Postproduction basics

KINOKS

KINOKS

Well-known member
I'm a producer with lot's of skills: editing, colouring, screen writing, lighting, etc. But there is one production genre that I've always been lacking at and that's the sound department. In the last year or so I've come along way forward regarding location sound recording but I still don't know much about sound in postproduction. So this is why I've decided to finalize a short project I've been working on by my self. As a producer I think that I just can't let myself have such a void in this department.

I'm asking for a bit of help (obviously). I need to know what are the basics or the things that must be done in post-audio. This is what I know so far:

- compressing audio with a compressor
- gaining to have the same sound levels (or is this all done with a compressor?)
- mixing (don't know much about it...)
- removing noise
- doing foley
- using a EQ to boost desired frequencies and to remove the undesired ones (don't know much about this either:))

I'm editing in MC6 but unfortunately I don't have PT at my disposal only Adobe audition and the project I'm working on is a short documentary.
It's got music, IT and talking heads but no voice over. The film is going to be broadcasted and I am going to have it looked at by a professional beforehand! The TV house has a standard of -8dBu. So this means that the peak should be at -9 wright?

So can anybody help me to get started please?

I've got some initial question already:
- do I gain in MC all the track to get the levels in the same ball park before going to Audition?
- Do I even have to go to Audition? The noise levels on the audio seem O.K. to me.
- How do I compress the audio? MC has a compressor so I'll probably use that. I know how it works and everything, I just don't know any trade secrets or established ways about using it.
- How do I mix the audio - must everything be heard on both speakers? Do I just pan the tracks on centre or do I duplicate the tracks?
- The talking heads go up to -9dBu but what about music and IT? as an editor I usually put it 6 or 9 dBu below the voice over or talking heads in other instances I go by felling.
- Any useful links?

Thanks!

Br
S
 
Last edited:
I think it's good that you are trying to increase your knowledge, and I hope it goes well for you. Since your questions are quite basic, I really recommend that you pick up one or two books on the subject. Sure, you can get a lot of information and good tips by reading forums and articles etc, but it will take more time and require you to assemble a lot of pieces into a more coherent picture. A book will have most of the information you want, in a good structured way.
Read this thread:
http://jwsoundgroup.net/index.php?/topic/5940-ultimate-beginners-guide-to-recording/

I think a good place to start is Audio Postproduction for Digital Video by Jay Rose.
 
Thanks for the recommendation Jema. Looks like chapters 12 to 18 would be of use to me. At the moment I can't afford the time to read a whole book, so I'm really looking at some shortened guides more so than books, but I'll have a look at this anyway. Thx.
 
You should hire a professional audio post engineer. If something is wrong, the project could be rejected, then where will you be.
Post audio is difficult enough and one should have a tuned room with multiple monitor options. Using compression without experience is like a kid with matches.
Regarding -8dBu, I would guess... it probably means 'program peaks not exceeding -8dBFS', based on a -18dBFS reference. However many networks have changed their submission audio specs to the EBU R128 or ATSC A/85 loudness scale.
Good luck.
 
Last edited:
Rick R said:
Using compression without experience is like a kid with matches.
Click to expand...

... in a room full of gunpowder and gasoline.


Definitely retain someone with more knowledge than you have. Broadcast standards are tricky enough for those who know what they are doing. For a newb it's wading into a crocodile infested swamp with a steak in your back pocket - you're gonna get bit in the backside!


Take the time to read a few books and forums like this, get some basic gear and start experimenting. Then work with a professional again; the light bulb will really go off!

Here's a few books:

The Practical Art of Motion Picture Sound - David Yewdall
The Foley Grail - Vanessa Ament
The Sound Effects Bible - Ric Viers
The Production Sound Bible - Ric Viers
Sound and Vision - Michel Chion

Also "hang out" at:

http://filmsound.org/

http://jwsoundgroup.net/
 
admire your diy spirit but there's no quick and dirty way to mix something down sorry

if there was my techno songs wouldnt have sounded like banging tin wrapped in mush for 5 years (they sounded GREAT on my boom box tho hhmmm)

its not something you can do with a butterknife you use a scalpel
 
Last edited:
Haha I knew you were going to say that!:) Thanks for all the nfo! But besides telling me to hire a professional or to read a book (which I know are the right things to do without anybody telling me) could somebody actually help me?:) Just think of me as a producer who wants to know more about what are the people he is hiring actually doing for him + it really bothers me that I can't judge for my self if the audio is good, bad or mediocre, etc... If I'll see along the way that I won't be able to manage the project myself or if the end product wont be good enough I'll definitely get a professional to do it!

So what are the typical things that are done to audio in post?
 
There are tried and trusted workflows for post and they usually involve using a dedicated audio editor for a reason as you then have the right tools for the job.

Yes you may get away with throwing something out of your edit system with a compressor slapped onto it but it will be like trying to perform dentistry with a screwdriver and a power drill.

I have been doing post for over 33 years now and I am still learning new ways of doing things but the basic principles remain the same and as said you are best starting off with a book to pick up some of the basics.

Then like all of us you have to apply the theories to the specific equipment and projects that you have to deal with in the same way that we all have had too.

There are so many variables to try to explain things on a forum is just too much of an ask, it's like saying I shot some material now how do I make it into a movie?

If you are doing this professionally and you now need to add post audio skills to your business then you need to go on a course and learn how to do it properly rather than hearsay or tips on a forum and that training needs to take into account your systems and applications.

It then may be that like most people you will find that what you need to do at a professional level requires some further investment in the right tools to achieve the results that are demanded by your broadcast delivery!
 
Last edited:
Regarding how to judge if the audio is good, this is as hard as saying if a picture is good or not. As the saying goes, if it sounds good then it is good (for film you should only add "and if it works for the story"). Just because something is processed like there's no tomorrow doesn't mean it's better then it was unprocessed - that's the reasoning behind the "kid with matches". As an anecdote, a while ago I was watching an early version of a project I was the location sound recordist for, but had nothing to do with the post. In one scene there was a close up on an orc-like creature speaking a harsh language, and I was quite impressed by the aggressive and full sound. Right after the credits I asked the director what had been done to that voice, with the reply: "Nothing - it's the raw track".

A tip: One way to judge the sound is to compare it to similar works (preferably for the same mode of distribution and budget - there's a big difference between web videos, commercials, TV, and drama). Also, don't be fooled by how loud something is - psychoacoustically we are inclined to think of loud as good (one reason why commercial CD:s are compressed so much), so adjust it to similar levels.
You also need good speakers and a room treated for listening.
 
How come you can ask ANY random question about filming/video, be it camera settings, color correction workflows, special effects, 3D animation or even hacking the firmware of a camera and get an answer?
How come you can also ask anything about recording sound, which mikes to use, which polar pattern, booming techniques aso - but the minute you ask about the basics of audio post (most of the time cleaning up dialog and "enhancing" voices) there are red flags shooting up everywhere...?
For probably 99% of questions asked here, you could simply answer: "Hire a professional (fill_in_blanks)".
We all know that each of the respected fields of filmmaking is a viable profession of its own, with a lifelong learning curve.
Nevertheless to a certain degree, we´re all wearing different hats theses days, I guess that´s why audio guys are active in a (formerly) camera forum like DVXuser.com

This mystery surrounding audio post is utterly silly and should be moved to a freemasons forum...

If they exist of course.
;o)
 
Ok Spartacus if it's that easy go and set up an audio post house! or just buy one of those auto mixers and try do a feature film ;0)

Video and location audio is one thing but dealing with audio post has so many variables that to attempt to resolve them on a forum is just silly and if the OP is wise he will take the advice and read some books on the subject as many of us have recommended!

No dark art at all but it takes many years of training and expertise to get to be a good audio post mixer and sadly there is no quick fix for such experience.

As for the basics you do this:

1: you record or receive good clean audio for the production
2: you track lay that audio and smooth it to suit the production
3: you add any music and effects to suit the production
4: you mix and balance the audio to suit the production
5: you get the client to agree that they are happy with the audio post for their production
6: you deliver the mixes as specified by the production

Anything else is down to what kit you have at your disposal and how you use it or you buy a nice auto mixer! ;0)

Here's a video tour of my own old audio facility in London from a few years ago that may give some insight into what we do in audio post: http://www.youtube.com/watch?v=u1DUmtDs2cI

and this is what I use now : http://www.youtube.com/watch?v=Ns-tQPrOcjE

it's all just technology though and the basic principles can be read in books as they have been defined since the 1940's

Now who can tell me how to grade my film ? I have a computer and a TV so I must be able to make it look great!
 
Last edited:
Jema said:
Regarding how to judge if the audio is good, this is as hard as saying if a picture is good or not. As the saying goes, if it sounds good then it is good (for film you should only add "and if it works for the story").
Click to expand...

Well I didn't mean it like that, at least not exactly like that. For instance: I know when a picture is to compressed, I know how it looks like when highlights on skin tones get to compressed because of improper exposure when shooting with LOG, I know when a picture hasn't got enough mid tones, I know when there is a colour cast present, etc etc. I know nothing of this sort regarding audio. As for the if it works for the story...that's a whole different argument, I understand yes...

Spartacus said:
How come you can also ask anything about recording sound, which mikes to use, which polar pattern, booming techniques aso - but the minute you ask about the basics of audio post (most of the time cleaning up dialog and "enhancing" voices) there are red flags shooting up everywhere...?
For probably 99% of questions asked here, you could simply answer: "Hire a professional (fill_in_blanks)".
Click to expand...

Don't want to be negative or anything but this is my impression to.

GaryNattrass said:
Now who can tell me how to grade my film ? I have a computer and a TV so I must be able to make it look great!
Click to expand...

Sure I can help!
1. With what equipement are you working with (hardware and software), what are you trying to achieve and how much time do you have?
2. There are some basic things you must do in post:
a) make sure all the shots match up regarding colour and contrast. This is usually also the first thing there is to do when dealing with picture in post.
Correct the colour and then correct the contrast. This is called primary colour balance.
b) when you've matched up the shots it's time for secondarys... This entails: giving the pictures a specific look. You can change the saturation, contrast and colour of the image and then you can further use keys and vignettes and trackers to achieve what you desired goals. But hence you probably aren't asking about about grading but just how to do simple primary correction to make the picture look overall good - the stuff that must be done - I'm not going to go further in secondarys.

What you need to do when talking about primary correction is: white balance the shots. For this job use curves, levels or HSL. In this process don't just relly on your eyes bacause they addjust to the picture quickly making you think it's o.k. when it's actually not and also your monitor maybe isn't showing correct colours so you should rely on graphs and meters such as waveform, RGB parade (this one is most useful for doing colour balance) and vector scope.
Then push the whites (the brightest areas) in every shot so they reach the top of the waveform or the far right corner of the histogram. But be careful don't clip (lose) to much data in those highlights. Then do the same thing for the blacks. Make them black. But you should always keep as much midtones as possible (generally speaking). Midtones are the values between the darkest and the whitest parts of the image. It's the area where most of the information should (again this is generally speaking) be.
When you've done the colour balance and contrast adjustment you should have a look at the saturation. Adjusting colour and especially contrast has a big effect on saturation of colours. They can easily become to saturated. So now it's time to desaturate some shots using. In some shots there are maybe only certain colours that need to be desaturated not the whole image. When adjusting contrast skin tones can get to saturated, to red, so it can be a good idea to desaturate the reds. How to know if a certain colour is to saturated? One way is to use your eyes and the second is to use a vectorscope. If a colour passes the edge of the vectorscope it's illegal for broadcast and it needs to be taken down a notch. The same goes for luma levels. For broadcast they shouldn't go above 235 and below 16. Although this depends on the region you live in and it can vary from broadcaster to broadcaster... But be careful when desaturating skin tones. Peoples faces can quickly look like they are dying or something. Don't desaturate to much!
If you need help on how to colour balance just ask. And please tell me what programs you are using so we can advise you better on your workflow.
Also when doing colour correction it's quite possible you'll bring out some noise in the picture. You should take care of that if it gets to "nasty"...

Wrote this in 5 minutes. If I really would have wanted to help somebody I would make it more in depth and offcourse I would want to know before writing this what programs he is using what kind of set-up he has, with what was the material shot in what codec he's got his material in, etc. etc.
 
I don't want to be mean Garry:) I know it's complicated, I think I can relate. But I cant read a few whole books at the moment. I will in the future but just not now. I can read some specific paragraphs or chapters with a specific goal in mind but I really can't afford to read books from top to bottom. If I had time for this I would already be doing it and I wouldn't have opened this topic...:)

If you guys think that you can't help me then I won't push this any further. Thx anyway.
 
Spartacus said:
How come you can ask ANY random question about filming/video, be it camera settings, color correction workflows, special effects, 3D animation or even hacking the firmware of a camera and get an answer?
How come you can also ask anything about recording sound, which mikes to use, which polar pattern, booming techniques aso - but the minute you ask about the basics of audio post (most of the time cleaning up dialog and "enhancing" voices) there are red flags shooting up everywhere...?
For probably 99% of questions asked here, you could simply answer: "Hire a professional (fill_in_blanks)".
We all know that each of the respected fields of filmmaking is a viable profession of its own, with a lifelong learning curve.
Nevertheless to a certain degree, we´re all wearing different hats theses days, I guess that´s why audio guys are active in a (formerly) camera forum like DVXuser.com

This mystery surrounding audio post is utterly silly and should be moved to a freemasons forum...

If they exist of course.
;o)
Click to expand...

Well you can ask the first batch of questions to sound folks and get "answers" but don't go asking them to professionals and not expect to get flamed.
Sound isn't any more mysterious that a DP's knowledge of film stocks and DOF and lenses. Neither has any simple answers.

But now everyone is shooting on video and you can salvage badly shot video better than baddly shot film. Partly because most video is shown on small screens. BUT audio playback quality has not shrunk to a small screen. Sound on tiny speakers does not sound sharper and clearer than it would on a big system. Actually it's kind of the reverse.

So while video folks can often get away with murder, compared to 35mm film, sound didn't get any easier. The techniques that worked 50 years ago are still largely the techniques that are used today. The tools have gotten MUCH better but you still have to know how to use them.

The OP is basically saying I want to build a house and so what hammer do I use. It's an inherently unanswerable question. IF you have the answer, go for it.

The quick answer is IF the OP is heading to public access then maybe he should just go for it. If this is heading to an outlet that is actually going to have standards then he probably should get some help from someone who knows what they are doing.

The folks who are answering questions here often have years of experience. They have amassed effectively advanced degrees in sound, some actually have them. Just as a doctor would be irresponsible telling you how to perform surgery they are trying to not be irresponsible telling the OP some capsule "trick" that is as likely to get him in serious trouble as to "solve" his problem.

TO OP,

There is a bunch of stickies at the top of the forum, and at least one is about post sound. That would be a good place to start. But it takes a lot of knowledge and experience to do a good job on post sound so no amount of reading or advice is going to get you there.
 
There are tons of great resources for learning audio post-production skills. There will always be people who want to shroud their skills in mystery and awe to try and preserve their livelihood. Don't let them deter you. What they do is technical and artistic, just like everything else in film. There's no magic.

I just completed post-production for a 15 minute short film and I've learned a ton. It's not perfect, but it sounds good and really serves the story. You can learn everything by doing. Practice on things that don't matter and then you'll be ready for the things that do.
 
I agree with the lack of "magic" but that doesn't mean anybody can just istdown and with a few quick answers on a forum do a good job on sound post. Pretty much anybody though can sit down and do a bad job ;~)

And actually you are saying the same thing. Practice and get better. However the OP wants someone to tell him the "secret" so with no experience and the wrong tools he can do a great job. That just isn't realistic.
 
it is amusing though that most audio post done by me and my pro colleagues these days is more audio recovery of self shoot G2 and rode video or cam mic run and gun! That says more about the state of the industry and is probably why I now also do camerawork and editing.

That linked with poor OMF export and the inability of most producers to understand the skill and value of audio post also means that an awful lot of mainstream programming is un-dubbed in the UK these days!

C'est la vie as they say but to do it to a decent level involves the understanding of the basic principles rather than a few s and tricks on a forum that may be irrelevant to a particular project if translated wrongly!

I stand by my tips above and audio is more about prep listening than pure tech or software and regardless of technology I ll dub the same way now as I did with three track sepmag in the 80's
 
Last edited:
A lot have been said and I think the general message has come across. I'll try adressing one of the questions.

quote_icon.png
Originally Posted by Jema Regarding how to judge if the audio is good, this is as hard as saying if a picture is good or not. As the saying goes, if it sounds good then it is good (for film you should only add "and if it works for the story").



Well I didn't mean it like that, at least not exactly like that. For instance: I know when a picture is to compressed, I know how it looks like when highlights on skin tones get to compressed because of improper exposure when shooting with LOG, I know when a picture hasn't got enough mid tones, I know when there is a colour cast present, etc etc. I know nothing of this sort regarding audio. As for the if it works for the story...that's a whole different argument, I understand yes...
Click to expand...
Ok, so you want to know what possible deficiencies to listen for and how they sound. Here are some things you might think about:
First and foremost is the dialogue, which is usually a key element in driving the story. Is the background too loud, making it less intelligible? Are there any distracting noises that should be removed? Does the tonal quality or level change a lot at any given point between actors or between shots? Does it change at all and follow the perspective of the shot (wide shots sounding more distant than close ups etc)? Is the tonal quality balanced, or does it all sound a bit sharp, tinny, or muddy? Ultimately, can you hear what they say without making an effort?
As to fx and music, these are very much in the artistic realm and there are few rules. Does the levels work, or are some things to loud or soft? Is something panned in a funny way? Does the fx seem like they belong to the things causing the sounds (a gun sounds like a gun and not something else) and originate from the filmic world, and if not, is there an artistic reason for it?
Wrong usage of common processing tools like eq, compressors, gating and noise removal are easiest learned by trying it out yourself. Take an audio track and play around with it, and notice what happens when you do too much.
 
You must log in or register to reply here.
Back
Top