Simple question concerning sound
 

As I have been reading alot of threads concerning microphone usage, I realize that I don't understand the process of how exactly sound from an off camera mic (on a boom pole) gets to the timeline of my editing program. Someone told me awhile back that I need a mixer and that the sound captured by the microphone is then taken to the mixer by which you have to do something with timecode etc...

Is it necessary for me to have a mixer? Or would it simply do just to have a hypercardioid attached to the end of a boom pole stragically positioned over my subject which is then hooked directly to my camera thus having the quality of a more adaquately positioned mic incoded with the film itself? Camera being Xh A1...

Will this do or will it be more complicated?

Thank you for your time and patience.
-Terry.

No need for a mixer or separate recorder. Just do as you suggest - plug whatever mic you decide to use (on a boom, a lav, radio etc) into your cam's XLR inputs and adjust the level. If you are just using 1 mic, (and if the XH A1 lets you) leave the built in mic recording to channel 2 as a back-up.

When you import the recording into your NLE, you will need to make sure it is handling the audio as 2 separate channels rather than a stereo pair.

Nick

Hey thanks alot Nick.

Alright so I can just simply take like a hypercardioid mic, plug it up to my camera's XLR jack, slap the thing in a shock mount and hoist it up over my subject via boom pole and I have then accomplished a more adaquate (more professional) way to record sound?

A mixer (hardware) operated by a mixer (crew member) would be helpful in that you'll more options and more control but it may not be essential - it all depends on the complexity of the setup. You'll need to pay a bit more attention (actually a LOT more attention) to mic placement and aim than just "hoist it over the subject" and if the subject is moving you'll need a boom operator to follow the action. And for the best results someone has to monitor what you're getting who is able to really devote proper attention to the job. But in essence getting the mic off the camera into a proper position near the subject, even though you continue to record in the camera using just its built-in audio circuitry etc, is certainly a big first step in the right direction.

Alright, Thanks alot Steve, mic placement is of course important. I will pay attention to that.

I remember you helping me out with this awhile back. You explained a bit about mixers however I think we were talking about a completely different camera at the time. I now am working with the XH A1, something that of course doesn't have the ability of timecode out. What I never fully understood (my fault) was the importance and usage of a mixer... From what I think I understand, the mixer simply records the sound seperately from the camera... I ask because now that I am going with simply getting a hypercardioid mic and sticking it on the end of a pole, I am curious as to what I am missing out on...

Thanks for your time Steve.
-Terry.

A mixer doesn't record anything at all. Think of it as a device for conditioning, amplifying, and controlling the signal before sending it on to whatever device is actually doing the recording, be it camera or separate recorder. You have 1 microphone - the mixer would provide phantom power for it, let you decide to put it on the left/right/both channels, provide an adjustable high-pass filter to help control wind and handling rumble, give you accurate metering of signal level and a convenient fader to adjust it on-the-fly riding gain through the course of the shot (assuming you had someone to actually monitor it constantly of course - camera op can't really do both at once), provide high quality headphone monitoring, and amplify the signal from mic level up to line level (if you choose) with a higher quality preamp than found in the camera. It provides limiters to control signal levels to prevent accidental overloading the recorder with unexpected high peaks. If you have more than 1 mic in use at once, it does all that and also lets you mix and blend them exactly together as you see fit. For example, I have the SD 442 which has inputs for 4 microphones and 3 pairs of stereo outputs (plus other output options). In a scene with 2 performers I could put a lav mic on each performer plus use a boom for coverage - the boom would typically be sent to the camera left channel while the two lavs would be mixed together and sent to the camera right channel. But I could change my mind and reverse them. Or discard the boom and put 1 lav on the left and the other on the right. Or a lav on the interviewer and cover the subject with a boom. Or in a multi person interview I could put lavs on up to 4 people and mix them together into a stereo mix to send to the camera, positioning them left/right/centre as appropriate. Wth 3 sets of stereo outputs I could send the same signal to 2 or 3 cameras in a multicam setup or record to a camera and to a backup recorder at the same time. It has circuitry to allow for proper setup and control of two mics for various stereo micing techniques, linking the channel level controls and limiters, as well as the decoding circuitry necessary to record and monitor stereo using the mid/side mic technique, something a camera by itself does not have.

Mixers themselves aren't involved with the timecode thing at all - TC is something that only comes into play when you need to sync the camera video with audio tracks that are being recorded separately to a stand-alone recorder and even there it's more of a luxury than a necessity. Even with TC in/out on the camera, it doesn't do what most people think it does and in most DV recording situations where there's a DV camera and a file-based recorder, all it really provides is a convenient slate to align the files, something that can be almost as easily done with an old-fashioned manual clapper board. Contrary to popular belief it does nothing to keep the sync from drifiting during the shot.

erm... well not exactly true. Usually the owner of the time code slates, lockit boxes, and master time code device usually belongs to the sound department (AKA mixer). The Mixer, or Utility person usually handles getting the slates, cameras, and lockit boxes jammed correctly So, we are are involved in the time code thing. Unless we're talking about the mixer device, rather than mixer person... It's so confusing sometimes. ;-)


Wayne

Hey Steve, Thanks for replying.

Just to clarify, The mixer is a device that allows you to condition the signal to however you see fit by allowing you to manipulate the sound on set. The TC is something that simply tells the sound file where the video file began and therefore enables them to be aligned. However, as you said, you could do this with an old fassion clapper board. Just clap the board before the scene so that the sound person will know where to align the sound file...

Just so I understand the relationship between the mixer and the camera; The mixer is hooked to the camera's timecode out which aligns the sound with the video. A recorder is then hooked to the mixer which records the sound file...

Did I totally butcher that..? sounds like I did :(

ROFL - Yep, I was referring to Mixer, the hardware device not Mixer the Person.

Totally wrong - the mixer (device) is completely out of the loop with regard to timecode and normally the timecode signals don't even come close to it. Your mic(s) connects to the mixer, then the mixer connects either to the camera's audio inputs if you're recording sound in-camera or to a separate audio recorder if you're recording double system. (Or you could do both if you wish - sometimes an audio guide track recorded in-camera is helpful in post even if your primary audio recording is done separately.) Meanwhile, back at the timecode terminals - a set of connections totally separate from the audio - you might be sending timecode from the camera to the audio recorder or sometimes it's done the other way around, generating the timecode in the audio recorder as master clock and jamming it back into the camera. But those connections are direct, not passing through the mixer. And they might not even be continuously connected - it's common to jam the camera and recorder so their TC clocks are set exactly the same and then disconnect them from each other, counting on the accuracy of the clocks to keep them running exactly in step for the next several hours. Of course, with most prosumer DV cameras it's moot because they don't have timecode in/out connections anyway. But in any case it would be incredibly rare for TC to be sent through the mixer alongside the audio.

Alright so mic hooks to the mixer, mixer hooks to the camera or seperate audio recorder ok got that.


So there is a seperate connection from the camera to the mixer that takes care of time code then? and this connection can be disconnected once the TC is jammed in both the camera and recorder. Jamming I am assuming is simply getting the sound file aligned with the video correct?


I think I got it this time!

So without the ability to get the time code out of the camera it would be difficult to record double system sound then...?

No no no - there is NO timecode connection to the mixer from anything, either camera or recorder. Zip, nuthin' nada. Timecode never touches the mixer in any way shape or form. If TC is used at all it goes directly between the camera and the audio recorfder - the mixer is not involved.

There is a timecode counter in the camera and one in the recorder, essentially very accurate time of day clocks. "Jamming" is the process of setting one clock off of the time in the other one so they are reading exactly the same. Like the old war movies where the pilots synchonize their watches before a mission. The audio alignment to the video comes much later, in post production. If you don't or can't use timecode you cxan still align the audio to the video through an old fashioned clapper slate. ("Mark it!" "Scene 3 Take 200!" "Whack" "Action!") Timecode is a convenience for double system sound, not a necessity. Movies were made with double system recording for more than 50 years before timecode was invented.

Uggh sorry Steve! I thought I had it that time. Ok NO time code to mixer. Mixer has nothing to do with time code. got it now!

Thanks alot for typing all that out for me!

I will be using just a hypercardioid that is attached directly to the XH A1's XLR jacks for now until I can budget a mixer and sound recorder. I guess this route will suit my needs for now.

You haven't said what camera you have, but in general double system sound doesn't make sense until you've mastered the entire rest of the process. For most people, this means holding off on buying a recorder and just recording straight to camera. I think the spending priority should be mics, boompole, mixer and then the recorder. Don't buy anything unless it's of decent quality. Also, rather than using a camera mic as a backup, I'd split the track and record at two different levels. In other words, take the signal from the mic and record it on both tracks with the levels at least 6dB apart, more if there's a wide dynamic range. This is because it doesn't sound like you have someone to properly monitor the levels. In post you pick the track with the hotter level unless it clips. Then you would use the other track, which hopefully had enough headroom.

The camera I'm using is the XH A1. So just by plugging two different mics into the camera I can have two different tracks levels in post? Thus I should choose between the two..

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.

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.

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.

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.

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.

Ah... The Bible.

Producing Great Sound for Film and Video: a book.

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

Thank you Marco.

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.

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.

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.

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.

What a fascinating world we live in...

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.

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

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.

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.

I honestly must say that the information given here is amazing. It is truly an honor just to be able to talk with some of the best and most knowledgeable people in the film and video industry. I could not have learned any of this without your help. It amazes me sometimes to realize that the very people I talk to in this forum produce, edit, and film or have taken part in some TV program I watched, movie I went to see or wrote a book I plan to read. How many people can say they talked to the guy who wrote a book on a subject? This opportunity is priceless.

Jack, thanks for the recommendations. I told my friend about Audacity and he downloaded it but hasn't had time to experiment.

Chris, thanks for your post. What you say is very true. I hope with the books you have suggested it will become clearer and I will be able to understand and ask more critical questions thus making better equipment decisions as well.

Gary, how awesome is that! I will certainly be Dean's book.

-Terry.

Terry... good luck on your audio learning adventure. There is SOO much to learn and know, but the journey can be fun and the results are easy to hear ! Remember good audio is a huge part of a good visual presentation.... almost sounds oxymoronish, doesn't it? It's true though.

One nice thing about Dean's book, as well as Ty's is that you get very useful hints on using a mixer and setting it up. So once you get your initial "sea legs" your next step will have a jump start. Dean's book gives very good advice on rigging lavaliers as well.

On that note... not a book but a great website with good (free) sound information can be accessed here:

Articles about Prod Sound

Not where I recommend you start your journey right off but pretty quickly you will find their info useful. (It was the rigging lav's thought that made me think of this site....glad I did, they keep adding to it.)

Chris

ps. In time you will fall victim to the "which mic is best?" or "or which mixer is best?" arguments on here. That is a place where your new knowledge will be an asset. (It's like the old FORD versus CHEVY arguments of shadetree mechanics... with a few folks who will explain why Rolls Royce is superior - and of course they are right. Always fun though.)

pps. No one agrees on any of those questions mostly.... with exceptions.... (eg. SD302 - that will make sense in time.).

ppps. Dan Brockett had done a number of microphone comparisons where you use YOUR ears to compare... they can be found at www.kenstone.net. (and another THANKS to Dan for the work and help offered.)