Do I need Dolby to open a small dubbing stage (only for DCP)?

[lynx lynx]

Hi! I would like to open a small dubbing 5.1. cinema stage to mix for DCP format, 6 discrete channels final (printmaster?). I wonder if I need Dolby for this at all, for means of checking, calibrating and approving the room. Is it a part of ANY regulation for film sound creation or it is just "virtual" monopoly which Dolby is continuing to lead due to the previously standardized matrixed coding and decoding of SR, Dolby Digital etc?

What about X-curve, Dolby processors (DA20, CP500, CP650, CP750) and "big" JBL speaker systems? Is it a part of ANY regulation for 6CH discrete DCP audio, ANYWHERE in the world? I know about subjective difference between mixing on such systems and mid field monitoring but what is the exact technical (all cinema systems should be frequency flat and have same SPL) difference between (for example) mid-field Genelec monitoring and JBL cinema speakers with X-curve. Is it only about the size of the room, could you theoretically place big Genelec speakers in big room and do mixing without X-Curve or X Curve is just the protection from HF for audience in the first rows, disregarding the model of the speaker.

Digital age has come for sure, and I feel Dolby knows that with discrete channels, unfortunately we will not need them so much as before, and mixing on big dubbing stages with SSL and NEVE does cetanly not make sense for 1 or 2 week low budget mixes, compared to work on Pro Tools! I just need "correct" monitoring and room, nothing more, nothing less! Or....????. Is Dolby the only company which will give me guidelines and certification of the room, and does someone know about their price for this. Hope someone shares these thoughts and has some theoretical and practical information about all these things.

Martin
Production sound mixer, Sound Designer, post mixer
Croatia, Eastern Europe

[lynx lynx]

Is this all some kind of secret or it's just too obvious and it's been talked about somewhere else, please redirect me or give me any info. I am a sound artist not businessmen and I just want to get my "canvas" right. Tnx for any info or help

[KMcK]

Try this forum: Gearslutz - Post Production forum!

[paulo m]

If you´re just working for DCP, you don´t need any type of Dolby licence or certification. Like you´ve said, only when you´re mixing for Dolby Digital or analogue matrixed Dolby.

However, it doesn´t mean that you can forget proper acoustics and monitoring to assure that your mixes translate well in a cinema venue. Given Dolby´s knowledge or in fact any other companies or studio designers that have experience in building and calibrating mixing rooms that deliver cinema mixes, in my opinion it´s worth employing the services of such a company or studio designer if you´re not sure about the full specs in terms of monitoring, room dimensions, acoustics etc.

A couple of years ago, at a company where I was working, we setup a room according to the Dolby specs, including a CP650, got the Dolby certification for commercials and trailers, but ended up never doing anything in Dolby, just DCP.

But the fact that the room was properly calibrated helped us to stay assured that the mixes would translate better, even if all we´re delivering was discrete mono files for the DCP authoring and not for inclusion on an optical disc. We even had a DMU for a while, but basically end up using it just for the metering and Leq calculation. We got our room certified at a technology change point in terms of delivery for cinema, so the DMU got returned to Dolby, but the CP650 stood in the room as the calibration for the room´s curve was stored in it.

The room didn´t have any JBL´s or other typical cinema speakers. In fact it had 5 B&W 802 D and a Genelec 7071 A sub. It sounded great, even the Dolby personnel were excited about it. All we were asked was to add a pair of smaller speakers on the rear to enhance the difusion of the rear channels. This was acomplished with a pair of B&W CT 7.4.

Also important and not usual, the speaker layout was the ITU one. You can check some pics here:

http://www.ep-producoes.pt/artigo.as...QqI9a0Vgi%2FPC

So that´s my personnal practical experience. Hope it helps.

[jeremiahmoore]

It's about your clients.

Dolby's requirements are sensible. If you can, in my opinion you should plan to meet or exceed their spec. Get the certification when and if convenient, or when it suits you. (I've no idea how this works in your locale; here in San Francisco, Dolby is down the street, so it's not hard for them to come by.)

As I see it, the clients and the projects are the main drivers for this.

For instance: Be ready to get certified, then if you land a Dolby film, you get certified. Whatever suits your marketing plan.

-jeremiah

[vudoo]

We added a DCP authoring suite 6 months ago and as far as audio for DCP is concerned, the DCI specs let you author Digital Cinema Package containing multi surround mixes @ 24 bits and all the way up to 192 kHz.

With such specs, there's really no need for Dolby unless you're going for their new Atmos format.

[lynx lynx]

Tnx a lot Kmck, Paolo (B&W system seems fantastic!), Jeremiahmoore and voodoo! It all seems like common sense, but there is not a single person in Croatia who knows about this stuff and having Dolby down the road seems like a joke to me For now, I shell contact acoustical engineers from the Faculty of electronics in Croatia (they made sound studios for national TV, (BBC like)), and discuss about dubbing stage requirements with all this info... I know how it should sound and they do the mathematics and building.

However, if I go for bigger room, can I hire Dolby to do the testing and calibration even though I don't need their equipment? Do they do this and how much would it cost in USA?

I suppose not, as the processor is used also for X-curve adjustment as well (this is the only thing I need it for) So, would they do the calibration and testing if I buy some second hand Dolby processor from ebay for example (CP 500, CP 650)???

My last thought and idea about low-budget DCP cinema mixing is: Is it possible to hire a normal commercial movie theater for some nights or mornings and connect Pro Tools outputs to 6-CH analog input of CP650 (I know it is unbalanced 300mV input), place a Pro Tools Mac in the middle of the cinema and just mix!!! I realized that when renting a dubbing stage you actually need only monitoring and room (I don't need big SSL and NEVE) and every cinema has a good one (especially the new ones). This may seem like improvisation but does anybody know why it should not be worth trying it?

[Frank Kruse]

Originally Posted by lynx lynx

w much would it cost in USA?

I suppose not, as the processor is used also for X-curve adjustment as well

BTW: The infamous "x-curve" is not a Dolby thing, it's an international ISO (2969 ) standard for cinemas.

Frank.

[minister]

As others have said, you don't need Dolby to do DCP. Dolby would come out out tune the room with EQ. They don't get into acoustic treatments, sound isolation, etc. If you have never tuned a room to the X-Curve, then I suggest you bring in someone who has. It can be tricky.

You will also need to figure out all the equipment you will need to properly outfit the room so you can simulate Cinema playback. Again, if you have not done this, get some people involved who have.

Contacting the Faculty at the University may be a good idea, but building a Dub Stage is different than building a small control room and live room for producing music. I suggest talking to some people who have actually built Dub Stages because the needs and layout are different.

Originally Posted by lynx lynx

I know about subjective difference between mixing on such systems and mid field monitoring but what is the exact technical (all cinema systems should be frequency flat and have same SPL) difference between (for example) mid-field Genelec monitoring and JBL cinema speakers with X-curve. Is it only about the size of the room, could you theoretically place big Genelec speakers in big room and do mixing without X-Curve or X Curve is just the protection from HF for audience in the first rows, disregarding the model of the speaker.

mid-field Genelecs may not have enough power to comfortably play -20dBFS RMS PINK @85dBC, and cleanly represent 105 SPL for the loudest explosions in your proposed room. I know you said small, but how small? Typical control room ok, but for a Dub Stage mid-fields are not enough speaker.

The X-Curve is not for protecting HF for the audience in the first rows. There are a lot of misconceptions about the Curve. It's not that you X-Curve JBL's and not Genelecs, as you imply. It has to do with room size, room response, and speakers as a system. They all work together and achieving the X-Curve is done by seeing how the whole room reacts (as measured at the mix position) to PINK and adjusting from there. You should do the X-Curve if you want the work to translate to theaters or larger Dub Stages. It doesn't make everything sound duller; it controls HF buildup in larger rooms and tends the response of the larger speakers to that of a mid or nearfield closer to the mix position. Plus, it helps in getting mixes translate from one thater to another. It is not perfect, but nothing is.

Again, you don't need Dolby to set up a room for X-Curve, but their Engineers are quite good at it, and I would trust them. I wouldn't do it myself; I would pay the money to have an experienced Dolby Engineer implement it. Or pay the money to someone who has good experience in doing this.

[lynx lynx]

Tnx a lot people, you are really wonderful! So much practical and real life advices and info, finally I feel I'm not alone in all this, and I can see that Dolby isn't only about money but they also do good for film sound all the time. I shall contact them and see how much would they charge. Do they do small room calibration as well??? Does anybody know any other company or person close to Croatia (Eastern Europe) who does building and consulting for dub stages.

In the meanwhile...what about renting normal commercial movie theater (not dub stage) for few nights and connecting Pro Tools there to CP650, is this idea too silly for some reason or what?