Convolution Reverbs for ADR 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 June 25th, 2006, 10:18 AM   #1
Inner Circle
 
Join Date: Mar 2005
Location: Hamilton, Ontario, Canada
Posts: 5,742
Convolution Reverbs for ADR

Been reading up on convolution reverbs like Sony's Acoustic Mirror and it occurred to me that these would be a great tool to use to add location ambience to studio-recorded ADR dialog. Has anyone used them in this way? If you have, how do you go about capturing the "impulse" or reference file while on set?
__________________
Good news, Cousins! This week's chocolate ration is 15 grams!
Steve House is offline   Reply With Quote
Old June 25th, 2006, 10:22 AM   #2
 
Join Date: Jan 2004
Location: Stockton, UT
Posts: 5,648
Quote:
Originally Posted by Steve House
Been reading up on convolution reverbs like Sony's Acoustic Mirror and it occurred to me that these would be a great tool to use to add location ambience to studio-recorded ADR dialog. Has anyone used them in this way? If you have, how do you go about capturing the "impulse" or reference file while on set?
been doing it for years.
You can record ambiences with any percussive object such as a ruler on a table, a hand-clap, etc, but all the impulses we've recorded for Sony, Cakewalk, and WAVES have been done using a starter pistol.
Put the mic in the position of the audience perspective you'd like to create. turn on Record. Fire the starter pistol from the position of the sound source, such as a stage. Drop the resulting wav into Mirror and it will convolute it for you, removing the audio and leaving you with the ambience.
__________________
Douglas Spotted Eagle/Spot
Author, producer, composer
Certified Sony Vegas Trainer
http://www.vasst.com
Douglas Spotted Eagle is offline   Reply With Quote
Old June 25th, 2006, 10:24 AM   #3
Trustee
 
Join Date: Feb 2004
Location: Brookline, MA
Posts: 1,447
http://dvinfo.net/conf/showthread.php?t=69191
Emre Safak is offline   Reply With Quote
Old June 25th, 2006, 11:15 AM   #4
Inner Circle
 
Join Date: Mar 2005
Location: Hamilton, Ontario, Canada
Posts: 5,742
Quote:
Originally Posted by Douglas Spotted Eagle
been doing it for years.
You can record ambiences with any percussive object such as a ruler on a table, a hand-clap, etc, but all the impulses we've recorded for Sony, Cakewalk, and WAVES have been done using a starter pistol.
Put the mic in the position of the audience perspective you'd like to create. turn on Record. Fire the starter pistol from the position of the sound source, such as a stage. Drop the resulting wav into Mirror and it will convolute it for you, removing the audio and leaving you with the ambience.
If one is slating the shots, how about lifting out the sound of the sticks hitting together and using it to set the reverb?
__________________
Good news, Cousins! This week's chocolate ration is 15 grams!
Steve House is offline   Reply With Quote
Old June 26th, 2006, 12:36 PM   #5
Major Player
 
Join Date: Jun 2004
Location: McLean, VA United States
Posts: 749
The problem with hand claps, slate claps, pistol shots etc is that they are not
"impulsive" enough (a true impulse is not a physically realizeable thing). In the olden days they used electric sparks to appoximate an impulse. Today it is more likely that a white noise source (impulsive auto correlation function), pseudo random noise source or swept sinewave source will be used for measurement and the room's impulse response derived mathematically from the measurements (of amplitude and phase). Once the impulse response is available sounds can be made to sound as if they were recorded in that room be they speech, noise or anything else. Filtering white noise with the impulse response of the room should give something like the actual ambience. Speech convolved with that impulse response should sound as if it were recorded in that room (provided that the speech going in was recorded in a dead room) etc.
A. J. deLange is offline   Reply With Quote
Old June 26th, 2006, 01:01 PM   #6
 
Join Date: Jan 2004
Location: Stockton, UT
Posts: 5,648
White noise was used for the Sydney Opera House samples for WAVES, but to my knowledge, that's the only place white noise was used.
I'd guess we've recorded perhaps 10,000 or more ambiences for libraries in use/sold by Cakewalk, Sony, WAVES, Apple, and at one time, Qup Arts. All were acquired using a starter pistol, and to date, I've not received one complaint/letter/email from anyone about it.
Would/could white noise be better? Potentially. It's also a lot of hassle to set up. Hassle factor doesn't guarantee a better result.
Sometimes impulses that come from non-percussives work exceptionally well too. For example, creating a convolved verb from a full snip of a song's hook and refeeding it as a convolution sounds awesome. Lotta hassle, but sometimes that pays off too.
It really depends on if you're after making a creative point and final product or if you're intent on being an engineer that plays in the lab and never ventures into the sandbox.
FWIW, I'm a mathematical idiot, but I've created some exceptionally spectacular reverbs in locations ranging from volcanoes to mineshafts, opera houses to bridges, toilet paper tubes to 12" PVC pipes, and other unique locations/devices. We even made some very unique convultions using a Cooper tube being fed pitched-down kick drums.
__________________
Douglas Spotted Eagle/Spot
Author, producer, composer
Certified Sony Vegas Trainer
http://www.vasst.com
Douglas Spotted Eagle is offline   Reply With Quote
Old June 26th, 2006, 01:36 PM   #7
Inner Circle
 
Join Date: May 2006
Location: Camas, WA, USA
Posts: 5,513
For small spaces, and conditions where the source is fairly close to the mic, you can use a balloon pop, rather than a starters pistol. One advantage is that nobody calls the cops on people for popping baloons.
__________________
Jon Fairhurst
Jon Fairhurst 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 07:03 AM.


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