[78-L] Binaural, duophonic, etc.

[Jeff Sultanof]

Not to get picky, but the wasn't the DeParis Atlantic? I distinctly remember
seeing a copy of it at some point.

Jeff Sultanof

On Thu, Apr 21, 2011 at 2:40 PM, Steve Williams <jazzhunter at collector.org>wrote:

>
> Mike Biel is correct.  I was referring to the Blumlein "Matrixed" method of
> using a unidirectional wide pattern cardoid facing forwards, which is
> summed
> with the left-pointing cardoid and subtracted from the right-pointing mic -
> Or something like that.. :-) But anyway David is right, that is not a
> correct method of capturing accurate "two-ear" imaging but can provide
> exceptionally realistic sound for playback on two speakers.  (I was at work
> and typing hastily.) When referring to Binaural, Stereo etc. I was going by
> current-day understanding of their meaning, I realize the terms were used
> differently in the past.
>
> I have the 1952 Mercury Wilbur DeParis Cook "Binaural" LP, and wonder how
> on
> earth anyone expected to get proper results using a twin spiral.  (Many
> many
> years ago I stumbled upon a hoarder-of-anything who happened to have a NIB
> Cook arm among his detritus.  I begged and pleaded to get it from him, who
> didn't even know what it was, to no avail.)  But regardless, having two
> channels is just the start of the equation; most critical is that accurate
> timing of the two channels is necessary to maintain accurate phasing to
> preserve the imaging used by the ear to judge direction and distance of the
> source.  All early forms of record-playback equipment, except multitrack
> film, could not preserve that accuracy. Even early CD players which used
> only one DA convertor were anathema to Golden ears who could detect the
> timing error introduced between the two channels. Staggered-head tape
> machines were getting there, but still fussy, until finally stacked audio
> heads and single-track record cutting were developed.  I guess the Decca
> vertical-Horizontal matrixed method of cutting was similar to the Blumlein
> matrixed mic pickups, and FM radio with the AM sideband subcarrier
> providing
> the difference signal to the FM summed channel.
>
> Steve Williams..
>
> Date: Wed, 20 Apr 2011 14:02:08 -0700 (PDT)
> From: DAVID BURNHAM <burnhamd at rogers.com>
> Subject: [78-L] Binaural, duophonic, etc.
> To: 78-L at 78online.com
> Message-ID: <414652.32411.qm at web88103.mail.re2.yahoo.com>
> Content-Type: text/plain; charset=us-ascii
>
> Dan Van Landingham wrote:
>
> "Binaural" refers to a method of recording that mimics the human
> ear. - "Two Sounds." The microphones are literally mounted on a Styrofoam
> head in some cases, or a single crossed-8 cardoid stereo mic is used.  The
> listener wears headphones.
>
> ~~~~~~~~~~~~~~~~~~~
>
> As dl has pointed out, Duophonic was a Capitol term for simulated stereo.
>  Binaural recordings have to be made using microphones spaced approximately
> the
> same distance apart as the distance between a pair of ears, just like
> stereo
>
> photography uses two cameras which are eye-spaced apart.  In both cases the
> signal for the left ear/eye cannot reach the right ear/eye or it won't
> work.
>
>  That's why headphones or some sort of glasses must be employed
> respectively
>
> BUT the second half of the above statement is not only wrong, but is
> confusing.
>  There are several different kinds of mikes, based on polar patterns;  two
> of
> these are Cardioid and figure of 8.  Crossed figure of 8, (or
> bidirectional)
>
> mics will yield superb stereo recordings reproduced on speakers.  This is
> known
> as an XY system and was regularly used by BBC and EMI in the early days of
> Stereo.  The system was invented by Alan Blumlein and bears his name.  A
> bidirectional mike is also known as a cosine mike because the level of
> pickup is
> proportional to the cosine of the angle of incidence on the mike.  This may
> sound confusing but what it means is that this particular pickup is ideal
> because when your position to the mike is 90 degrees, which in an XY system
> is
> the direction from which the right signal will be arriving to the left
> channel
> mike, the output is theoretically zero, (the cosine of 90 degrees is "0").
> At
> 45 degrees, which is the angle at which each mike will be picking up a
> centre
> sound source, the output of each mike is reduced by half.  If a speaker
> walks
> from the extreme left to the extreme right of an XY pair of figure 8s, his
> voice
> level will not vary and the direction of the image will be identical to his
> position on the sound stage.
>
> Crossed cardioids, on the other hand, produce a less than ideal stereo
> image.  A
> cardioid mike is only down a couple of dBs at 90 degrees so a signal from
> the
> right side of the sound stage will produce a considerable signal to the
> left
>
> channel mike.  If the same speaker walks across a XY pair of cardioid
> mikes,
> the
> image will never be at the extreme left or right and the voice will be
> louder
> when he is at the centre, (called centre channel build up).
>
> In any case, neither of these situations will produce binaural recordings
> because the inter-channel time difference which is required for binaural
> reproduction is totally absent when using a coincident stereo mike.
>
> db
>
> ------------------------------
>
> Message: 9
> Date: Wed, 20 Apr 2011 19:26:35 -0400
> From: Michael Biel <mbiel at mbiel.com>
> Subject: Re: [78-L] Binaural, duophonic, etc.
> To: 78-L Mail List <78-l at klickitat.78online.com>
> Message-ID: <4DAF6BAB.7040701 at mbiel.com>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> On 4/20/2011 5:02 PM, DAVID BURNHAM wrote:
> > Dan Van Landingham wrote:
> >
> > "Binaural" refers to a method of recording that mimics the human
> > ear. - "Two Sounds." The microphones are literally mounted on a Styrofoam
> > head in some cases,
>
> Let me mention again that this use of the word was not solidified until
> the 1960s.  Prior to this binaural was used for just about any
> two-channel recording, including some that have w-i-d-e separation.
>
> >   or a single crossed-8 cardoid stereo mic is used.  The
> > listener wears headphones.
> >
>
> The explanation below is quite good, but I think that the above
> description might have been mis-understood because the wording is a
> little confusing.  Blumlein and others didn't always use a pair of
> bi-directional with one facing forward and the other facing sidewards.
> Sometimes a cardioid is used facing forward and the bi-directional
> pattern is facing sidewards.  I think this is what is meant in this
> description.  Using a cardioid as the forward facing mic instead of a
> bi-directional reduces pickup from the rear, such as audience noise and
> hall reverberation.   Stereo mics like the AKG C-24allowed for the
> changing of the patterns -- in the case of the C-24 even from the
> control room while listening to the results live!
>
> Mike Biel  mbiel at mbiel.com
> > ~~~~~~~~~~~~~~~~~~~
>
>
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