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-   -   Avoid Clipping While Recording A Marching Band? (https://www.dvinfo.net/forum/all-things-audio/111198-avoid-clipping-while-recording-marching-band.html)

Glenn Fisher December 29th, 2007 10:14 PM

Avoid Clipping While Recording A Marching Band?
 
I'm a high school student and fairly new to audio and video production. Throughout the last few months, I've been recording my school's award winning marching band with a Sony HDR-HC1 and a camera-mounted Rode Videomic. Looking back at the footage that I recorded, using the camera's built in automatic level-adjustment seemed to cause a lot of the footage that I shot of them in the stands (the mic was very close to the band at these times) to clip and become slightly distorted.

I'm trying to avoid this for what I film in the future. What is the best way to keep from clipping? I tried setting my audio controls to manual, but with the band, I seem to remember very dynamic volumes. At times they would be -20 dB, then almost clip when they got louder.

I read somewhere that a field recorder might help solve some of these issues (and probably also provide me with more control over the levels, I'm not a huge fan of the HDR-HC1's audio controls) and so I've been looking at the H2 and H4 from Zoom (trying to keep the budget fairly low, I am only a student after all) but I've read about their sync problems. Could that be an issue when recording a practice and framing a drummer or a student playing the vibraphone, and if so, is there any easy way to fix that? (It seems like having to break up the audio into separate clips in post and line each one up would be a pain, and I'm not sure what I would do with any audio that overlaps).

Thanks for your help! It's much appreciated!

Andy Wilkinson December 29th, 2007 10:31 PM

HC1/Videomic/H2 and Clipping
 
Hi Glenn and welcome!

I have all of the above gear. Yes, audio controls on Sony HC1 are pretty limited (and the highly compressed audio used in HDV format is not brilliant anyway.) The Videomic is quite hot also. So your possible solutions are as you state, run the audio level in manual not auto on the HC1 or use some thing like the Zoom H2.

The Zoom H2 will allow you to set levels more precisely (and if wanted has AGC or limiters but I find these a bit "severe".) Also, the 24 bit recording option will give you a little more breathing space for dynamic/challlenging music recording too - then convert to 16 bit if needed (although most if not all NLE's handle 24 Bit now.)

Don't worry about the slight syncing issues between sound and video as these are very easily fixed in post in your NLE - any small "gaps" in audio can be filled in with wild sound (ambient noise) or, often more easily, you can use the velocity envelopes in NLE's like Vegas to adjust video or audio to match portions exactly.

I'm no expert (but trying to get there!) Hope this helps!

Anna Harmon December 30th, 2007 04:20 PM

If you're going to use the H2 use external mics. The internal mics pick up handling noise which will ruin your audio.

Chris Leong December 30th, 2007 04:28 PM

Glenn
I have an HC1 as well and when audio is important I use a Beachtek DX-8a with a dedicated mic pre per channel, phantom power and a limiter each channel. This actually yields really excellent sound quality.
If you're shooting mic on camera then you have to get an isolation (rubber band type) mount for your camcorder. If you bump the camera the noise won't be picked up by the mic. A windscreen helps outdoors as well.
I'm a fan of Sony Mid-Side electret mics for that you're shooting, but I know that many people aren't.
The Rode is an okay mic but you have to check and maybe change the iso mount. That with a decent mic pre (like one of the lower end Beachteks) and limiters should result in a package that's still fairly light and mobile but with much higher quality audio.

There is really no substitute to a decent sound guy with a boom pole mounted mic, though. Otherwise they'd all be out of work. And as you may know, none of them are.

Anna Harmon December 30th, 2007 05:17 PM

Chris, he's a kid. No reason for him to hire someone to record his school marching band for the school. There's no budget for sound unless he gets one of his buddies to chip in and do sound and maybe see what he could use from the AV department.

Chris Leong December 30th, 2007 05:39 PM

Hey Anna
Funny thing about films and movies - nobody cares how old the makers are, or what nationality they are, or how much money they didn't have, or how fast they shot it, or what they didn't spend.

If you get something made, people will watch it and they won't care.
I turned down my first French Vogue cover at 19. That's 'cause they wouldn't pay me, and I'd just shot something for Vogue italia men's the month before with pay.

That hasn't changed much either.

I didn't say that the boom op had to be a pro , I said that good audio guys are still essential to a shoot with good audio. If they weren't, there would be no audio department on films and people would be shooting with camera mounted shotguns or wireless packs all the time. But no, there's still this archaic guy with this old fishing pole still stuck out there on location. Why? Because of the high technology? Not.

So get a guy who's technically minded, at least moderately physically fit, not a midget, preferably has an ear for music, and have him or her read this:
Hi -
get a painting pole from Home Depot and kluge the Rode mic onto that. Experiment with hard and soft mounts, tape, string, etc.
Then get the mic pointed in the right direction and close up. Then get some headphones and really listen. Concentrate on just the audio and fiddle with direction and controls. Better? Worse? Put the mic back on the camera. Better? Worse?

Mic theory is relatively easy - think of a shower head. The water sprinkles out of the shower hear, right? Now think of it in reverse. The water going into the shower head. That's sound going into a mic. Could be set narrow spray (shotgun) or wide. You get the idea.

Most movie makers use hypercardiod shotgun style mics. People tend to think that those mics pick up only what they're aimed at.
Well, yes and no.
Even a shotgun mic isn't like a rifle, it doesn't have a pickup area of a dime at a hundred yards. No, it's more like that reverse shower head. So it will pick up whatever water (sound) it's pointed at. Which is why a boom is still used, because the ground, especially with a carpet on it, is usually the deadest sounding background to have. i.e. you want the mic above the talker and pointing down at the ground. et voila - enter the mic boom.

Except now, when the actors move, then the mic has to move too. Or if they march, so must the boom op. Or Run. And keep the boom and its shadow out of shot...
and now the fun begins, and we're beyond mic theory 101.
and getting into the pro realm. Especially since the rule of filmmaking applies. Nobody cares if the sound op is 6 or 60, as long as the sound is clean and clear, and the mic and boom is out of shot.

My kid of 6 can do it, for a single shot. I wouldn't ask him to do it for more than that. To get it all right, every shot, day after day, that's what you pay a pro for.
But you don't have to be a pro to get it as right as you can with what you've got.
I started in this business, in the industry, at 15. But I had been playing around with cameras and sound since much before then, maybe 12 or so. I won my first state open piano competition at age 7.
Like I said. Nobody cares, as long as it's good.

One of the best things Glenn done is to ask that question on this thread. That's not kid stuff, not by any means.

Michael Nistler December 30th, 2007 07:01 PM

Hi Glen,

FYI - if you have an extra microphone, you might try recording on both channels in manual gain mode with one channel set with 20dB stronger than the other channel. Set the "hotter" channel so it almost clips with normal signal strength and the "colder" channel so it's 20dB lower. Then in post, use your audio editor to look for clipping spots (visually flat tops about 0dB) on the hot channel, pasting non-clipped audio from the other channel (normalizing audio).

Good luck, Michael

Chris Leong December 30th, 2007 07:08 PM

Great idea -- most people use this for dialog only. 'cause you're ending up with only one good (usable) track.

For a band, however, you'd probably want to stay in stereo.

If your post is to be done in Final Cut, then Soundtracks Pro has a wonderful de-peaking device that can recover some of the audio from a blown out track. However, this is mainly a defensive move. Mostly it's best to have someone just concentrating on getting good sound.

If push came to shove and you HAD to just shoot it with no help, I'd probably use Michael's method, and live with mono music if I were you.

Or do some pretty fancy audio editing and only to go double mono when the loud track got too loud...

Of course, this also isn't kid stuff. But it is a very good way to go.

David Ennis January 2nd, 2008 08:06 PM

I agree with what Chris has said, but I also acknowledge the principle of diminishing returns. The closer you get to obtaining the best possible audio in a given situation, the more the next incremental improvement tends to cost in terms of money and effort. I think that this was the gist Anna's comment.

And meanwhile, for every one audiophile among the viewers of a school video there are 500 moms, dads and grandparents who are oblivious to differences in sound quality above the level that the man on the street would call decent. So the intended audience is a consideration. Glenn pretty much implied that he was happy with the audio for now except for the clipping, and got some good advice on that.

Steve House January 3rd, 2008 06:26 AM

Quote:

Originally Posted by David Ennis (Post 801643)
....
And meanwhile, for every one audiophile among the viewers of a school video there are 500 moms, dads and grandparents who are oblivious to differences in sound quality above the level that the man on the street would call decent. So the intended audience is a consideration. Glenn pretty much implied that he was happy with the audio for now except for the clipping, and got some good advice on that.


I have to disagree. Nowdays everyone has a stereo, a television, goes to movie theatres. The audience has been trained by a lifetime of listening to professionally produced sound to know what it CAN sound like even if they can't articulate how it got there or what's wrong with it when it doesn't make it. They've been trained to consider what they hear on the soundtrack of, say, "CSI-Miami" as the norm and they're not mistaken - when you hear it 8 hours per day for 40 years, it IS the norm. If you're shooting for other than personal pleasure, your clients are going to demand that level of quality of recording as the minimum level to be considered acceptable professional work (if you hope to get repeat business at any rate).

Chris Leong January 3rd, 2008 07:36 AM

It goes without saying that even the youngster who posted this understands what clipping is, and knows what it sounds like.

So - is that kid's stuff?

It can be, if one wishes to be patronized and condescended to.
(Poor kid, better luck next time... Don't worry, you've got a lifetime to get it right, Why don't you leave this to the pros and go back to school, yadda yadda -- BTDT got the t shirt.)

If not, there's clipped audio, and not clipped audio. Stereo audio and mono. Simple stuff.

Most everybody can hear and tell the difference, even if they don't know exactly how to put a finger on what that difference is.

Don't want to write another novel here, but take it from me. (I can prove it if you want.)
Almost everybody (save deaf and tone deaf people) can tell the difference.
For sure.

David Ennis January 3rd, 2008 08:57 PM

Quote:

Originally Posted by Steve House (Post 801860)
I have to disagree. Nowdays everyone has a stereo, a television, goes to movie theatres. The audience has been trained by a lifetime of listening to professionally produced sound to know what it CAN sound like even if they can't articulate how it got there or what's wrong with it when it doesn't make it. They've been trained to consider what they hear on the soundtrack of, say, "CSI-Miami" as the norm and they're not mistaken - when you hear it 8 hours per day for 40 years, it IS the norm. ...

Ironically, Steve, you're echoing a post I made here several years ago: http://www.dvinfo.net/conf/showthrea...hlight=trained
--and I still stand by that. But this context is different. Glenn's marching band audio is in an entirely different arena than dialog audio, which was the subject of my old post.
Quote:

Originally Posted by Steve House (Post 801860)
... If you're shooting for other than personal pleasure, your clients are going to demand that level of quality of recording as the minimum level to be considered acceptable professional work (if you hope to get repeat business at any rate).

True--allowing again for the differences in expectations between music and dialog--but Glenn never said he was being paid or had clients or was in business. Meanwhile he was explicit about "trying to keep the budget fairly low."

I didn't say and will never say that crappy audio doesn't distract everyone from enjoying a video. But when you get to the level of "decent" audio and above, the situation changes. The overwhelming majority of people viewing a video for the chance to see their sons or granddaughters or friends march by are, indeed, oblivious to the fine points of the audio.

And Chris, "oblivious" does not mean incapable of hearing the difference. Look it up.

Yes, this is an audio forum, and and a lot of us care about audio, know a lot about audio and, let's face it, kinda want everyone know we know. But let's not automatically respond to every post with the same blunt admonition to spend everything they've got and more on audio or settle for being a hack. People coming here with questions or looking for advice are speaking from a great variety of situations.

Chris Leong January 3rd, 2008 09:12 PM

David
While I agree with your post in principle, what I was speaking about was what you were referring to as 'crappy audio', and not much higher than that, not in this situation.

I also agree that the entire thrust of this thread was to get usable audio - i.e. not pristine professional level audio, just usable audio above the 'crappy' level.

For a beginner, this is quite a feat in itself, and requires due attention to detail.

This probably means dedicating someone who is smart to do the job of watching the meters, instead of having one beginner try to do the job of two.

That's it.

Steve House January 4th, 2008 07:15 AM

Chris & David

Didn't mean to suggest that a high school student shooting his school's marching band should go out and blow his college fund on high-end audio gear <grin>. But I am assuming the video he's shooting will be used for something other than just his own personal video scrapbook. And when he starts to distribute it to other people, they're going to be viewing it with the same quality mindset they view broadcast television. As such, the objective becomes more than just avoiding 'crappy sound' but rather how good can one get it given the limitations of time and budget within which he has to work. It's a subtle attitude-shift to go from "I don't want it to sound bad" to "I want it to sound as good as I can get it."

Jack Walker January 4th, 2008 02:06 PM

This current thread seems to be on the same subject:
http://www.dvinfo.net/conf/showthread.php?t=111568

The post toward the bottom has some good instructions on using the Rode Videomic when recording a band.

Where is the band being recorded? In a band rehearsal room? Outside? Marching? Standing on a football field?

In general, I think marching bands are very difficult to record to get a good sound.

On top of that, a mic on a video camera is not going to be in the right place to get much of anything, especially if you are getting any interesting video shots.

I think the recording of the music and videotaping should be separate. Use the video sound for reference and possible closeup ambience when the band is not playing, or even maybe some stomping sounds to mix in, etc.

Get a small recorder of some sort and go out with the band for rehearsal. Try different things. Put the mic on a poll over the band. Put a wireless lave (with windshield) on the top of the had of the conductor. Use two mics separated and up in the air and reocrd in stereo.

You can also record the band in rehearsal, standing still, then put this music with your video. The band will play almost exactly the same tempo and with cutting small adjustments can be made to resynch through the edit.

It seems there are two different kinds of videotaping you might be doing.

First, made a record of the band and it's routines (typical videographer stuff) where the quality of the sound is not that important.

Second, show off the band in a kind of music video. In this case you want to get the sound separate from the video, and do the best you can to get good sound. Then get video, probably more than one performance or dress rehearsal, and cut it together to the sound.

If you are our running around alone with a video camera and a mic on top, you will be lifmited. (But see other thread for clipping problem.)

If you are doing a project, there are many possible ways to look at the situation and many options are possible with high school students.


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