Don't mean to muddy the brew, here, but I think there are some
misconceptions with regard to the ways in which stereo and 360 sound are
being applied.
STEREO is a class of systems whereby a recording is typically made using
two microphones. It includes (A) XY stereo recordings where two mics of the
same type, usually omnis or cardioids are used in a coincident
configuration although there are a number of other configurations possible.
(B) Binaural, which, itself is divided into sub-classes including straight
binaural (as, for instance, the Neumann or Aachen head configurations with
omnis implanted in the ears), the SASS Lang prefers and uses, and a few
lesser known types that are a bit esoteric for this discussion. (C) M-S, or
Mid-Side.
It should be pointed out that none of the stereo systems offers a true 360
degree listening experience by itself. To me, a realistic 360 degree
experience means that you can place the listener within a non-headphone
tethered sound field and anywhere he/she turns his/her head, they will hear
the sound accurately portrayed from that perspective. 360 degree sound is
listener-oriented and determined just as sound arrives at our ears in the
real world. That can be currently accomplished by discrete 4-channel
recordings or (as we have recently tested) two M-S systems placed
butt-to-butt, and perhaps some other method(s) not yet well-known or
explored like, perhaps, a tetrahedral array (giving the added advantage of
height as well as depth of field on the horizontal plane).
Each system has its own advantages and disadvantages because none does all.
Some are easier to use in the field than others. Some offer the listener a
rich on-site monitoring experience that engages him/her. Some offer a
post-production experience guaranteed to cause listeners to swoon. Some
provide a wide range of production and post-production options. Some are
limited in their range of patterns. Basically, it all boils down to what
one determines one wants to hear in your "mind's ear" and at what stage in
the process.
It's all a matter of taste. Test a whole bunch out and go with what pleases
YOUR ear. I recommend using systems that are durable, easy-to-use, provide
a good to excellent signal-to-noise ratio, and a reasonable to great
illusion of space. Except for the specially configured SASS system
described by Lang (and which we WILL explore when we get the bucks to do
it), we use all types and all configurations depending on the application
and what we wish the end result to be. Call me an end-resulter, if you
wish. (I won't be insulted 'cause I'm just wired that way.) I go for what
the illusion will sound like on a CD or in a public space installation so I
don't necessarily monitor for the pleasure of the moment in the field. I'm
happy enough to be there in the first place. Rather I monitor just to be
sure that the M-S recording on tape or disc is as fine as it can be knowing
that in the studio it will be close to what I imagined it should be, then
detach the headphones. The M-S system we use is more difficult than other
systems because it is not intuitive. What you hear using a simple pre-amp
in the loop is clearly not a representation of what can be got in the
studio or lab when doing the final mix. So I usually recommend simpler
stereo systems to begin with.
This discussion reminds me of a story told in my last book (INTO A WILD
SANCTUARY, Heyday Books). Elizabeth Wilson was a Nez Perce tribal member
who knew Chief Joseph (1836-1904) meeting him at her graduation from
Carlisle Indian School in Pennsylvania in 1904 where he gave what was to be
his last speech at the commencement. During a break in our session while
collecting oral histories on the reservation in Idaho in the early 70s, she
guided me around a graveyard near her home pointing out different family
members and telling some of their fascinating histories. "You know," she
said at one point, "each of my family members belonged to many different
churches. When the missionaries came they brought Catholicism, LDS, three
or four Protestant groups, all competing for our souls. We fooled 'em real
good, though. Joined 'em all." "Why on earth did you do that," I asked
naively? "You white boys know nothing," she quipped, her 91 year old voice
rising to the occasion, repeating a sentiment I heard often during those
sessions. "We get a little power from the Catholics. We get some from the
Mormons. And some from the Baptists, and even some from the Moravians. And,
of course, we got Indian religion. With all that power, how can we lose?"
Lesson the long way 'round: use different mics and find one or several you
like.
Bernie Krause
>I agree with Lang's comments the two have different applications.
>I can not take my foam block mic and easily record a duet between two
>birds the way that you can with your cardiods. With modification I
>will be able to do some of that but it still not as well. I also
>agree that your config is better for the normal speaker setup that is
>in use today. The weakness in your config is in setting up an open
>mic.
>
>In spring I enjoy doing an afternoon of searching for special species
>rich yet people quiet areas. Then I return predawn to setup an open
>mic. I have been waiting for the ability to do this stereo and look
>forward to the full spring this year. For this type of site recording
>I want the 360 degree sound.
>
>--- In Vicki Powys <> wrote:
>> Lang, Rich and All,
>>
>> Your very clear comments on 360 degree sound are much appreciated,
>Lang.
>> And after reading the PDF file mentioned by Walt on boundary mics
>and SASS,
>> I am further enlightened.
>>
>> > Walt wrote:
>> > The SASS and PZM in general is discussed fairly well in the Crown
>> > Boundary Microphone Application Guide, which I recommend all who
>are
>> > thinking of making a SASS read. Available in pdf here:
>> > http://www.crownaudio.com/mic_htm/mic_pubs.htm
>>
>> My next question is, how much difference would there be for
>realistic stereo
>> effects, using binaural and omni mics, compared with my present set
>up of a
>> co-incident pair of cardoid mics? Is binaural worth the hassle, is
>it
>> noticeably superior? And could you make a sphere using upholstery
>foam or
>> should the material be more dense?
>>
>> Vicki Powys
>> Australia
>>
>>
>>
>> > on 5/2/02 1:09 AM, Lang Elliott at wrote:
>>
>> > Rich:
>> >
>> > I think your setup will produce a very nice binaural-like effect,
>and it is
>> > similar in many respects to what you'd get using a sphere setup
>like the one
>> > designed by Schoeps. Really, yours is a simple setup using a
>barrier to
>> > isolate and directionalize the two microphones.
>> >
>> > While I can't know for certain, the primary weakness will
>probably be poor
>> > imaging (= localization) of sounds off to the sides. The reason
>is pretty
>> > simple. Because of the large size of the barrier and its shape, I
>doubt that
>> > movement of sounds sources straight out to the sides (for
>example, a sound
>> > source moving in a thirty degree arc off to one side) would
>result in
>> > significant changes in the signals arriving at the two mikes. If
>there are
>> > no differences at the mikes, then such subtle movements would not
>be audible
>> > over headphones or speakers.
>> >
>> > On the other hand, frontal or rear sound sources moving from left
>to right
>> > or vice versa will be imaged much better due to the barrier
>design of your
>> > setup. At least that's my guess.
>> >
>> > One good way to test all binaural mike setups is to do a "walk
>around"
>> > recording where you begin out front and center, then walk all the
>way
>> > around, talking to the mike all the while. Return to the center,
>then walk
>> > the other way. As you're talking, describe where you are in
>relation to the
>> > mike so that you know this upon playback. In other words,
>say "front center"
>> > when you're at that location. Other positions where you should
>stop and
>> > identify them should be "right 45 degrees", "right 90
>degrees", "right rear
>> > 135 degrees", "rear center", and so forth. But remember to talk
>all the
>> > time, even when you're moving between positions.
>> >
>> > Then, depending on your playback techique (via speakers or
>headphones), you
>> > will see how sound sources from all these directions translate
>into the
>> > final listening soundfield, and how well you can image your voice
>moving
>> > from position to position.
>> >
>> > This simple test will tell you a lot about how the final
>listening illusion
>> > is created, and it's a very good way to test the effects of
>different
>> > speaker arrangements.
>> >
>> > Lang
>>
>> >
>> > For the best 360 degree binaural, I think that some of you should
>experiment
>> > with sphere setups, using spheres with a diameter of around 19-20
>cm (=
>> > 7.5"). The Schoeps KFM 6 has a diameter of 20 cm.
>> >
>> > Of course, the ease with which one can do this depends on the
>mikes used,
>> > and how they could be inserted or mounted inside the sphere so
>that their
>> > elements are flush with the surface.
>> >
>> > That said, I do want to say that the SASS setup will probably
>serve most of
>> > you better than a sphere under most circumstances. The SASS
>produces
>> > excellent imaging of sounds in the 180 degree frontal soundscape,
>and also
>> > has fair rejection of sounds to rear (which is usually desired).
>Sphere
>> > mikes are just as sensitive to the rear, which will often be a
>considerable
>> > annoyance as such a setup will hear you breathing and swallowing,
>unless
>> > you're at a distance from the mike.
>> >
>> > With my SASS setup, I usually use a ten foot cable and stand back
>while
>> > recording. This works pretty well unless my stomach grumbles. I
>actually
>> > prefer to use a longer cable, placing myself twenty or thirty
>feet behind
>> > the mike so that I can relax and make my normal creature-noises
>without
>> > worry.
>> >
>> > Lang
>> >
>> >> Rich and All,
>> >>
>> >> Your 360 degree mic set up looks wonderful, Rich. I can't see
>that the
>> >> sound would be all that different to the Schoeps stereo sphere
>that Lang
>> >> mentioned. What sort of mics are you using? I'd love to hear
>some sample
>> >> recordings. Does this set up work best with headphone listening
>or with
>> >> speaker listening? How thick is the foam?
>> >>
>> >> Vicki Powys
>> >> Australia
>> >>
>> >>
>> >>
>> >>
>> >>
>> >>> on 2/2/02 11:12 AM, richpeet at wrote:
>> >>
>> >>> ok, honest please, no holds barred. Upfront, slam dunk, is
>requested.
>> >>> Here is an outdoor stereo setup. I am not able to see a hole in
>the
>> >>> middle.
>> >>>
>> >>> I seem to get a full 360 for dawn forest recording and have
>another
>> >>> chunk of foam for a rear block that I can attach for a T with
>> >>> coathangers punching through if I want a block in a given
>direction.
>> >>>
>> >>> Granted I have no PZM gain which I wonder if it is freq specific
>> >>> anyway.
>> >>>
>> >>> What is the weakness of this system. I can post sample
>recordings if
>> >>> requested as well.
>> >>>
>> >>> The foam was $3.00. The mics over $600.00. The stand $15.00.
>> >>>
>> >>> http://people.mn.mediaone.net/richpeet/sounds/foam1.jpg
>> >>>
>> >>> http://people.mn.mediaone.net/richpeet/sounds/foam2.jpg
>> >>>
>> >>> I agree I need some polishing but tell me where.
>> >>>
>> >>> Rich Peet
>> >>>
>> >>>
>
>
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Wild Sanctuary, Inc.
P. O. Box 536
Glen Ellen, California 95442-0536
Tel: (707) 996-6677
Fax: (707) 996-0280
http://www.wildsanctuary.com
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