naturerecordists
[Top] [All Lists]

Re: mono and pseudo-stereo?

Subject: Re: mono and pseudo-stereo?
From: Lang Elliott <>
Date: Tue, 15 Jun 2004 10:05:16 -0400
The WaveSurround Pro plug-in includes a setting for converting monaural to
stereo, and they include an audio example of what it does on their web site:

http://www.wavearts.com/WaveSurroundPro.html

Lang

By copying the left channel to the right (assuming it is exactly the
same material and aligned) you'll get two-track mono and not
pseudo-stereo, Julie. There are, however, a number of processes, both
analog and digital, from which you can derive pseudo-stereo - or at
least a stereo illusion (a false sense of space from a mono track).
The oldest is the Orban system (analog, 1968), which takes a mono
track and divides the signal into 5 frequency bands. At each
crossover point (the point at which a frequency band is separated
from its nearest neighbor) Bob Orban introduced a 90 degree phase
shift. Channels 1, 3, and 5 (the odds) were placed on the left.
Channels 2 and 4 (evens) were placed on the right. The neat things
about the Orban is that all of the controls are continuously variable
(and/or voltage controllable) so that one can adjust the quality of
the illusion to one's taste, and that by re-combining right and left
channels, one can get an exact duplication of the original mono
source. Later digital versions of stereo synthesizers, such as those
available as part of multiple programs in the Alesis Quadraverb
device (among others), offers variations on that theme. Some are
really quite impressive given the mono source.

When I first began to record M-S in the late 80s, I brought into the
field a martix (Schoeps) with which I was completely unfamiliar
having received it just a day before I left for an African trip.
During the entire time in the field, my mic cables were plugged into
the wrong inputs on the matrix (which I didn't realize even though I
thought I was monitoring correctly). Consequently, I lost a months
worth of work at Jane Goodall's research site in Gombe. It was only
when I got home that I realized that all I had was mono data.
Horrified and embarrassed, I've spent the past dozen years trying to
figure out how to derive stereo from those otherwise vaulable mono
recordings. Using a carefully calibrated combination of analog and
digital processes, I've managed to create a reasonable stereo
illusion and recover some of the "space" present in that environment.
It ain't the same. But it's better (different) than mono.

Bernie Krause

Wild Sanctuary, Inc.
P. O. Box 536
Glen Ellen, California  95442-0536
Tel: (707) 996-6677
Fax: (707) 996-0280
http://www.wildsanctuary.com

>Now I use only one Mic for my maranz, so my music file was mono. But
>then  what's the difference if I copy the left channel to right
>channel and make  it as a stereo file? It really occupy a lot of
>memory, but then what's the  difference of hearing btw the mono
>and "pseudo-stereo"?
>
>Thank you!
>
>A beginner, Julie
>
>
>
>
>
>"Microphones are not ears,
>Loudspeakers are not birds,
>A listening room is not nature."
>Klas Strandberg
>Yahoo! Groups Links
>
>
>
>





[Non-text portions of this message have been removed]



________________________________________________________________________
________________________________________________________________________

<Prev in Thread] Current Thread [Next in Thread>
Admin

The University of NSW School of Computer and Engineering takes no responsibility for the contents of this archive. It is purely a compilation of material sent by many people to the naturerecordists mailing list. It has not been checked for accuracy nor its content verified in any way. If you wish to get material removed from the archive or have other queries about the archive e-mail Andrew Taylor at this address: andrewt@cse.unsw.EDU.AU