audio levels

HerzogisGod

HerzogisGod

Well-known member
i use an hvx200. obviously i record keeping the level bars from hitting the red peak zone. but i do tend to record very close the red zone (without touching it)

sometimes my audio sounds distorted when played back on speakers, so I just lower it and it seems to be okay. It cant be distorted, right? i mean, if Im not hitting the red zone, then distortion is not possible....it's simply "loud"

just checking
 
If you turn down the volume when played through speakers and it sounds OK, then I'm guessing that the distortion is in your speakers at high volume ... not your recording ...

-R
 
HerzogisGod said:
It cant be distorted, right? i mean, if Im not hitting the red zone, then distortion is not possible....it's simply "loud"
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Not necessarily. If the audio was distorted somewhere upstream in the audio chain, then it doesn't matter where the levels are on your camera.

What is the rest of your signal chain? Shotgun mic to mixer to camera? Wirelss mics?
 
I was reading into the statement that it "seems" okay. Could be distortion that is not clearly audible at lower levels. Also, the point needed to be made that just because the meters on the camera say the levels are safe doesn't mean that the signal wasn't messed up somewhere else.

The best way to figure out where distortion comes from is to start at the source of the audio chain and work all the way downstream.

The other question that needs to be asked... do other sources known to be clean also distort when playing at the same levels over the same monitors?
 
My speakers are crappy, $20 best buy speakers. Im gonna invest in a good set this week.

I just want to be sure that only tapping into the red zone will produce distortion. I like to run my audio overall "hot" meaning close to the red limit but not tapping into it. I find this gives me more freedom in post. But I could be wrong.

When I used to allow my meters to bounce around near the center point I found the audio was too low overall, just not satisfactory.

thanks for the feedback. i will invest in good speakers and try more tests.

any speaker recommendations?
 
I use a pair of Mackies MR5 studio monitors with my MAC. FCP editing.

I think they are great for the money!
 
HerzogisGod said:
I like to run my audio overall "hot" meaning close to the red limit but not tapping into it. I find this gives me more freedom in post. But I could be wrong.
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I don't know a lot, i'm still a newbie, but I think that your levels should be lower in recording, so you wouldn't have any problems with clipping (if an actor shouts, for example) and you can normalize the sound in post.
I think you should keep the level at least under -12dB.
 
if I know my actors are going to yell....I set the level for that range before we start using a simple sound check. Then i check again while filming to be sure they arent peeking when they are raising their voices.
 
Your levels should be at the reference mark, and not riding so close to clipping. While the levels may seem low to you in post, it is digital audio so there will be no noise added by bringing the levels up if needed.

But how far up do you need to bring the audio levels? To what level are you mixing that -12dB is too low?

EDIT: $20 computer speakers won't tell you a darn thing about what's really happening with your audio. If you need critical monitoring, go with Genelecs or some other true studio monitor that's designed for critical monitoring (note: this also requires proper setup and treatment of your edit space, since great speakers in a crappy room will be worthless). If you need only an idea of what's happening before you send your projects off for audio post, then something like the Edirol MA-15D speakers will give you decent playback at a pretty low price. No, they aren't accurate like the higher-end stuff, be they're far and above anything you'll find on the shelf at Best Buy.
 
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C2V said:
Your levels should be at the reference mark, and not riding so close to clipping. While the levels may seem low to you in post, it is digital audio so there will be no noise added by bringing the levels up if needed.
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I'm really new to audio, too. What do you mean by the "reference mark?" I've been learning as much as I can and Barry Green's Sound For Film and Television was a HUGE help.

I've also been getting as close as I can possibly get without clipping and that seems to have been a mistake. Is it best to get slightly over -12 db?

Here is a short video with 3 different samples of what I've been getting.

http://mattadamsapple.com/dvxuser/levels.mov

For the first interview I'm using an ME-66 on a boom stand. for the second I'm using an ME66 as well but am booming it by hand and for the third interview I'm using the Rodes NTG3 with the blimp system on a stand.

For the last interview I made the rookie mistake of falling in love with the location and didn't take into consideration that it was a poor sound choice.
 
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-12dB is your reference mark. Ride as close to that as possible, and don't be afraid of the occasional peak above -12 (sudden shouts or other loud noises). Sudden peaks can hit as high as -6 and still have some decent headroom. Technically, you can ride to -1dB without clipping, but headroom is important and pushing it that close is merely tempting fate.
 
Easiest solution (if you have money): Hire a mixer with real gear. He or she will worry about all this crap for you..

If that is not an option then do what you can, a lot of this advice is good. Running out and buying new speakers isn't going to do anything to make overloaded audio sound any better, and a $100 set of headphones (7506) is all you need to know if your sound is "good" or not (I mean overloaded or not). Recording hot is always a good thing until you clip on that important bit of dialogue, which will later force you into re-recording or hiring adr work, and you'll spend more time and money on fixing it (poorly) later on. Of course I have no idea what you're shooting, if its weddings or home videos then who cares, but if you want to show this to people then I would be a little more careful. Bad sound sticks out like a sore thumb (especially when the picture is hi-res) and drives your production value into the toilet. I know it scares the **** out of me when a production wants me to connect wireless recievers straight to cameras without anyone critically monitoring (I don't expect the camera man to really be responsible for monitoring) because all it takes is one loud shout or laugh and there goes your audio. Set it to auto gain and hope for the best in those cases, I know sooner or later there will be a nasty note from post waiting...
 
HansonD said:
Running out and buying new speakers isn't going to do anything to make overloaded audio sound any better, and a $100 set of headphones (7506) is all you need to know if your sound is "good" or not (I mean overloaded or not).
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If you are mixing your final audio on headphones, you're in trouble... no matter how good those headphones are. They should stay plugged into the camera during recording so as to detect problems in the field. In post, headphones are used for checking subtle things that the reference monitors don't expose, if they're used at all.

But we are talking about some one who is doing the post as well, and crappy speakers will tell the editor nothing about the audio. $20 computer speakers, besides sounding terrible, have a couple of problems. First, they tend to overmodulate very easily at higher levels. Second, they often don't drive hot enough for any really critical listening. Every edit suite should have good speakers. Audio post suites must have great speakers.

So while better speakers may not make bad audio sound better, they are a more reliable reference point for troubleshooting audio issues.

Hiring a good sound person for the shoot, by the way, is always the best option.

HansonD said:
Set it to auto gain and hope for the best in those cases, I know sooner or later there will be a nasty note from post waiting...
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Auto gain is the last option in the world. The DVX sports an automatic limiting feature rather than auto gain, which can help protect against sudden peaks, but if you are using a camera that has AGC rather than ALC, avoid it like the plague. The purpose of AGC (automatic gain control) is to keep the audio as close to the reference point as possible, with as little dynamic range as possible. It ends up making the audio sound like it's been run through a really bad compression circuit... because, essentially, it has.
 
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When the distortion goes away, where are you turning it down from? Are you turning down the speaker amplifier or the input level of your mixer? There is 101 ways to distort your signal after you recorded it.
 
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