# Some Notes on Sound for Picture These Days



## fractile (Mar 15, 2009)

I've been studying a range of movies old and new for the qualities of the sound-track: dialog and music.
It seems to me that sound for movies is generally mixed for presentation in a commercial theater, with ~87dB sound-level and a very big array of speakers. All this adds up to adequate intelligibility.

More often these days, movies are displayed from a DVD in a home theater or more simply. This changes the dynamic range and frequency response. Unless the DVD release has been remixed or there is an alternate sound-track, intelligibility will suffer.

What I am proposing it seems is an approach similar to what has traditionally been done with commercial music releases, in that the mix will get through on all display/playback systems.

To get more specific, when the dynamic range is reduced, in an acoustically deficient space, the sibilance of the dialog can get lost. The ambient quality of background music is another story.

:clap:


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## Sandro Gomes (Jul 8, 2009)

Few years ago I made a mix for a first time independent movie director here in Brazil, after my mix was ready he sent it to a studio to print it in the film, at this time some smart dude at the studio told him that he would need to remix the whole thing _'cause it wouldn't sound good on youtube_. He was saying that a mix need to fit in every media. I would do another mix for youtube for him, but he liked the ideia of "one media fits all" and ruined the mix for the theater.

As far as I know, mixing for the theater and for home systems is not the same thing also, movie theaters have their own standarts on levels and acoustics, and a home systems is something complete unpredictable, so for the last you need to make a mix concerned on these things, speaker positions are rarely respected, room acoustics are praticaly inexistent, this way you have to compesate these possible problems on your mix, to make sure your audio can sound ok on every system.

I don't like it either, but that is how things are done, even for music, I hear a lot people saying that they test their mixes in all kind of environments, like, mini-systems, car systems, portable systems, ipods, etc. We don't want it to happen with our movies also, so I believe it is better to have a mix for the theater and a mix for DVD.


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## ngarjuna (Mar 29, 2010)

I definitely agree with Sandro Gomes, different mixes are required for different applications.

I realize I'm probably just "delicate" but I hate the dynamic range of films on home theaters today. I usually end up holding the remote the entire time so that I can turn up the dialog (which is usually inaudible when I get the average volume where I like it) and turn down the explosions/gunfights which, at that same average volume, are way over the top. In a movie theater, it totally works for me. In my living room I simply don't need or want that kind of dynamic range. Perhaps my biggest pet peeve are mixers (or maybe producers make this decision, I've done very little audio work for film or television) who make musical interludes as loud as explosions. I recently screened the new Sherlock Holmes film and every time there's a musical transition the volume got unbearably loud; sigh, turn it down and then wait for the next inaudible line to turn it back up. At least for an explosion I understand conceptually how that would have worked in the theater; but scene transition music? Does it really have to be 10+dB louder than a normal conversation? And forget about a movie with lots of whispering or if you're watching in environment with a fan or air conditioner.

I'm not a "squash everything" kind of engineer, I work on a fair amount of classical music and appreciate the importance of having a nice, wide dynamic range. I just think modern DVD releases have gone way too far with the concept for their context.


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## fractile (Mar 15, 2009)

Some good points made here. And with current and future disk capacities there is/will be room for several soundtracks. I think the simple volume of the space in a commercial theater allows for that broad dynamic range. Plus, acoustic treatment of the space allows this for a "home" theater.

One thing I didn't mention is that some surround receivers have a dynamic range adjustment. One form of this is dial-norm, D-Norm, dialog normalization. I had a Sony receiver that had a more general adjustment, but I traded that in for a Marantz SR8002 because the distortion in the Sony sound was about 10%. On the Marantz there is a "Night" setting. This type of adjustability in digital sound would make multiple sound tracks less of a requirement. Thanks for the feedback; this was something I wanted to aire.


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## maikol (Nov 7, 2008)

ngarjuna said:


> I definitely agree with Sandro Gomes, different mixes are required for different applications.
> 
> I realize I'm probably just "delicate" but I hate the dynamic range of films on home theaters today. I usually end up holding the remote the entire time so that I can turn up the dialog (which is usually inaudible when I get the average volume where I like it) and turn down the explosions/gunfights which, at that same average volume, are way over the top. In a movie theater, it totally works for me. In my living room I simply don't need or want that kind of dynamic range. Perhaps my biggest pet peeve are mixers (or maybe producers make this decision, I've done very little audio work for film or television) who make musical interludes as loud as explosions. I recently screened the new Sherlock Holmes film and every time there's a musical transition the volume got unbearably loud; sigh, turn it down and then wait for the next inaudible line to turn it back up. At least for an explosion I understand conceptually how that would have worked in the theater; but scene transition music? Does it really have to be 10+dB louder than a normal conversation? And forget about a movie with lots of whispering or if you're watching in environment with a fan or air conditioner.
> 
> I'm not a "squash everything" kind of engineer, I work on a fair amount of classical music and appreciate the importance of having a nice, wide dynamic range. I just think modern DVD releases have gone way too far with the concept for their context.


I get your points, but this sounds pretty surprising to me, as I've often had pretty good impressions on movie soundtracks listened on DVD.

The mix in 5.1 is often the same as the theatre mix, but the stereo mixdown is often more compressed, as it is often played back on TV speakers.

But wait, are you sure you are listening to the stereo downmix?

Because is you listen to the 5.1 mix on a stereo speaker set, you'd only get the L and R channels, while pretty much all the dialogs are in the center channel.

I guess you're not doing this, this is just to be sure! :T


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## ngarjuna (Mar 29, 2010)

Mostly multi-channel mixes, I have a 5.1 setup in my living room. But you've given me an idea: I should boost the center channel unnaturally, that probably will help a bit.


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## maikol (Nov 7, 2008)

Yep that should help!

Maybe it is too low?

BTW, have you tried to measure each L C and R channel with REW?

Maybe there is an acoustic problem in your living room, that would affect specially the center channel?

Or maybe it is just not as loud as L and R ?

M.


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## fractile (Mar 15, 2009)

I became aware of the 5.1 <-> stereo situation; in my studio build/transition I hooked up only a stereo pair of speakers without the center or surround speakers. Selecting "Stereo" on the receiver fixed that.

On raising the sound level of the center speaker, notice that many "center" speakers have two woofer/mids. My impression is that this glues the sound center screen at the picture, better than a simple stereo pair; especially as the screen grows in size.

I've done some testing in my small room. With the center speaker below the screen the sound sounded below the screen. With the speaker above the screen pointed down it sounded like it came from the picture. Your results may vary.

At any rate, I recommend a modular/prototype and experimental approach to arranging the speakers and setting levels. There are good rules of thumb recommended as the standard, but I each room is unique

I broke this window cursor so will send now


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## Sir Terrence (Jun 8, 2006)

fractile said:


> I've been studying a range of movies old and new for the qualities of the sound-track: dialog and music.
> It seems to me that sound for movies is generally mixed for presentation in a commercial theater, with ~87dB sound-level and a very big array of speakers. All this adds up to adequate intelligibility.


That would be 85db instead of 87db. What really makes for adequate intelligibility is the acoustics of the theater itself. 



> More often these days, movies are displayed from a DVD in a home theater or more simply. This changes the dynamic range and frequency response. Unless the DVD release has been remixed or there is an alternate sound-track, intelligibility will suffer.


Actually its not dialog intelligibility that suffers, but extreme dynamic range becomes a problem, and the frequency response of the track becomes more heavily skewed towards the high end because we are sitting much closer to the speakers than we do in the theater. 



> What I am proposing it seems is an approach similar to what has traditionally been done with commercial music releases, in that the mix will get through on all display/playback systems.


Unlike music, there are certain ways a sound track can be played back in the field. Either you get a full 5.1, or a stereo mix down. There is no way to optimize a mix for a 3.1, 4.1, 2.1 system, because you just cannot optimize for all of the different approaches folks use for playback. We just keep it simple - give the best 5.1 mix than can be successfully folded down without a huge amount of problems. I usually ask my clients to allow me to create a separate stereo mix, rather than trying to optimize a folded down mix. 



> To get more specific, when the dynamic range is reduced, in an acoustically deficient space, the sibilance of the dialog can get lost. The ambient quality of background music is another story.
> 
> :clap:


It is actually the opposite. When the dynamic range of a sound track designed for a much larger room is reduced, what you get is better dialog clarity(you don't want excessive sibilance), and a overall mix that is easier on the ears.


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