Postproduction basics

[High1ander]

Well that is another factor that works it's way in. How high is the bar for what you are doing?

On somethings the bar is pretty low and that is the nature of the beast. Doing a full sound post on a local late night used car spot is probably a waste and they are not going to pay for it and probably won't notice.

Most of the ads I did were national spots. We only really did the FX work, the final mix was done at a separate facility. For FX alone we had a two to three man crew for a couple of weeks to a month for a 30 sec. spot. Now usually we were working on a package with cut downs so the shorter versions took a LOT less time and usually we could cover field recordings for the package in a more efficient way. But still you are looking at around 200 - 400 man hours VS your 1/2 to 1 man hour. Actually it's farther off than that since I'm not counting the mix or VO work (usually).

So who is the model to follow? Well as keeps coming up "it depends". We also did a huge stack of bumpers and lower thirds for a network rollout and did 83 in two weeks. They were all animated and most were very FX heavy.

If your job is to knock them out quick and dirty then the big post is not even an option.
If you are doing a feature or a short you want to get into serious festivals etc. then you NEED to spend some time polishing the sound.

The bar varies on project and time limitations. The TV-spots I worked on I get clean VO from somewhere else, I get trailer sounds, or music, game sounds, etc. in various quality (sometimes I get trailers with mixed audio and music, and sometimes I am really lucky and get music, vfx, ambience and dialogue on seperate tracks). The key for me on most of the work then is just to make sure the VO is always easily heard, and that whenever there is a pause for "in game play, movie shot" etc. then I make sure that is clear and high enough. But the key here is more or less if it doesn't sound weird/bad, and the VO is clear, then it is more or less all good. Now, if I had to deal with various dialogue sources from different places and microphones then it would take much much longer. But I don't have to worry about matching reverb, warm/cold, etc. at least on the current projects I have had to deliver. But as you say, when doing short films, docus (I've worked as an editor on a docu for over 18 months once) then sound is much, much, much more of a pain in the ass because then you never have the budget for great location sound or expertise to get good sound, and then you basically have to sit and "fix it in post". Whereas on VO work for commercials, etc. then you have a sound proof room, expensive microphone, etc.

I always use a limiter (varies from -3 to -9db), and sometimes a compressor for the VO, but it is minimal, like 3-6 db. I usually make sure to get the levels somewhat right with the volume correction, then run around with the pen-tool to increase or lower where is needed. Fade in and out into every clip to avoid pops/clicks, not have any dead silence, etc... Basically its like making sure there are no black frames in video, or weirdly overexposed stuff, etc. Simple stuff to check for and usually fix, but makes a hell of a difference in terms of quality. Nothing screams amateur and cheap more than weird stuff going for no good reason, i.e. click sounds, pop sounds and levels jumping all over the floor. Fix that and you will at least not annoy the audience. I mean, if I see something horrible shot on TV, video wise, it will not hurt my eyes physically, but bad sound will if it is too loud or jumps back and forth, therefore I kinda find it the most important thing to do is not to screw over the audience with sounds that will hurt them.

 

[Jema]

Anyway you guys are saying that using a compressor isn't a must? I thought that this was like setting the contrast (black and white level) in the pictures. You know: so you don't have muddy blacks and whites and that you have a healthy amount of midtones. Is there such a thing to be done in post-audio? If you can relate to what I'm thinking...

Compressors are definitely not a must-have, but it depends on how and on what you work. A compressor is like automatic automation of levels with fixed values. Most prefer to adjust the levels manually, thus a compressor might not be necessary.

Volume envelopes means that you are basically using key frames to normalize the tracks, right?

Normalization is a completely different thing, but volume envelopes are normally called automation and is more or less like key frames. So yes.

So you use compression to get the RMS of a track up, if it's already good then no need?

Compression is an easy way to raise the levels when using more gain would get you above the allowable limit - it does this by lowering the peaks and thereby decreasing the dynamics of the signal, so the whole signal can then be raised.

Ok. So if you remove the noise from the let's say talking heads, do you then still put the room tone in between the cuts? If the room tone is only comprised of noise. Or is this not a likely scenario?

Yes, you generally put room tone in the missing spots where noise was removed. The auditory system is very sensitive to static sounds, like room tone, that suddenly disappears.

Can you explain this a bit more? Cameraguy here who knows little about sound, but wants to learn more, and one thing that I've noticed is that big shows NEVER stop to record room tone. Why is that? What are they doing in post that they can get away without it? I'm sure whatever it is, it's expensive, but I always forget to ask the sound department when I'm on set because I'm too busy.

There's a bit of a debate as to wether or not room tone is actually valuable. Some always do it, some doesn't. The reasoning behind those who doesn't is that room tone recorded separately never sounds quite like it did during takes, and is therefore of little use. You can generally find silent parts during the same take you need it for, that fits better. The need for separate room tone increases when the backgrounds change during a scene, or when there's very little pauses.

through the interview. You know, when they moved a muscle the chairs produced a noise, and the sound guy, well, he did nothing. This has to go out, any idea how to? There's probably lots of topic on the net about cleaning audio right?

If it's not at the same time as the talking, then simply replace it with room tone. If at the same time, then it would depend on the type of sound it made. If it's klicks, then it might be possible to remove, otherwise it would be hard (this is not an area I know very much in though, so search the web).

Nothing screams amateur and cheap more than weird stuff going for no good reason, i.e. click sounds, pop sounds and levels jumping all over the floor. Fix that and you will at least not annoy the audience. I mean, if I see something horrible shot on TV, video wise, it will not hurt my eyes physically, but bad sound will if it is too loud or jumps back and forth, therefore I kinda find it the most important thing to do is not to screw over the audience with sounds that will hurt them.

As a person with fragile ears, I deeply thank you!

 

[KINOKS]

Compressors are definitely not a must-have, but it depends on how and on what you work. A compressor is like automatic automation of levels with fixed values. Most prefer to adjust the levels manually, thus a compressor might not be necessary.

Normalization is a completely different thing, but volume envelopes are normally called automation and is more or less like key frames. So yes.

Compression is an easy way to raise the levels when using more gain would get you above the allowable limit - it does this by lowering the peaks and thereby decreasing the dynamics of the signal, so the whole signal can then be raised.

Oh, I see. So a compressor is generally used to cut down the peaks and that's it. But is there such a thing in audio world as
having a full "rich" sound. As it is in video... Or are you much more determined by what was shot?

 

[Jema]

But is there such a thing in audio world as having a full "rich" sound. As it is in video... Or are you much more determined by what was shot?

I'm not very good with video, but light and colors can loosely be compared to frequencies. We often talk about sound as being "dark" or bright" for instance. A full sound might translate into something that utilizes a lot of the audible spectrum.

 

[High1ander]

Oh, I see. So a compressor is generally used to cut down the peaks and that's it. But is there such a thing in audio world as
having a full "rich" sound. As it is in video... Or are you much more determined by what was shot?

Not really, the compressor is like on video when you make the dark shadows more grey and you make the bright highlights more grey too, you minimize the difference between high and low. A limiter is more what you are talking about which is something that cuts of high sounds that peak. I use the compressor to make sure that for example a VO is even in levels, but you got to make sure you don't compress too much, then stuff will sound flat (which it basically will be since there is no difference between low sound and loud sound).

Rich sound usually is high dynamic range (which is the opposite to what a compressor do, it lowers dynamic range). But remember that is just the dynamic range for that specific clip or track, you can still have a high dynamic range "scene" due to all the other elements.

If you have a guy doing a monologue where he screams for two seconds and then speaks, to then scream again to finish up with some whispering, then you want to have high dynamic range. If that is too compressed you won't tell a difference in audio levels between screaming and whispering, which would make the perfomance less powerful... However if you have guy giving a speech where everything is supposed to be the same level, but the guy keeps moving around a microphone (like a speaker on a convention) then you probably want to make it as even as possible with a compressor.

 

[KINOKS]

Okey I get it! So for giving the audio signal a wide "tonality" you have to play with it's frequencies with an EQ, is that right? You "open" up some certain frequencies to make the signal more broad and defined? But don't you risk of changing the speakers voice by doing this?

 

[Noiz2]

So you use compression to get the RMS of a track up, if it's already good then no need?

Not quite. I will sometimes use it on stuff aimed at TV to make it punch through more. It does effectivly up the RMS but it's a perceptual call, I'm not looking at numbers.

Yes, I kinda mixed this two up So basically you get a tone and you lay it under the voice. This is then an added tone to the original track right? But doesn't this just end up giving more unwanted noise to the track?

"noise" is unwanted sound. I'm only putting in sounds I want. And no I don't "get a tone" and lay it under the dialog. Building background tracks can be quite complicated. This is more of an issue with narative films than documentaries, though both can be complicated.

It would be helpful for you to cruse this stickie
http://www.dvxuser.com/V6/showthread.php?174562-Compilation-of-Post-Audio-Information
especially the "how to make your film sound like it had a budget.

The BG's are what create the "world" the film takes place in.
You shoot your talking heads. Where are they? In a city? in a cabin in the woods? Close to a forest fire? Your shooting them so the world is created by the sound around them. Even if you have an establishing shot that "world" goes away the minute you cut unless you continue the sound of the world.

Even in a totaly dry interview if you see a clock ticking you should probably hear it.

Many no budget films are just "dead" because nobody created the "world" of the film. You can "show" the world with CG but it a cool graphic till you can hear it also.

Oh, okey. By ressolution you mean 1 frame or 48kHz? ressolution

NO, I mean NLE's work in single frame increments and that is WAY too corse for sound work.

Ok. So if you remove the noise from the let's say talking heads, do you then still put the room tone in between the cuts? If the room tone is only comprised of noise. Or is this not a likely scenario?

Mostly answered above. A big film will fill everything out so the dialog sounds like one smooth take. I don't do that on low budget films because I'm not going to play the dialog on it's own for the director so the BG's are what sit's behind the dialog. In a big film most of the RT is going to be mixed out or WAY down in the mix anyway. You still need it in a number of places, like where you slice out an unwanted sound in the middle of a line. But it usually sounds better to just steal some silence from nearby.

 

[Noiz2]

Yes, I okey. I know this stuff, well, mostly I even watched Barrys DVD about sound. Thx! I call this diegetic and non diegetic sound.

That is an "academic" term. I have heard students go on about it but other than scollarly papers nobody working talks about it in those terms, that I have ever met.

The first is sound from a seen thing, what are generally called hard FX (doors etc.) and some things you don't necesarily see but they are part of "the world" of the film, like a radio playing. The other is stuff that adds texture and emotion to the "world". Tonalities and such.

 

[Jema]

Okey I get it! So for giving the audio signal a wide "tonality" you have to play with it's frequencies with an EQ, is that right? You "open" up some certain frequencies to make the signal more broad and defined? But don't you risk of changing the speakers voice by doing this?

Wether or not to use an EQ and to what extent, really depends on what the results should be and on what the sound source is like to begin with. First of all, many sounds don't have frequencies in the whole spectrum, so there may not be much there to "open up" unless you add them yourself through layering different sounds or special processing. Sometimes you don't have to use any EQ, sometimes you use it to make something sound less sharp, or less dull/muddy. If you are going for a change of perspective, you may intentionally limit the richness of the signal, for instance when making something sound farther away or coming through a wall. In that sense, it's more about balancing out a signal, removing deficiencies, and finding out what works for the scene. Add to this the fact that fx, backgrounds, music and dialogue may all play at the same time, in which case you may use an eq to make a chosen element cut through the mix (or not to), though this is often made through volume changes.

 

[KINOKS]

Great! Thx to everyone for contributing to this thread! I think I'm off to a great start, in learning about post audio. Not with this film though, I'm giving it to a pro to finalize! hahahaha But anyway, a lot of things were made very clear to me, so thank you!

I'll compile a short list of everything that was written in this thread shortly and if you'll have the time - please correct it if you'll see any wrongs...

 

[Noiz2]

...

If it has a place to be in the mix then yes, if not - then no! In one interview the crew was (except me) were sitting on chairs that kept making squecking noises through the interview. You know, when they moved a muscle the chairs produced a noise, and the sound guy, well, he did nothing This has to go out, any idea how to? There's probably lots of topic on the net about cleaning audio right?

But, regarding room tone, if there is music in the mix, you don't use it right? Only if it's low enough so that the cuts on the voice can be heard, only then you probably use room tone, otherwise there is no need, right?

I had to take off so I'll finish what I was going to say.

With the chair creaks IF they are not on top of the dialog then you can just cut them out and replace with some room tone. This is one of the cases where you really want to use actual Room Tone. You can often steal it from some "silence" close by.

If it is on top of dialog then there are a couple of options. You can use words from alternate takes, if you have any. Or you can ADR, again really only a narrative film option. Or you can use a tool like Rx by iZotope. It has a "spectral repair" tool that can remove sounds like the squeak with out trashing what you want to keep. I think Cedar has a similar tool ,at 10X the price. It doesn't always work but often it does.

RE: RT VS Music. Really two totally different things. And I suspect you are again saying Room Tone when you mean backgrounds.

It completely depends on the project. There is a low budget "style" that I think is very bad where folks slather music over large sections of footage so they don't have to do and sound work on it. It instantly turns you footage into a music video, and usually a not very interesting one. A full budget film will almost never use music exclusively except in the credit roll. Even music and dialog sounds phony if there aren't and sounds tying the viewer back to the "world" of the film.

One of the biggest things I would like no budget filmmakers to really understand is that production sound is NOT the "world" the story takes place in. In a documentary the production sound may be of the "world" of the film but not always. In a narrative film it's with a one in a billion exception never the "world" of the story.

So production is for dialog. RT is to help smooth out dialog, it has nothing to do with building the "world" your story takes place in.

Sound post is not mostly about cleaning up dialog or adding splashy FX. It's mostly about creating the world the story takes place in.

It's a concept only a handful of filmmakers fully grasp. But on a bigger budget film you have a big crew and they build that world even if the director doesn't really understand the full impact of what is being added. With no budget filmmakers you are usually dealing with a very inexperienced sound "team" (may just be the not so experienced picture editor) so if the director doesn't "get it" then it just doesn't happen.