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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => LAB: The Classic Live Audio Board => Topic started by: Robert Lunceford on October 07, 2019, 02:27:33 am

Title: Double Vox Mic
Post by: Robert Lunceford on October 07, 2019, 02:27:33 am
I believe that Grateful Dead was credited with developing the use of two out of phase vocal mics in order to reduce feedback for their "Wall of Sound" PA.
According to this article, the WOS was developed after Owsley Stanley was released from prison in late 1972. https://en.wikipedia.org/wiki/Wall_of_Sound_(Grateful_Dead)

This video of David Bowie shows him using a double vocal microphone July 1972 prior to O. Stanley being released from prison.
https://www.youtube.com/watch?v=3qrOvBuWJ-c&list=RDNZnryZ5rDbs&index=19

Does anyone know if Bowie's mics were out of phase for feedback rejection or was one going to the PA and the other being used for audio recording?
Title: Re: Double Vox Mic
Post by: Chris Grimshaw on October 07, 2019, 03:40:55 am
The double-mic-to-avoid-feedback technique would require two mics that are as close to identical as possible, and the two mics in the video look quite different.

I'd expect the two mics to be feeding to different mixers. Maybe one mons and one FOH, or one live and one recording.

Chris
Title: Re: Double Vox Mic
Post by: Art Welter on October 07, 2019, 11:31:07 am

Does anyone know if Bowie's mics were out of phase for feedback rejection or was one going to the PA and the other being used for audio recording?
The Dead's "Wall of Sound" dual matched reversed polarity condenser microphones were used for background noise cancellation, not feedback rejection.

As Chris mentioned, Bowie's two different mics would be used for feeding different consoles, typically for film or broadcast and PA when a transformer split was not available, or did not work due to noise problems, or the broadcast engineer desired a microphone that was not appropriate for use with the PA.
Photographs of different artists using taped together mics for that reason abound..

Art
Title: Re: Double Vox Mic
Post by: Ivan Beaver on October 07, 2019, 12:32:34 pm
The Dead's "Wall of Sound" dual matched reversed polarity condenser microphones were used for background noise cancellation, not feedback rejection.

As Chris mentioned, Bowie's two different mics would be used for feeding different consoles, typically for film or broadcast and PA when a transformer split was not available, or did not work due to noise problems, or the broadcast engineer desired a microphone that was not appropriate for use with the PA.
Photographs of different artists using taped together mics for that reason abound..

Art
I saw an interview with some of "The dead" members and they were talking about how much they hated those mics and how horrible they sounded.


Title: Re: Double Vox Mic
Post by: Riley Casey on October 07, 2019, 12:42:23 pm
Simply taping a second mic to the vocal mics was a very common technique for film and video production on early rock n roll movies.  Thats what you're seeing in the Bowie vid.  Differential mic designs were already used in helicopter communications headsets by the military at the time. No idea if there was any cross pollination to Owsley.