Stereo sound vs dolby for theatrical release

M

Michael Chen

Member
Hi there,

Need some advice on the sound mixing for my first feature.
We are making our first feature to be released in the theatres end of the year.
Since it's an independent feature, we do not have the budget to go for dolby.

Few days ago, I've just transferred our stereo sound to 35mm and tested them in a theatre, and for some reason , it is not as good as it sounds on our sound engineer home studio. Somehow, it now lacks the impact that was heard before transferring.
More over, only the front 2 speakers in the theatres has sound, the rest of the speakers are mute. I remember watching movies on stereo in the theatres, and I didn't notice that there are no sounds from other speakers, maybe I didn't take note?

The volume of our soundtrack has gone down as well. The volume needs to be way louder to have an impact.
The film transfer house has adviced us to go for dolby as they mention that stereo analogue will have a degration in quality once transferred since it's not in digital. And they won't be able to boost up the volume.

Do we really have to go for dolby as adviced by the transfer house? we spent a lot of effort in making this film, and in the last stage, our only dissatisfaction is with the sound.

I am not sure what went wrong.. any advice for me?
 
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your sound engineer should be able to answer this for you...

at the very least the people who did the 35mm transfer should be able to answer it for you...

if your soundtrack is just stereo then yes you will hear it in two speakers, the left and the right.

in my home studio where i do editing and other post things i have a 5.1 surround system.

from my editing workstation i am in the center of the room and in front of me is a lower area with a leather couch for people to sit when i'm doing final edits on their projects.

the room and my workstation is all centered around the acoustics, from my computer i feed the sound to the receiver etc. directly from the computer and i have to go in and pick what track is to come out the center channel and what is going to come out the left front and right front and then the left and right rear/surround speakers and then the same thing for the subwoofer/low frequency

go back to the people you have had working on your movie and have them explain to you what it will take to get your movie to sound like what people expect to hear in the theater.

if your movie sounds like it has all the channels/speakers working at the sound persons place then it sound like he has done the work already and that he and you and your people who are taking the movie and putting it into the 35 mm / theater format all need to talk to each other.

matthew
 
This is really an issue that has to be worked out in your final mix. After you decide what the final format is the engineer needs to mix it to get levels right for your chosen format (one of the reasons they make the big bucks). I have a decent studio set-up and mix for TV all the time but if the project is going to 35mm I pass the final mix onto one of the two main post houses in town. A person simply can't mix for theatrical release in anything but a perfect studio.

You are going to want a minimum of Dolby if you are going with a stereo optical track. The analog noise will completely ruin all your hard work. Dolby Stereo is actually reasonably cheap to do.

To get this done right make hire a post house that regularly exports for film opticals. These guys are up on the best solutions for your soundtrack and know how to get the finished tracks right (simple things like screwing up the pull down at the optical printing happen all the time).

Not to dimishmish the expertise in here but you honestly would want to post up further concerns on a board that is post specific. Guys that do this stuff full-time will have far more insight. There are a number of Pro-Tools and Nuendo boards out there. Since switching to Nuendo I go here all the time: http://www.nuendo-post.com/index.php (although the protools boards have the more of the oldtimers for these non-software specific questions).

Good luck
 
Thanks for the advice. Dolby Stereo sounds like a good option, but the transfer house that I go to only does Dolby Digital 5.1 and my budget does not allow me to do that.
Right now, they are transferring my final mix straight to the optical stereo analogue.
Any idea how much dolby stereo may cost for a feature film? and any studio recommendation?
 
Dolby suround (Optical track 4.1 matrixed surround) is about $1,200 for festival only and more for theatrical release. Dolby Digital is around $12,000 for theatrical. You can only do a digital mix in a Dolby approved mix stage and Dolby has to send there guy out with the Dolby digital recorder.

You should have done a bit more research before the mix. When mixing for optical you NEED to mix to the transfer houses spec. You or they have to encode the mix with Dolby SR noise reduction.

If your mix was only playing out of the LR speakers then either there is something drastically wrong with your mix or more likely it was not played back through the matrix (Dolby cinema processor). The level being off could be the mix, could be the transfer or could be the theatre.
Did you mix in a calibrated room? If not slap your wrist. If you did then it could be that you were in a studio and not a mix stage, things sound different when you go to the big room. The transfer folks could have screwed up, happens all the time, or you could have mixed out of spec and they HAD to turn down the mix to keep the optical from distorting. You were mixing in a calibrated room and mixing to a standard reference level and watching the peaks to keep them within the optical track limits right... If not slap your wrist then go slap you supervisor and mixer's wrists.

Lastly if all else was perfect the theatre has a volume control on the cinema processor and it often gets turned down because of loud trailers. It should be set to 7.

So go back to the theatre have them play your mix through the Cinema Processor with the level at 7 and see what it sounds like. If nobody SR encoded the tracks it will sound like **** and you can go slap every one again.

The matrix (Dolby C. P.) will take take a stereo mix and all mono parts will come out of the center speaker, left will come out of the left and right will, can you guess... Random stuff that is out of phase will creep into the surrounds and bass will go to the sub.

Usually hardly anything will come out of the surrounds but sometimes music and really phasy FX will get sent there. If you didn't monitor through a CP then you wont know what will end up in the surrounds till you hear it in a theatre. Usually it's not a big problem. If it is start slapping people again.

If you have to go to a stage and remix, while your there paying $350+ an hour keep repeating "there is a reason to hire folks who actually know how to do what you need done".

I don't mean to be harsh but I just spent way too much time with a director/ producer who spent over $100K on a very short 35mm and had not done ANY research on how sound got on a 35mm print, and this was essentially a music video. THey had no idea of the process or the costs or the limitations or the time it would take. And of course they had budgeted no money time etc for any of it. It's like buying an expensive car with out knowing how to drive.

Hopefully it was a screw up at the theatre and everybody did a great job. If not go get some balm for those wrists, they are probably smarting by now.
 
Noiz2 said:
Dolby suround (Optical track 4.1 matrixed surround) is about $1,200 for festival only and more for theatrical release.
Click to expand...

$@%$!#$*% I KNEW IT!!! Those damn Dolby nazis. These guys are very protective of their monopoly and price structure. I often suspected they have different prices for different clients.


:furious3: :furious3:
 
You are right, but it's not fixed. You can with the right connections get a better deal. I had pretty good connections and I couldn't so I called SRS. The make a matrix compatible box that they shipped for free and the license cost was putting there logo on the film (something Dolby requires also). It worked fine. You do have to separately do a SR encoding but that does not require a license. By the way Pro Logic uses the same steering logic so that could be an option, but you can't use the Dolby logo.
 
Noiz2 thanks for the feedback.
We are transferring the sound on stereo only..We did a second test and it sounds alright when the theatre boost up the volume. But it only comes out from the front speaker.

According to the transfer house, only the front speakers will work for a stereo mix. If we'd like to go for surround sound, they can do it with dolby digital, which we do not have the budget for it. They only gave us 2 options.

I'd just like to double check here to see if they are accurate with the information, since if we can just take up another cost effective way to make the rest of the speakers in the cinemas work, we'd definitely consider it.

Thanks for your help so far.
 
Your on 35mm, the transfer house cannot give you a Dolby Digital track. Only Dolby encodes Dolby Digital. If they are saying anything else there is either a miscommunication or or they are BSing you.

They maybe thinking AC3 DVD encoding, that is not a 35mm film format.

I'm not sure where you are so it's hard to recommend someone but you should have a sound person you can talk to preferably local who can asses what you have what your trying to get and how to get there. Forums are great for general knowledge but you have some very specific info you need and this is not the best way to get it.

If you didn't mix in surround you won't get much out of the surrounds (hopefully). The format doesn't matter much. If your mix is stereo and you went straight to Dolby Digital (you can't, but if you could) you would have a stereo mix with sound ONLY coming from the front L & R speakers. Dolby Digital is discrete, it's a one to one match of tracks to speakers.

Optical 35mm sound is two tracks. They can be recorded as mono Stereo or "matrixed". Dolby Stereo (also called Dolby Surround) is a matrixed sound track. You mix to four tracks and the encoder "matrixes" the tracks in to two tracks. These are refered to as LtRt (Left Total & Right Total). When played back through a decoder box you get 4.1 tracks out (.1 is how the sub woofer is refered to ie 5.1 is five tracks and a sub). THe sub gets any signal that is below X and everything else goes out to the main speakers. The speakers are Left, Center, Right and mono Suround.

The idea of the matrix is that it is stereo and mono compatible. So a matrixed mix can play back on any system. By the same token any stereo mix can play back through the decoder and it will "decode" the mix. For a streight stereo mix this means that Left will be on the Left and Right will be on the Right. Anything that sounded centered in the stereo mix (what's called a phantom center) will be in the center speaker. Somethings will show up in the Surrounds, not much usually. There is a formula for the encode decode and if your stereo mix has a lot of phasey stuff in it some of that will end up in the surround because it accidentally matched the formula and got sent there. This (refered to as "magic surround") happens mostly to music.

If you have a "stereo" optical 35mm print and you are only getting sound out of the center speaker you are in mono. Either the theatre, the transfer or your mix has ended up in mono and you need to find out which and get it fixed. If your only getting the L & R speakers and no center. Either the theatre center speaker is not working or your mix is not going through the decoder. If your getting all three front speakers and hardly anything out of the surrounds that's because you didn't mix in surround and you didn't encode that surround mix so you are getting what you are supposed to and your lucky that something distracting is not coming through the Surrounds.

Get a local who knows what they are talking about to look at your project. Depending on where you are I may be able to recommend someone. And this should not cost a lot. If they are not willing to talk to you about the film with out charging you, you have the wrong person. All of us do a fair amount of free counseling. Not because were such great people but if I help you out now maybe I get the next job with a budget or a lead to one etc. You don't need a ton of someone's time you just need a little trouble shooting and some advice.
 
Hey Scott,

These are some of the best descriptions I've seen about the Dolby process - maybe we should extract them and stickie them.

Quick question - does THX change any of this process or is strictly a certification? For example, the Century Theaters in Milpitas (Great Mall) are all THX capable - do you have to do anything different in your mix to take advantage of THX or is it really just Dolby?

Thanks!

Phil
 
Thanks again for the feedback. It's much clearer now. So I believe we did ok for a stereo mix.

We are doing the transfer in Thailand. So anywhere close that can provide us additional options will be great.

Yes, forum like this is good, it's where we can get a second opinion. I've got a lot of beneficial feedbacks from online forum, which has help tremendously on most of my projects.
 
THX is kind of a wank but at it's best it tries to set standards for play back quality. There is some kind of connection to Dolby but unless Dolby bought them there isn't an official one. Also Dolby doesn't certify theatres. THX certification means you followed there guide line in construction and I think they do some checking of the installation. There credibility is a bit tarnished because they hand out their name like the Good Housekeeping Seal. You can buy speakers that are THX certified. I have no idea what that means. It certainly says nothing about how well those speakers will sound in your livingroom, after they get placed badly and phase inverted... Plus THX has or had some strange specs based on pretty bad science. For instance on mix there is a big emphasis placed on the volume of the space. In theory if you had a five seat theatre with the speakers on your lap but the ceiling was high enough you qualified. This may have changed? Also the THX box that was required at one time had a bunch of switches that added noise to the sound system. These various hisses were supposed to mask out outside noise. The TH is for Tomlinson Holman, the guy who worked for Lucas to make sure the theatres that showed StarWars 2 (5) sounded better than the mostly really bad sound that drove GL mad with SW original release.
 
That indeed is out of my area and unfortunately I really don't know anyone close.

But maybe some one else on here does. The other place to ask is #1 RAMPS, it's a news group but you can get to them through Google groups, and the Post Production section of the DUC (Digidesign Users Conference) on the Digi site.

Sory I can't be of more help.
SK


Michael Chen said:
Thanks again for the feedback. It's much clearer now. So I believe we did ok for a stereo mix.

We are doing the transfer in Thailand. So anywhere close that can provide us additional options will be great.

Yes, forum like this is good, it's where we can get a second opinion. I've got a lot of beneficial feedbacks from online forum, which has help tremendously on most of my projects.
Click to expand...
 
Hi Noiz2,
Just went through your previous post, I have one last question.
Let's say if we mix in surround, but we are not doing the dolby digital, will it still play in surround when transferred to optical 35mm?

I am receiving 2 feedbacks at the moment. One side is saying without dolby, the theatres will not detect surround sound, and another side saying as long as your final mix is in surround, it will play back in surround when transferred to optical 35mm even without dolby.

Thanks again.
 
Mix in surround. I'm assuming you mean discrete 6 track. That is in the mix your print master is in a format where L,C,R,Ls,Rs & Lfe are on diferent tracks on the dubber.
That recording can't directly be put on to a 35mm print. Optical only has two tracks.

If you also create a matrixed mix, that matrixed mix (LtRt) will decode through the Dolby Cinema Processor and come out in 4.1 surround. Only Dolby can encode the Dolby Digital 5.1 track and it doesn't go on the optical track. It sits between the frames in what looks like a series of bar codes. To do Dolby Digital on 35mm film Dolby has to come out with there magic boxes to your final mix. They record on to there own recorder and take it back to the Dolby lab where they generate the specialized track and that goes with your analog sound track and the whole thing gets printed to an optical sound negative that gets exposed on to your final release print. The Dolby track may be it's own negative or it might be part of an over all sound negative, I'm not sure which, but either way you have a sound negative and a picture negative. For very small numbers of prints I have heard that there is a way to burn the analog track on to a print with a laser and save the cost of the audio negative but I'm 99.99% sure that would not work for DD and who's going to pop for DD and only release 5-10 copies?

You can also go for SDDS instead of Dolby D but again it's a proprietary format that there are no workarounds for. On 35mm Dolby Stereo (4.1 surround) is the only format that you can find alternatives for.

For video it's the wild west. There are a slew of diferent semi compatible formats out there and all of them can be encoded with out help from the Big boys.
 
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