Noise situation for a documentary at DVinfo.net

Go Back   DV Info Net > The Tools of DV and HD Production > All Things Audio

All Things Audio
Everything Audio, from acquisition to postproduction.


Reply
 
Thread Tools Search this Thread
Old July 30th, 2007, 07:54 AM   #1
Major Player
 
Join Date: May 2006
Location: Boston, Massachusetts
Posts: 425
Noise situation for a documentary

Hi-
I recently worked on a documentary where we rented a hotel room to film some interviews. The producer went to the hotel room the day before. The room was a meeting room, and totally quiet. Great location, yes?

Well, the day of the filming, the air conditioning is roaring. At least, the hotel people told us the sound was air conditioning. It was very loud. It never went off the whole day.

We knew the sound was going to be effected, but we didn't have another location to go to, and cancelling all the interviews that day wasn't a good option.

The hotel folks didn't have another room to move us to (I think the AC was running in all of them anyway) and also refused to turn off the A/C.

So we recorded as planned, and we're going to try and clean up the sound as best we can.

No one reading this knows how loud the sound was, but I'm wondering if other people would have made the same call? Would you have said 'If the sound is going to be bad, then we're wasting our time. Film somewhere
else, or cancel for the day'?

We didn't have a mixer, would that have been helpful in such a situation?

If not for the AC, the place would have been perfect. Do other people film in hotels and do you ask if you can turn off the AC when needed?
Dennis Stevens is offline   Reply With Quote
Old July 30th, 2007, 09:41 AM   #2
Major Player
 
Join Date: May 2007
Location: Toronto, Ontario, Canada
Posts: 287
...I often have to shoot interviews in offices where it's impossible to turn the AC off, so I try to minimize the AC noise through careful mic'ing.
( a good set of headphones will give you some idea of how bad the noise really is )

Can you post a small sample of the audio you recorded?
( I'm curious to see how much it can be cleaned up with software )
Guy McLoughlin is offline   Reply With Quote
Old July 30th, 2007, 09:44 AM   #3
 
Join Date: Jan 2004
Location: Stockton, UT
Posts: 5,648
1. Plan the site better. You can sometimes find hotels that will work with you, but it is definitely rare.
2. Record with a good level. A low level will kill you in post.
3. WAVES, BIAS, Sony all have great noise reduction tools. Audition/SoundBooth have pretty good NR tools. If the AC is constant, you can usually bring it to a useful level, but you'd obviously have been better off w/out it.
Small budget in production usually means bigger budget in post.

A mixer might have helped in the decision process, but noise is noise. Either you find a way to deal with it or you don't shoot, IMO. The whole concept of "We'll fix it in post" is BS most of the time, again...IMO.
__________________
Douglas Spotted Eagle/Spot
Author, producer, composer
Certified Sony Vegas Trainer
http://www.vasst.com
Douglas Spotted Eagle is offline   Reply With Quote
Old July 30th, 2007, 09:48 AM   #4
Major Player
 
Join Date: May 2006
Location: Boston, Massachusetts
Posts: 425
Quote:
Originally Posted by Guy McLoughlin View Post
...I often have to shoot interviews in offices where it's impossible to turn the AC off, so I try to minimize the AC noise through careful mic'ing.
( a good set of headphones will give you some idea of how bad the noise really is )

Can you post a small sample of the audio you recorded?
( I'm curious to see how much it can be cleaned up with software )
Yeah, that's a good point. We tried to get the mics as close as possible, but maybe there was more to be done. We were trying to get a sound person at the last minute, but couldn't. I do alright when conditions are not too terrible, but I'm no professional sound recordist.

I can put up a sample, it will be a few hours from now, as I'm not near the equipment right now. Thanks for your offer.
Dennis Stevens is offline   Reply With Quote
Old July 30th, 2007, 09:54 AM   #5
Major Player
 
Join Date: May 2006
Location: Boston, Massachusetts
Posts: 425
Quote:
Originally Posted by Douglas Spotted Eagle View Post
1. Plan the site better. You can sometimes find hotels that will work with you, but it is definitely rare.
2. Record with a good level. A low level will kill you in post.
3. WAVES, BIAS, Sony all have great noise reduction tools. Audition/SoundBooth have pretty good NR tools. If the AC is constant, you can usually bring it to a useful level, but you'd obviously have been better off w/out it.
Small budget in production usually means bigger budget in post.
Thanks - I'm thinking from now on, we will at least ask a hotel (or wherever we are recording) if we can control the thermostat or AC. But it seems like a lot of places do not have that option.

At least one of the speakers I think we got good levels, but they could have been better.

The only 'plus', if it can be called that, is that the AC is constant - boy is it constant.
Dennis Stevens is offline   Reply With Quote
Old July 30th, 2007, 10:06 AM   #6
Major Player
 
Join Date: May 2007
Location: Toronto, Ontario, Canada
Posts: 287
Quote:
Originally Posted by Dennis Stevens View Post
I can put up a sample, it will be a few hours from now, as I'm not near the equipment right now. Thanks for your offer.
If you can, try to include a sample of just the AC by itself ( no one is talking for a few seconds ), which will make it easier to determine how to filter it out.
Guy McLoughlin is offline   Reply With Quote
Old July 30th, 2007, 10:10 AM   #7
Inner Circle
 
Join Date: Sep 2002
Location: San Mateo, CA
Posts: 3,840
Aside from getting the best sound possible in production (IE: A dedicated sound recordist monitoring the set) - getting the mics close, possibly using a bass roll-off depending on the quality of the noise - all you can hope for is to get the system turned off.

Most systems in large building are controlled by a central thermostat, and that's why they are loathe to sacrifice the air in other rooms to accomodate your room.

If you can't get the system turned off , you CAN do a few things to dampen it on site. There are two sources for AC noise - mechanical and airflow.

The mechanical sound - the sound of the ac compressor clicking on or the fan running, is usually generated from another room, or from a rooftop above. It reaches the room through vibrations in the wall and ac ducts. Not much can be done to minimize that sound.

The sound of the AIRFLOW - that is the sound of air hissing through the grates/vents can be mitigated in a number of fashions. IF you can adjust the vent, try that first. CLOSING the vent completely can silense the airflow, but only if you can close it completely. (This might have the added bonus of eliminating some of the mechanical noise that might be channeled up the vents.) Most vents won't close completely however, and by minimizing the airflow, you might actually increase the 'hiss'. SO try OPENING it completely.

Point is, adjust it for most silent operation. Also consider BLOCKING the airflow with furni-pads. Every good grip kit should have one or two. I've used furniture pads dangeling in front of ac vents or refrigerators that couldn't be turned off before. It helps some, and as Douglas points out, anything you can do in production is going to save you time and money in post.
Richard Alvarez is offline   Reply With Quote
Old July 30th, 2007, 11:17 AM   #8
Major Player
 
Join Date: May 2006
Location: Boston, Massachusetts
Posts: 425
Thanks for everyone's suggestions. We've taped a couple of interviews in office-like situations, and we've never had this much of a problem with background noise.

Richard's tips on dealing AC are very good, me thinks.
Dennis Stevens is offline   Reply With Quote
Old July 30th, 2007, 11:25 AM   #9
Major Player
 
Join Date: Aug 2006
Location: Columbus, Ohio
Posts: 423
Quick question - sort of on topic, sort of not -

Just furniture pads that you would buy from a moving company or are there specific sound reduction blankets available?

Thanks,
Kevin
__________________
"... the drama is on your doorstep..." - John Grierson
www.grvideo.net
Kevin Randolph is offline   Reply With Quote
Old July 30th, 2007, 11:58 AM   #10
Inner Circle
 
Join Date: Mar 2005
Location: Hamilton, Ontario, Canada
Posts: 5,742
Quote:
Originally Posted by Kevin Randolph View Post
Quick question - sort of on topic, sort of not -

Just furniture pads that you would buy from a moving company or are there specific sound reduction blankets available?

Thanks,
Kevin
You can get special sound blankets but regular furniture pads work just as well, just maybe not as glamorous, and a LOT cheaper.
__________________
Good news, Cousins! This week's chocolate ration is 15 grams!
Steve House is offline   Reply With Quote
Old July 30th, 2007, 04:14 PM   #11
Major Player
 
Join Date: Aug 2006
Location: Columbus, Ohio
Posts: 423
I've never been glamorous... ;)
__________________
"... the drama is on your doorstep..." - John Grierson
www.grvideo.net
Kevin Randolph is offline   Reply With Quote
Old July 30th, 2007, 04:56 PM   #12
Inner Circle
 
Join Date: Sep 2002
Location: San Mateo, CA
Posts: 3,840
... and I've always been cheap. But that doesn't mean I'm EASY!!

FurniPads are a staple in grip kits. Mostly for protecting surfaces just like movers do. Lots of times you want to cover furniture in locations if you have to haul equipment around. ESPECIALLY if you don't own the nice furniture and you want to shoot there again. And yes, they can double as sound baffles, and stunt pads, and sleeping pallets and ... well, never mind.
Richard Alvarez is offline   Reply With Quote
Old July 30th, 2007, 08:58 PM   #13
Inner Circle
 
Join Date: Feb 2006
Location: Los Angeles, California
Posts: 2,069
Please!

Hi Dennis:

Please tell me that you were a smart boy and recorded with a lav and a boom as everyone should everytime possible?

If you did, you should find that the lav will have a LOT less of the offending noise than the boom.

Personally, I use SoundSoap Pro from Bias, it's pretty good although the WAVES Restoration bundle is better. Neither will completely eliminate your noise but both can bring it down to a tolerable level. Will your interviews have music behind them? Musc, even low in the mix, can mask a lot of ambient noise.

If you only recorded with a boom, you are learning a painful lesson. ALWAYS mic interviews with both boom and lav. More often than not, the lav will save your rear in these situations.

BTW, I shoot interviews in hotel rooms all of the time, not to mention at offices at the movie studios where the AC controls the whole floor so it cannot be shut off. This is a common problem. Some extra C-stands and sound blankets/furni pads would have saved your rear, learn from that and next time bring them.

We've all been where you are, best of luck,

Dan
Dan Brockett is offline   Reply With Quote
Old July 31st, 2007, 08:24 AM   #14
Regular Crew
 
Join Date: Apr 2007
Location: Olney, Maryland
Posts: 197
Don't expect sound blankets to work miracles either...they are NOT broad band absorbers. They do not provide any isolation from low frequency mechanical noise.

Always record :30 of room tone at the end of the shoot for having the ability to use noise reduction software to lower the offending noise.
Jim Boda is offline   Reply With Quote
Old July 31st, 2007, 08:45 AM   #15
Major Player
 
Join Date: Jun 2005
Location: West Point, MS
Posts: 313
On several occassions I have been involved in recording interviews with a constant noise wether it be a air conditioner or a furnace or refrigrator. One thing I always consider is what is the subject matter of my story. On several occassions I have looked for a sound that will drowned out the constant annoying sound and also fit in with my subject matter. In one instance the air conditioner was non stop and we moved our talent over to the window and opened the window so we could here the traffic in the background instead of the air conditioner. We placed a hypercardoid 5 inches from the talent facing away from the traffic and placed a omni directional toward the traffic. Mixing the 2 together gave the interview a great quality that fit the story and the traffic noise was very much like the score to the piece. There have been times we have used a bird feeder(birds chirping), water running, television, radio, and also train rumbling. It works fairly well if the mix is unintrusive to the words being spoken.
John M. McCloskey is offline   Reply
Reply

DV Info Net refers all where-to-buy and where-to-rent questions exclusively to these trusted full line dealers and rental houses...

Professional Video
(800) 833-4801
Portland, OR

B&H Photo Video
(866) 521-7381
New York, NY

Z.G.C.
(973) 335-4460
Mountain Lakes, NJ

Abel Cine Tech
(888) 700-4416
N.Y. NY & L.A. CA

Precision Camera
(800) 677-1023
Austin, TX

DV Info Net also encourages you to support local businesses and buy from an authorized dealer in your neighborhood.
  You are here: DV Info Net > The Tools of DV and HD Production > All Things Audio

Thread Tools Search this Thread
Search this Thread:

Advanced Search

 



Google
 

All times are GMT -6. The time now is 02:34 AM.


DV Info Net -- Real Names, Real People, Real Info!
1998-2017 The Digital Video Information Network