FORUMS: list search recent posts

Buzz/Hum

COW Forums : Audio Professionals

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
Pat Ford
Buzz/Hum
on Apr 5, 2007 at 6:46:44 pm

So I'm doing a documentary; did an interview last night. I was
sidetracked dealing with the subject until several minutes into the
interview when I noticed that the camera operator did not have his
headphones on. At that point we discovered that we had a significant
buzz. The subject was antsy so we went ahead with the interview.

All of the above was my fault but now I am left with the chore of
eliminating or at least lessening the buzz.
I have Sound Forge 6, but am not very skilled to say the least. I have
tried notch filters but it does not seem to have any effect at all.

Here is a .wav example of the footage;
http://www.criterionweb.com/stevetalkrepair.wav
It is about 10 megs. If you would download it and comment I assure you
will qualify for sainthood.

Thanks.


Return to posts index

Will Salley
Re: Buzz/Hum
on Apr 6, 2007 at 3:46:43 pm

I was able to get rid of most of the buzz by using the noise print / reduce noise filter in Soundtrack Pro. The only adjustment I made from the default settings was to put the thresho;d at -52 db. The Soundtrack Pro software comes in the Final Cut Studio bundle but it is, by no means, the only app that can do this.

You can listen here( 9.6MB):

http://www.auralondesign.com/stevetalkrepair.wav





System Info - G5/Dual 2 - 10.4.8 - QT v7.1.3 - 8GB ram - Radeon 9800Pro - External SATA Raid - Decklink Extreme - Wacom 6x8



Return to posts index

Steve Wargo
Re: Buzz/Hum
on Apr 7, 2007 at 5:27:31 am

First of all, don't ever record ANYTHING without monitoring the record device, both audio and video. I hope you can fix your present problem but make sure that you never forget what happened here. I learned this lesson the hard way 20 years ago and I never start a session without thinking about that one time.

Even though your talent was antsy, as a professional, you must take the time to fix the problem before you shoot. A professional makeup artist has bailed us out on numerous occasions when we've had a last minute disaster. She will jump in and tell the camera crew that she needs a minute or two to adjust a shiny spot, adjust a collar, put some hair in place or something, just to burn a few minutes. It seems like the CEOs will wait a minute for a lady when they're all over us guys to "get it done". A knowledgable, experience make up artist can save your butt.

As for the camera guy with no headphones, find someone else. Not wearing headphones is like shooting with no monitor.

Steve Wargo
Tempe, Arizona

It's a dry heat!


Return to posts index


Pat Ford
Re: Buzz/Hum
on Apr 7, 2007 at 5:44:08 pm

If Mr. Wango had read my post he might have noticed that I said:

"So I'm doing a documentary; did an interview last night. I was
sidetracked dealing with the subject until several minutes into the
interview when I noticed that the camera operator did not have his
headphones on. At that point we discovered that we had a significant
buzz. The subject was antsy so we went ahead with the interview.

All of the above was my fault."

I wanted suggestions for solving the problem. Instead, Mr. Wango demonstrates his eye for the obvious.


Return to posts index

Ty Ford
Re: Buzz/Hum
on Apr 8, 2007 at 3:52:33 am

Hi Pat,

It's important to remember that many people read this forum. Problems associated with not listening to the audio as it's being recorded are, unfortunately, very common. We get at least one "confession" a month. Some seem not to understand that the answer to when to listen is ALWAYS. Thanks for sharing your experience and helping to remind others that listening is important.

I was on a shoot friday and for some weird reason, in the hour long presentation, at one point there was a small drop out. Weird. Never heard anythinig like it. I wasn't listening to playback, but I was listening to the headphone jack, back through my snake to my mixer where my headphones were plugged in. Had I not been listening, (always), I wouldn't have heard it. I flagged the shooter. We cut and redid that part.

Breaking the action to fix a techical problem freaks some people out for some reason. It's much better to stop and fix things than shut up and wait for it to show up in post.

The makeup gal routine is exceptional and shows she was a real team player.

Regards,

Ty Ford


Ty Ford's "Audio Bootcamp Field Guide" was written for video people who want better audio. Find out more at http://home.comcast.net/~tyreeford/AudioBootcamp.html
or http://www.tyford.com
Download Ty Ford's "Existential Boogie" from iTunes now.


Return to posts index

Steve Wargo
Re: Buzz/Hum
on Apr 8, 2007 at 4:29:30 am

Thanks Ty

It seems like Pat Ford is a new guy on the block and does not understand that your eyes stay plastered to the monitor and that headphones are to be worn every second that recording is in progress. He also seems to miss the point that the way to avoid fixing the problem is to avoid having it happen in the first place. We've all had the unfortunate happen and if we have a way to repeat something, we do.

In 2005, we shot an HDCAM segment for a TV show, at a nature conservatory in Flagstaff Arizona with Senator John McCain. When we were done and the Senator had moved on, my audio guy tells me that there were a bunch of dropouts during the interview on the Senators wireless. When I asked him why he didn't say anything, he said that he didn't want to interrupt. So, he doesn't interrupt and I have no sound. We had to pull it all from the other persons mic. It sucked. I didn't wear headphones that day because I was taking cues from the producer. Lesson learned again.

My reply, Pat, was aimed at your future, not your past.

Steve Wargo
Tempe, Arizona

It's a dry heat!


Return to posts index


Pat Ford
Re: Buzz/Hum
on Apr 8, 2007 at 7:54:06 pm

Hello Ty,

Our paths have crossed before, on rec.video.production, if memory serves. One of the greatest benefits of the internet is the ability to summon expertise on a specialized subject. I do this all the time on various forums and well as USENET.

Since I first went online in 1994, I can hardly be considered a bumpkin that just fell off the turnip truck in the online world. On USENET and forums, I ask questions without regard to lost pride or possible embarrassment. Most of the time my answers are generously answered. It is really amazing. Typically I will get a range of answers; I will then check out the various answers comport with what I know


Return to posts index

Vincent Becquiot
Re: Buzz/Hum
on Apr 8, 2007 at 10:34:00 pm

Hey,

Not much more to offer than what you've tried to fix the problem.

For future productions:

Did you separate power and "the rest" of the equipment? (I mean on a completely separate breaker?), and did the rest of your equipment have a common ground? Audio on the same circuit as dimmed lighting will almost always hum. Finally, groundlifts (on everything except lighting) can also be a lifesaver.

If you did separate everything, then theorically you should be hum free, even crossing power. If not, you may have a shielding problem on your XLR (assuming that's what you used).

Sorry if all of this sounds obvious, but I see many, many people ignoring that simple rule.

Glad you were able to take care of the issue.

Cheers,

Vince



Return to posts index

Pat Ford
Re: Buzz/Hum
on Apr 9, 2007 at 1:45:57 am

[Vincent Becquiot] "Did you separate power and "the rest" of the equipment? (I mean on a completely separate breaker?), and did the rest of your equipment have a common ground? Audio on the same circuit as dimmed lighting will almost always hum. Finally, groundlifts (on everything except lighting) can also be a lifesaver.

If you did separate everything, then theorically you should be hum free, even crossing power. If not, you may have a shielding problem on your XLR (assuming that's what you used)."


Thanks for your advice.

Well, the place was an old building. The floors were out of level...almost like scenes from the Cabinet of Dr. Caligari. We could find only one grounded outlet. (!)

We were using XLRs, but the mic was on a mini-plug.

We will try to follow your advice in the future. Thanks again.


Return to posts index


Ty Ford
Re: Buzz/Hum
on Apr 9, 2007 at 12:26:06 pm

----We were using XLRs, but the mic was on a mini-plug.---

That in itself could have been the problem.

What mic, what camera, what cable?

Regards,

Ty

Ty Ford's "Audio Bootcamp Field Guide" was written for video people who want better audio. Find out more at http://home.comcast.net/~tyreeford/AudioBootcamp.html
or http://www.tyford.com
Download Ty Ford's "Existential Boogie" from iTunes now.


Return to posts index

Pat Ford
Re: Buzz/Hum
on Apr 9, 2007 at 2:54:44 pm

[Ty Ford] "----We were using XLRs, but the mic was on a mini-plug.---

That in itself could have been the problem.

What mic, what camera, what cable?"


Ty, I mentioned some of this a couple posts back up the thread.

Inexpensive lavalier with minijack > XLR cable > PD150. The minijack cable picked up hum from dimmer. The camera had noise reduction on, which introduced problems of its own.



Return to posts index

Ty Ford
Re: Buzz/Hum
on Apr 9, 2007 at 3:44:55 pm

Pat,

Sorry. Mics usually don't have jacks, they have plugs. I don't want to be a nomenclature nazi, but terms are important.

So the mic had a mini-plug of some sort? The problem was very likely the connection between the mic plug and the female XLR connector on the cable. You must have used some sort of adapter. What kind?
Regards,

Ty



Ty Ford's "Audio Bootcamp Field Guide" was written for video people who want better audio. Find out more at http://home.comcast.net/~tyreeford/AudioBootcamp.html
or http://www.tyford.com
Download Ty Ford's "Existential Boogie" from iTunes now.


Return to posts index


Pat Ford
Re: Buzz/Hum
on Apr 9, 2007 at 4:03:00 pm

[Ty Ford] "So the mic had a mini-plug of some sort? The problem was very likely the connection between the mic plug and the female XLR connector on the cable. You must have used some sort of adapter. What kind?
Regards,

Ty"


Ty,

Yes, there was a mini-plug/XLR adapter.

But as I mentioned above in another post, the noise was caused by the dimmer acting on the mini-plug cord.

Thanks for the help. The problem has been solved.



Return to posts index

Bob Cole
May your only buzz come from a bottle... or a can.
on Apr 14, 2007 at 2:59:03 am

[Pat Ford] "the noise was caused by the dimmer acting on the mini-plug cord."

You folks probably already know about this one, but in the spirit of sharing, I've had another problem with dimmers (and I think my dimmers are pretty well-made, by Magic Gadgets).

I got a buzz from using a dimmer, even with balanced ables, isolating the light fixtures' wires from the mic cables, camera on battery.... I even changed audio to wireless, before I realized I was hearing the dimmed filament in the lighting instrument. So I changed bulbs -- no difference. My particular lamps wanted all power or nothing.

There are lots of alternatives to outboard dimmers: scrims, added diffusion, moving the light back, or, best of all, using dimmable fluorescents (Kino Diva, in my case) instead of tungsten.

-- Bob C


Return to posts index

Pat Ford
Re: May your only buzz come from a bottle... or a can.
on Apr 14, 2007 at 4:00:03 am

Bob-

Good point...it's hard to try to outsmart physics. One of the problems was that we were shooting in a tiny room. Next time I may rent a theater...that might solve several problems. Thanks.

pcf


Return to posts index


Steve Wargo
Re: Buzz/Hum
on Apr 10, 2007 at 4:59:54 am

So Pat, go back and read your post. Certainly looks like a couple of new guys to me. Whether you are or aren't, your original post smacked of newby. Have a nice day and don't forget to wear those headphones.

Steve Wargo
Tempe, Arizona

It's a dry heat!


Return to posts index

Ty Ford
Re: Buzz/Hum
on Apr 10, 2007 at 7:05:03 am

Steve, Pat,

Apparently there's some unfinished business between you that should be settled somewhere other than this forum. Hope it works out for both of you.

Thanks,

Ty Ford


Ty Ford's "Audio Bootcamp Field Guide" was written for video people who want better audio. Find out more at http://home.comcast.net/~tyreeford/AudioBootcamp.html
or http://www.tyford.com
Download Ty Ford's "Existential Boogie" from iTunes now.


Return to posts index

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
© 2017 CreativeCOW.net All Rights Reserved
[TOP]