Sound insulation at DVinfo.net

Betsy Moore · May 17th, 2004, 04:23 PM

We're shooting a no-budget hd movie set in a cabin in the mountains but the set is actually a redecorated apartment in Los Angeles. We're using a Senheisser Me66 shotgun mic for most of the audio. Unfortunately, even with all the windows closed we're still getting a little bit of street noise. We don't have the money, time, or expertise to rely on fixing it in post. I was wondering if anyone had advice on what kind of clear temporary insulation we could put on the windows, like putting up a big thick plasti, glass, plexiglass pane and resting it on the window sil. To make matters worse we're using the windows as a light source so we can't cover them completely (though we have covered them with fake frost/snow)--and we're going to be shooting in a non-airconditioned apartment on the east side in the early summer--with all the actors wearing winter clothes--so taking the insulation down and opening the windows between takes is a must unless we want to shoot a movie about fainting.

Does anyone have any advice about what we could put up and how we could put it up and where we could get it?

Thanks

Christopher C. Murphy · May 17th, 2004, 06:34 PM

Suggestion, if it's a short scene and you can get away with it...put a television on and show it when the scene starts. Record a fake "movie" that takes place in the streets, so people watching your movie will accept the noise in the room.

It may not work in your scene if you are in a remote cabin and it's for a long time. But, maybe something similar might work? How about a radio in the background that adds some white noise, so you can cover up the street?

Another idea is to "record" the sound of room with no one talking or making any noise. In post production you can use software to get rid of that noise. You can use Adobe Audition, Waves, ProTools or anything else with "noise reduction".

The only problem with noise reduction is that the more erratic the noise the harder it is to get rid of it. But, if the noise is more of a "white" noise it might help...at the very least!

Hope this helps....if all else fails, you can have one of your crew go outside and "fake death" in the road. The traffic will stop for the time he/she is in the road. This will work a bunch of times, and then the cops will eventually come. At that point, I'd tell your crew member to "fake sickness" or some other thing that will keep him/her from getting arrested. :)

Murph

Ken Tanaka · May 17th, 2004, 09:02 PM

Murph offered some good work-around suggestions. (I'm keen on the fake movie playing on a television.)

Unfortunately, regarding prevention ("insulation"), the fact is that there is really only one effective broad-spectrum form of sonic insulation: mass. There is nothing transparent that will offer any real help. Selecting a quiet time of day or a different location (or room) are probably better bets. If that's not possible, then your secondary goal will be to deaden the street noise to minimize its bounce off of the walls, ceiling and floor. To that end, you can cover off-frame surfaces with some heavy blankets such a movers blankets.

Jay Massengill · May 18th, 2004, 08:36 AM

I would also say that mic technique will be very important, including the possibility of using a different mic.
Unless your scenes are routinely populated with just one actor mumbling to themselves, then the ME66 would not be my choice for interiors with leakage of outside noise and multiple actors.
I know you said "no-budget", but i'd strongly suggest you beg, borrow or rent a good hypercardioid or even cardioid mic to give you greater flexibility in keeping the mic close to multiple actors without having the off-axis coloration and too-tight pattern the ME66 is likely to suffer from.
Your boom operator will also be one of the most important people in this project. They really need to know the task and have a good system of monitoring what is being recorded.

Betsy Moore · May 18th, 2004, 04:35 PM

It's almost completely a two-character piece and other posts on this site and dv.com warned against using long shotguns in interiors because of the echo problem. We bought the ME66 based on the prior posts so there's no money to rent (especially for the extended period of time we'd need it) another mic--do you have any suggestions to help us work with the mic we have? And yes, there is muttering:)

Glenn Chan · May 18th, 2004, 07:31 PM

If there are holes where the sound is leaking in then you can plug them (you have to plug all of them) to improve things.

2- Maybe there are certain days and time of day where traffic noise is low?

3- Change locations?!

Jay Massengill · May 19th, 2004, 09:59 AM

There will be 3 factors to balance in order to use the 66 successfully in this situation:
Indoor reverberation and the off-axis coloration the 66 can impart to the overall sound.
The leakage of outdoor noise into your shooting environment.
How to appropriately cover any spacing between the actors with the fairly tight pattern of the 66.

First I would work on padding the internal space to reduce reverb. Since this is supposed to be a cabin, you will have some flexibility to actually have blankets, comfortors, pillows, coats and other acoustically soft materials on camera without it looking odd. You can use moving blankets for other spaces off camera like the floor. You can also use a bedsheet (of the appropriate color for your overall lighting scheme) suspended across the ceiling with 4 thumbtacks. It should drape down from the ceiling in the middle, but not so much that it interferes with lighting, booming, camera shots etc.
Then work with the actors on their delivery. As long as they don't shout and you've done a good job padding, then the reverb shouldn't be too great a problem.

For the leakage problem, the other posts have been good. Cover, dampen or plug any opening or access point that you think you can. For the windows, you may want to try and build a cover for the window that is falsely lit from inside. You could use a Rosco diffusion material that's actually called "Silent Frost". It's a heavy rubbery light diffusion material that doesn't make noise in the wind. If you build this false window covering, with an internal light, you could actually shoot at night with the illusion of a frosted window.

To best defeat the intrusion of outside noise, you must keep the mic close to the actors. The direct sound from your actors decreases with the square of the distance. The ambient noise from outside will essentially be constant throughout the room. Think of it as looking through fog, you have to get closer to maximize the balance between actors and outside noise.
The tight pattern of the mic will work against you in this when the actors are spaced apart. You may have to carefully work out your shooting plan to accomodate not having to constantly and rapidly que the boom between actors. Doing this is difficult and leads to uneven sound character for edits. When the actors are close together this is obviously not so big a problem.

May 17th, 2004, 04:23 PM	#1
Betsy Moore Major Player Join Date: Mar 2003 Location: Los Angeles Posts: 444	Sound insulation We're shooting a no-budget hd movie set in a cabin in the mountains but the set is actually a redecorated apartment in Los Angeles. We're using a Senheisser Me66 shotgun mic for most of the audio. Unfortunately, even with all the windows closed we're still getting a little bit of street noise. We don't have the money, time, or expertise to rely on fixing it in post. I was wondering if anyone had advice on what kind of clear temporary insulation we could put on the windows, like putting up a big thick plasti, glass, plexiglass pane and resting it on the window sil. To make matters worse we're using the windows as a light source so we can't cover them completely (though we have covered them with fake frost/snow)--and we're going to be shooting in a non-airconditioned apartment on the east side in the early summer--with all the actors wearing winter clothes--so taking the insulation down and opening the windows between takes is a must unless we want to shoot a movie about fainting. Does anyone have any advice about what we could put up and how we could put it up and where we could get it? Thanks

May 17th, 2004, 06:34 PM	#2
Christopher C. Murphy Trustee Join Date: Sep 2003 Location: Boston, MA Posts: 1,707	Suggestion, if it's a short scene and you can get away with it...put a television on and show it when the scene starts. Record a fake "movie" that takes place in the streets, so people watching your movie will accept the noise in the room. It may not work in your scene if you are in a remote cabin and it's for a long time. But, maybe something similar might work? How about a radio in the background that adds some white noise, so you can cover up the street? Another idea is to "record" the sound of room with no one talking or making any noise. In post production you can use software to get rid of that noise. You can use Adobe Audition, Waves, ProTools or anything else with "noise reduction". The only problem with noise reduction is that the more erratic the noise the harder it is to get rid of it. But, if the noise is more of a "white" noise it might help...at the very least! Hope this helps....if all else fails, you can have one of your crew go outside and "fake death" in the road. The traffic will stop for the time he/she is in the road. This will work a bunch of times, and then the cops will eventually come. At that point, I'd tell your crew member to "fake sickness" or some other thing that will keep him/her from getting arrested. :) Murph __________________ Christopher C. Murphy Director, Producer, Writer

May 17th, 2004, 09:02 PM	#3
Ken Tanaka Retired DV Info Net Almunus Join Date: Dec 2001 Location: Chicago, IL Posts: 6,943	Murph offered some good work-around suggestions. (I'm keen on the fake movie playing on a television.) Unfortunately, regarding prevention ("insulation"), the fact is that there is really only one effective broad-spectrum form of sonic insulation: mass. There is nothing transparent that will offer any real help. Selecting a quiet time of day or a different location (or room) are probably better bets. If that's not possible, then your secondary goal will be to deaden the street noise to minimize its bounce off of the walls, ceiling and floor. To that end, you can cover off-frame surfaces with some heavy blankets such a movers blankets. __________________ Lady X Films: A lady with a boring wardrobe...and a global mission. Hey, you don't have enough stuff! Buy with confidence from our sponsors. Hand-picked as the best in the business...Really! See some of my work one frame at a time: www.KenTanaka.com

May 18th, 2004, 08:36 AM	#4
Jay Massengill Trustee Join Date: Jul 2003 Location: Burlington Posts: 1,976	I would also say that mic technique will be very important, including the possibility of using a different mic. Unless your scenes are routinely populated with just one actor mumbling to themselves, then the ME66 would not be my choice for interiors with leakage of outside noise and multiple actors. I know you said "no-budget", but i'd strongly suggest you beg, borrow or rent a good hypercardioid or even cardioid mic to give you greater flexibility in keeping the mic close to multiple actors without having the off-axis coloration and too-tight pattern the ME66 is likely to suffer from. Your boom operator will also be one of the most important people in this project. They really need to know the task and have a good system of monitoring what is being recorded.

May 18th, 2004, 04:35 PM	#5
Betsy Moore Major Player Join Date: Mar 2003 Location: Los Angeles Posts: 444	It's almost completely a two-character piece and other posts on this site and dv.com warned against using long shotguns in interiors because of the echo problem. We bought the ME66 based on the prior posts so there's no money to rent (especially for the extended period of time we'd need it) another mic--do you have any suggestions to help us work with the mic we have? And yes, there is muttering:)

May 18th, 2004, 07:31 PM	#6
Glenn Chan Inner Circle Join Date: Jun 2003 Location: Toronto, Canada Posts: 4,750	If there are holes where the sound is leaking in then you can plug them (you have to plug all of them) to improve things. 2- Maybe there are certain days and time of day where traffic noise is low? 3- Change locations?!

May 19th, 2004, 09:59 AM	#7
Jay Massengill Trustee Join Date: Jul 2003 Location: Burlington Posts: 1,976	There will be 3 factors to balance in order to use the 66 successfully in this situation: Indoor reverberation and the off-axis coloration the 66 can impart to the overall sound. The leakage of outdoor noise into your shooting environment. How to appropriately cover any spacing between the actors with the fairly tight pattern of the 66. First I would work on padding the internal space to reduce reverb. Since this is supposed to be a cabin, you will have some flexibility to actually have blankets, comfortors, pillows, coats and other acoustically soft materials on camera without it looking odd. You can use moving blankets for other spaces off camera like the floor. You can also use a bedsheet (of the appropriate color for your overall lighting scheme) suspended across the ceiling with 4 thumbtacks. It should drape down from the ceiling in the middle, but not so much that it interferes with lighting, booming, camera shots etc. Then work with the actors on their delivery. As long as they don't shout and you've done a good job padding, then the reverb shouldn't be too great a problem. For the leakage problem, the other posts have been good. Cover, dampen or plug any opening or access point that you think you can. For the windows, you may want to try and build a cover for the window that is falsely lit from inside. You could use a Rosco diffusion material that's actually called "Silent Frost". It's a heavy rubbery light diffusion material that doesn't make noise in the wind. If you build this false window covering, with an internal light, you could actually shoot at night with the illusion of a frosted window. To best defeat the intrusion of outside noise, you must keep the mic close to the actors. The direct sound from your actors decreases with the square of the distance. The ambient noise from outside will essentially be constant throughout the room. Think of it as looking through fog, you have to get closer to maximize the balance between actors and outside noise. The tight pattern of the mic will work against you in this when the actors are spaced apart. You may have to carefully work out your shooting plan to accomodate not having to constantly and rapidly que the boom between actors. Doing this is difficult and leads to uneven sound character for edits. When the actors are close together this is obviously not so big a problem.