd (that is generally right isn't it?), turn down by 4, then mix to 0dbfs peak. So basically my mix level will then be +10dbfs peak level from the dvd & 4 down from that on my monitor end, so that i'd be monitoring essentially +6 higher than for a dvd mix? which would naturally lend itself to a mix with more dynamic range? Or am i talking total crap?!

Yes, you are

Don't think in peak levels. DVDs and theatrical printmasters don't have to be peak limited, DigiBETA peaks are usually @-10dBFS (even if it is not meant for TV, but theatrical presentation - your case). Whatever the max peak is, you should be, above all, concerned with calibrating properly, so that you get proper sound loudness (dialogue, above all).

When a DVD is encoded with dialnorm -27, that means that average spoken dialogue is around -27dBFS RMS, most generally speaking (it does not mean you should measure your dialogues RMS). This is also (again, a BIG 'IN GENERAL') true of theatrical mixes. When played in a DVD player, the player attenuates the mix by 4dB (if you read everything about DVD metadata and dialnorm, you will see why).

So, when you find a good listening level for reference DVDs, you have to duck your monitoring by 4dB to 'emulate' what DVD player does. This will be also the most compatible monitoring level for translation into theater.

This is just a practical explanation, because you are in a hurry, but to fully understand the matter, I advise you to read everything about dialnorm, levels & calibration one more time (all contained in the stickies here and at the DUC.)

Originally Posted by joe945

will also try -20 pink noise to 75 - see how that works.

OK, but how will you see if it works? You would have to mix something at that level, then go to a calibrated dub stage with your material and see how it translates, and if it doesn't, repeat the process a couple of times.



Good luck!

[dr.sound]

DO NOT MIX AT 75 SPL !!
If you don't know mix around 80. If you mix at 75 you'll rip everyones head off!
Since the Production company won't pay to playback your mix in a "dub stage" go with 80.
At least it will be in the ballpark!

[jahtao]

Was in your shoes not so long ago, managed to get 15min sound check the day before the screening at the theater. Decided to turn everything up by 6dB and that worked out perfectly on the day.

I've since, calibrated my monitoring chain. Ready for next time. Very soon, i think. Found the radioshack spl meter on eBay, the shop posted it to me instantly, calibration took 2mins. I strongly suggest you do this if you have time.

But getting a sound check is very reassuring, try for it.

Matt

[joe945]

Originally Posted by dr.sound

DO NOT MIX AT 75 SPL !!
If you don't know mix around 80. If you mix at 75 you'll rip everyones head off!
Since the Production company won't pay to playback your mix in a "dub stage" go with 80.
At least it will be in the ballpark!

Ok..now i'm really worrying. The LAST thing i want to do is to rip peoples heads off at the screening!! Which is why i've been mixing quite conservatively at 83db - although now i'm concerned that the dialogue might end up too quiet in places having done it that way.

So, just be to clear, the order of steps i need to take, as a general guideline & considering the time constraints, is that i need to calibrate monitors to 75 or 80db (not sure which now?) playing back the -20dbfs pink noise..set the output of the DAW to 0dbfs (no limter) & mix by ear again from there?

The mix i've already done for this was at 83, with the daw out set to -10dbfs whilst mixing..so i'm now presuming that was totally wrong? Oh crap.

Not sure i made this clear before but the person doing the digibeta layback is a actually a dubbing mixer with some experience of mixing for film, it doesn't look like they're set up for dolby at the place they're doing the layback, but i'm presuming that they'll be making sure that peak levels are right for the screening. I'm going to see if i can get in there when they do the layback & get to hear it back on their system as they've said they'll be having a listen to the mix.

I think i'm really going to need that luck danijel!!

jahtao - that's a bloody good idea..will see if i can sort something out

[DanDan]

Your levels are fined. Don't worry. Look into the detail another time. Get an SLM. Get PPMulator. But for now, your level as described, seems fine to me.
Enjoy your night.
DD
Sound Sound - Homepage

[joe945]

DanDan - you think it'll be alright?

I've got a digital spl meter i got from Maplin's & have just checked the calibration again.

What i did was play back the dolby -20 dbfs pink noise file & set the volume of each of the adam p22a's, one at a time, so that the spl meter read 80db. I then just played back some of the mix i've done, which is set to peak at -10dbfs, and at that level all sounds pretty good...the thing is i'm actually reasonably happy with this mix (for the first time!), so would be gutted if it didn't come across right in the cinema (which is a Vue btw).

The thing that's concerning me, and i know i'm a worrier, is that if this is going to end up at 0dbfs for the cinema playback, that it is going to rip people's heads off - i've just tried it at 0dbfs with speakers calibrated to 80db & it wasn't a pleasant experience!

Any more help or input i can get on this would be very much appreciated!

[DanDan]

Your level is fine. I guarantee it. Is there any way you can get into the screening room beforehand to do a soundcheck?
DD

[joe945]

thanks DanDan - yeah i'm going to make some calls this afternoon to see if i can sort something out. The only problem is the digibeta's being done monday afternoon & the screening's on wednesday evening, so i'd have to try & get in monday night or tuesday morning. But then if there were problems there's going to be very time to get another mix done (unless it's just an overall level thing) & then get back in to do another layback to digibeta..so it'd be much better just to make sure i'm calibrated right & re-do the mix before monday if needs be.

i'll call the post house again & have a chat with them about these levels, & try to find out if the mix would be bumped up to 0dbfs for the cinema playback..just to be sure.

cheers

[DanDan]

You really will have to stop worrying and be happy. No matter what way you look at this it is an overall level issue. The cinema can turn it up or down. You are happy with how it sounds. From what you said, by the numbers, it appears to be at least in the ballpark, or as I keep saying, most likely just right. If you can schedule a sound test, do, that would be real and real assuring. All of us feel insecure at the moment of delivery, when handing over. You just have to trust that you did the work, the research, and gave it your best shot. The worst thing to do would be to try completely new untested things at the last minute. Over the weekend, download the PPMulator demo. Burn a DVD and compare to commercial releases which have some similarity to your project.
DD

[dr.sound]

Here is the issue:
When you mix at any level in a room you make decisions based upon what you hear. For example you EQ dialog brighter or maybe adjust music to play a certain way.
Now you go into another room that is larger (the Theater) and you play it back and things change. That dialog that was coming out of a speaker in your small mix room that sat 5 feet from you is now 50 feet from you.

I suggested to mix at 80 spl.The Feature is NOT played back at digital "0". That would be 20 db louder. That is why we have 20 db of heardroom. NOBODY MIXES AT 0!!
After the screening post your experience here and let us all know how it went. That should get you into the ballpark. Now playback your mix in the Theater BEFORE the client or crowd arrives and adjust the volume up or down so that the dialog is easily heard. Also go to a loud area in the Feature and play that back.
After the screening post your experience here and let us all know how it went.

[joe945]

Thanks guys for all the help & advice..just to let you know i've stopped worrying and am a happy chap!!

Had a chat with the post house again this afternoon about everything & they were great. Seems i've done it all right after all! I've had another listen through at 80 & the mix comes across nicely still, so no worries there either. Sorry for doubting your advice!

I think the reason i got so concerned with levels is that i was told they'd have no control over volume in the cinema..so basically if it wasn't spot on on my side it'd be my balls on the line!

Anyway, i'm now going down to the layback session & we're having a viewing there afterwards..it'll be great to see how it translates on a different system & in a bigger room. I'm also taking a non-limited version so they can run it through some nice outboard to sweeten it up if needs be, so it's all good.

dr.sound - totally understand what you're saying about different monitoring levels affecting mixing decisions..i mixed this version very differently than the dvd mix i did first.

Will let you know how everything goes, i think it's going to work out just fine & i'm really looking forward to it