Simple question concerning sound

[Marco Leavitt]

I'm retyping this after rereading your post. Sure you can use two different mics. I'm saying use one mic, but route the signal to both tracks using different gain settings so one is hotter than the other. This is essential when you don't have a separate person monitoring your audio.

[Steve House]

I concur with Marco's advice, it's spot on. Interpret my posts as discussions to educate on the technology of single and double system and timecode's role, not recommendations as to the best way to start setting up up your kit. I'll definitely go along with the suggestion of getting a mixer and defer thinking about a recorder for double system until you're a lot farther along. A mixer would let you split the signal properly so you could send the same mic to both channels in the camera so you can to use the multi-level technique he suggests as well as offering the other aforementioned controls.

[Paul R Johnson]

Personally I cannot see the point of recording the same source to two channels at different levels, just in case you go over. If you want to record sound manually I take the point, but surely any form of manual sound control during record compromises the picture as in I need to focus, zoom and bring the level down all at the same time - which one don't I do?

If I do use manual, the dynamic range of digital audio is so much better than noisy old analague that under recording isn't the problem it used to be - you have a fair bit of lattitude for bringing back up without it sounding poor. If you are really worried, then the limiter works pretty well, and I guess if really, really worried, then agc. Putting agc'd audio back to it's proper range is easier than trying to salvage a badly over or under recording.

[Marco Leavitt]

Remember that a digital audio track has a finite bit depth. Also, the noise floor is constant, no matter what you are peaking at. You want as much amplitude between your peaks and the noise floor as possible. If you record very low levels and then try to raise the volume in post, all that noise will come right along with it. Optimally, you want the hottest recording you can get, without peaking out. As you say, the one person operator just doesn't have the attention to really keep an eye on it. Recording at two different levels gives you a reasonable margin for error. AGC works, but it often raises the ambient (background) noise to an unacceptable degree as the gain pumps up and down.

[Terry Lee]

As I read this stuff I realize that there is alot I do not understand about the sound department in the digital realm.. Instead of asking 100 questions about every thing I don't understand about your explinations, is there a good book that explains this process pretty well?

Thanks,
Terry.

[Marco Leavitt]

Ah... The Bible.

Producing Great Sound for Film and Video: a book.

[Terry Lee]

Perfect! It even has a CD with examples and stuff.

Thank you Marco.

[Terry Lee]

Well yesterday after explaining what little I know about how important the neglected aspect of sound in film is to a friend, he asked me "alright so you have all these components when working in the field (mic, mixer, boom pole etc..) but what do you do when you get back to your computer to edit and hear all sorts of scratchy stuff, back ground noise you didn't hear when recording? My answer to that was just bad sound recording because the mixer (person) didn't didn't do his job well. What he was eluding to was what about post production. If you have all these tools in the field, what are people using back at the office? I honestly couldn't answer him. People aren't simply just clicking and dragging etc.. in their vegas/FCP editing suits are they? I am assuming there is some sound boards involved...but i've never gotten that far..

Thanks for your time.
-Terry.

[Seth Bloombaum]

Originally Posted by Paul R Johnson

...surely any form of manual sound control during record compromises the picture as in I need to focus, zoom and bring the level down all at the same time - which one don't I do?...

Putting agc'd audio back to it's proper range is easier than trying to salvage a badly over or under recording.

Marco was too restrained in his response to this. Paul, your concern for the image is admirable, but suggesting that use of AGC is a decent compromise for a one-person camera/sound operator is not an acceptable approach for the people I work with and for, and for good reason! AGC has the same problem other automatic camcorder functions have - unpredictable results. Now there are times where sound doesn't matter so much, but if dialog is involved... Using AGC is like using autofocus - your subject may be in focus, or maybe it will be the wall behind them. Or auto-iris, something seems to go funny when the subject walks in front of a window. Or auto-gain, why is this shot so grainy compared with the others?

The effect Marco referred to, sometimes known as pumping, can easily be eliminated by using manual control of audio level. Even as a one-man-band, as you gain experience with a particular mic/camcorder combination, you'll know how to set a gain to peak appropriately, and you won't need to be constantly riding it. Just keep an eye on the meters.

Originally Posted by Terry Lee

...If you have all these tools in the field, what are people using back at the office? I honestly couldn't answer him. People aren't simply just clicking and dragging etc.. in their vegas/FCP editing suits are they? I am assuming there is some sound boards involved...but i've never gotten that far...

Vegas - people are just clicking and dragging, it's pretty decent for audio editing.
FCP - most will stay with FCP as far as they can, but export to Soundtrack Pro for the hard stuff.
Protools is the standard audio editor across many industries, it used to be that the editor would pass off a project to an audio engineer in a protools suite for "sweetening", but these days more projects are being finished by the editor.

But soundboards? No, not unless there is original music, sound effects or voiceover being recorded in-studio. I've got a tiny sound board aka. mixer aka. console aka. mixing desk next to my NLE, but most of the time it's just a convenient place to adjust the volume of the monitors.

Monitors and a good sound card are where you can and should spend some money in outfitting a post suite, and there's lots of info on this forum about both.

[Steve House]

Actually it is totally possible to do the post completely "in the box" using just the mouse and keyboard without any mixing desk sound boards or other hardware processing like you see in recording studios, etc, being required. As Seth says, a compact mixer can be handy if you're recording in studio or want to mix the old fashioned way in the analog domain. I have one, a Mackie 1642, and like he says with his, other than recording VO I end up just using it as a monitor controller 99% of the time. A desktop controller like a Mackie Universal that replaces mouse dragging in the software mixers is handy and makes the job go easier but is by no means a necessity. You do need a good quality sound card or audio interface and proper studio monitor speakers - OEM soundcards of the sort that come with most computers leave a lot to be desired and computer shop 'multimedia' speakers, even the pricey ones, are NOT adequate monitors - but that's really it in terms of audio hardware that's absolutely required. (Recording voiceovers and dialog replacement adds a few other odds and ends and convenience items but even there, selecting an audio interface with a decent set of mic preamps on its recording inputs covers the majority of what you really need). Video NLE software such as Vegas, Premiere, Final Cut Pro, Avid, Edius have very powerful audio tools in addition to their video capabilities and when you couple them with audio specific programs like SoundForge, Audition, ProTools, Nuendo, etc and you have software capabilities whose hardware implementations would have cost perhaps hundreds of thousands of dollars back 20 years ago in the analog studio days. Add to them the audio addins, tools, and utilities that are available from folks like Waves, Izotope, Bias, etc and there's damned little you can't do in the computer.

That being said, the real answer to your friend's objections about the "scratchy stuff, background noise, etc you didn't hear on location" is you have someone on set to handle the audio who knows what he's doing and who can monitor continuously with his full attention devoted to the sound you're getting so you don't bring home tracks like that. Post can't work miracles if the production sound is cr*p to begin with.

[Terry Lee]

What a fascinating world we live in...

[Jack Walker]

Jay Rose has a second excellent book that is specific to post production sound:
Audio Postproduction for Digital Video: a book

Follow Jay's link to Amazon and read the table of contents headings for an overview of what's involved in post production sound. You'll also see the very issues you mention covered by topic.

The secret to early success is to get a basic overview, then narrow your study to exactly what you want to accomplish with the sound.

The basic tools are:
--computer
--pro audio interface (sound card with input and output)
--video editing software
--audio editing software (e.g. Audition, ProTools, etc.)
--specialized software plug-ins (though not necessarily necessary)
--flat response near-field (close range) speakers
--v.o./pick-up/sound effects mic
--micport (e.g.) for recording into laptop on location(may be covered by audio interface on computer or other portable recorder or a camera could be used)
--sound effects and music (e.g. Digital Juice, SmartSound, etc.)

An excellent audio interface (sound card with multi-track input and output) can be be bought for $200-$700. They usually come with basic audio software (editor, sequencer, mixer, etc.) to cover general needs. (Audacity is the popular free program that is excellent and can be very useful in many situations: Audacity: Free Audio Editor and Recorder)

I have found that nothing about audio, except where it digitally clips, is concrete. Everything is subjective and everything interacts with everything else. That's why I suggest getting a basic overview, then looking at a very specific issue and begin with that. Audio is very uncomfortable to deal with until one has a lot of experience.

[Chris Swanberg]

You have gotten some very good advice from some very knowledgeable members. I suspect some of this may seem overwhelming... I suggest you start your education in this order:

Learn about microphones first. Dynamic microphones and condensor microphones. Pros and cons of each. This is also where you will learn about "phantom power".

Then learn all about condensor microphones - pickup patterns first: Omni, cardiod, hypercardiod. Find out the benefits and drawbacks of each and where each is best suited for use.

Then learn about the types of condensor microphones: Shotgun microphones, studio microphones, small element microphones and large element microphones. Lavalier microphones, wired and wireless. (There are a couple of others but you won't need to know about them now - like PZM)

Then look into ways of handling those microphones, like stands, clips and booms, and ways to protecting them from wind, such as foam covers, "softies" and blimps.

Finally acquaint yourself with XLR cables and learn about balanced and unbalanced wiring.

It sounds like a lot but isn't really... but that is a good place to start your education in an systematic order rather than jumping into the deep end of the pool IMHO.

By the time you complete this you will have a much better sense of what the tools of sound acquisition are all about.

Then you can learn about digital recording - mixers and all that.

Jay Rose's book recommended in this thread is indeed a classic and excellent and will teach you most of the above things. Mine is dogeared and I still learn something every time I re-read portions of it. Also, read the threads here as the titles suggest themselves to you - meaning there are threads here which discuss some of the above things I mentioned. Look and you will find them.

Once you read that and understand it you will better understand the wisdom of such things as splitting a single audio signal into your digital camera on two channels and recording one hotter than the other. Terms like noise floor, signal to noise and clipping will have much more meaning. Most importantly your sound will be MUCH improved. Plus, you will know more and make better equipment choices with the knowledge base you will have acquired.

By then you will probably also have a slew of other questions, but also will be better equipped to understand the answers given you as your knowledge continues to grow.

Two other books I recommend for explaining how to USE the tools you will learn about (and I am sure acquire) are Ty Fords location audio manual entitled Audio Bootcamp Field Guide AudioBootcamp.html and an excellent location sound book by S. Dean Miles entitled "Location Audio Simplified" (www.locationaudiosimplified.com).

Also, forget worrying about timecode. I won't say it is irrelevant, but rarely necessary. Synching two channel sound with todays crop of editing programs is not all that tough. And for now you will be recording direct to the source tape/medium so it will be laid down in synch.

Chris Swanberg

[Richard Gooderick]

Originally Posted by Chris Swanberg

Two other books I recommend for explaining how to USE the tools you will learn about (and I am sure acquire) are Ty Fords location audio manual entitled Audio Bootcamp Field Guide AudioBootcamp.html and an excellent location sound book by S. Dean Miles entitled "Location Sound Simplified" (www.locationsoundsimplified.com).

Chris
I think it was very late when you wrote this. The link isn't quite right. I think this is the correct one:
Location Audio Simplified

Thank you for the recommendation. I'm going to buy it.

[Gary Brun]

You can also buy it from Trew Audio.

The book by S. Dean Miles is a excellent book.
Just to tell you something a little about the guy who wrote it and what sort of guy he is.

I bought his book and was travelling from the USA to Norway.
The book was great but I was really gutted because when I got home I realised as I had left my book on the plane :-(
So I contacted him for a new one...guess what??
He sent me a new one and all I had to pay for was postage and packing.

The book is an excellent read and I have learnt so much from it and would recommend it for anyone to have in their resource library. Its written in plane English with excellent examples. and has helped to really transform our productions.