[Arny Krueger[_4_]]

"Gary Eickmeier" wrote in message
...
OK, I have been sufficiently worked over for now. I thank you all - or
both - for some great discussion. You have read what I said, and that is
all
I can ask.

NOW, assuming I am all washed up, that my statements that there is no
stereo
theory even at this late date in audio history is wrong, I sit at your
feet
as a student.

How does stereo work?


Strictly speaking Stereo over speakers doesn't work because it can't work.
It's just like a car with 110% thermodynamic efficiency.

It is an acceptable illusion or at least an illusion that many find
acceptable.

[Gary Eickmeier]

"Arny Krueger" wrote in message
...

Strictly speaking Stereo over speakers doesn't work because it can't work.
It's just like a car with 110% thermodynamic efficiency.

It is an acceptable illusion or at least an illusion that many find
acceptable.

Hi Arn -

For the record (so to speak) - when I use the term "stereo" I am using it as
shorthand for any and all loudspeaker based auditory perspective systems.
This would include 3 channel, DD 5.1 surround sound, or any number of
speakers placed around a room to try and reconstruct a sound field that
mimics the original. I realize that to some, "stereo" means strictly two
channel, but that is not what I mean. But if I use "surround" or
"multichannel" in all discussions, people will think I am limiting the
discussion to more than two channels, which I am not. Stereo can work with
two or more speakers and the general principles apply to all of these.

I hope that most of you are listening in surround sound to all recordings,
even two channel. If so, you are at least partially agreeing with me on the
reconstruction principle. If not, I've got my work cut out for me....

Gary Eickmeier

[Audio Empire]

On Mon, 28 May 2012 11:13:04 -0700, Gary Eickmeier wrote
(in article ):

"Arny Krueger" wrote in message
...

Strictly speaking Stereo over speakers doesn't work because it can't work.
It's just like a car with 110% thermodynamic efficiency.

It is an acceptable illusion or at least an illusion that many find
acceptable.

Hi Arn -

For the record (so to speak) - when I use the term "stereo" I am using it as
shorthand for any and all loudspeaker based auditory perspective systems.
This would include 3 channel, DD 5.1 surround sound, or any number of
speakers placed around a room to try and reconstruct a sound field that
mimics the original. I realize that to some, "stereo" means strictly two
channel, but that is not what I mean. But if I use "surround" or
"multichannel" in all discussions, people will think I am limiting the
discussion to more than two channels, which I am not. Stereo can work with
two or more speakers and the general principles apply to all of these.

I hope that most of you are listening in surround sound to all recordings,
even two channel. If so, you are at least partially agreeing with me on the
reconstruction principle. If not, I've got my work cut out for me....

Gary Eickmeier




Frankly, I find that the recording industry has a hard enough time doing two
channel stereo correctly, much less four channels, or five or seven.... Now
for movies where the extra channels have explosions and other sound effects
pan-potted to them, it's fine, but I have yet to hear a music surround
recording where I thought that the surround was any more than a gimmick.

[Dick Pierce[_2_]]

Gary Eickmeier wrote:
For the record (so to speak) - when I use the term "stereo" I am using it as
shorthand for any and all loudspeaker based auditory perspective systems.
This would include 3 channel, DD 5.1 surround sound, or any number of
speakers placed around a room to try and reconstruct a sound field that
mimics the original. I realize that to some, "stereo" means strictly two
channel, but that is not what I mean. But if I use "surround" or
"multichannel" in all discussions, people will think I am limiting the
discussion to more than two channels, which I am not. Stereo can work with
two or more speakers and the general principles apply to all of these.

Mr. Eickmeier, you have a lonn history of taking a term,
redefining it for the purposes of some agenda, without
letting anyone else know about your surreptitious redefinition,
and then proceeding to argue from that point.

For the record, "surround sound" was NEVER designed as a means
of recreating the original sound field. Things like 5.1 surround
and the like were developed as effects systems used in conjunction
with video and the like. James Jophnston has elsewhere described
how completely innappropriate surrtound-sound systems are for
recreating sound fields. Perhaps you might want to research
the subject before you hold forth on it.

As to the "definition" of stereo sound, you may well like to
redefinf it however you like, but you should note that there's
an 80 jump on your claim to the definition, and should you
disagree, you might want to take it up with the kind folks
at Bell Labs.

I hope that most of you are listening in surround sound to all recordings,
even two channel. If so, you are at least partially agreeing with me on the
reconstruction principle. If not, I've got my work cut out for me....

Yes, among other things, you have a LOT of reading up to
do, not the least of which is on fundamental definitions.

--
+--------------------------------+
+ Dick Pierce |
+ Professional Audio Development |
+--------------------------------+

[Audio Empire]

On Tue, 29 May 2012 03:30:00 -0700, Dick Pierce wrote
(in article ):

snip
As to the "definition" of stereo sound, you may well like to
redefinf it however you like, but you should note that there's
an 80 jump on your claim to the definition, and should you
disagree, you might want to take it up with the kind folks
at Bell Labs.

Now here, you and I agree. Bell Labs defined stereo for the ages back in the
early 1930's as I have mentioned at least once in this thread. Mr.
Eickmeier's attempt to redefine it is fraught with problems, to say the
least.

[Gary Eickmeier]

"Dick Pierce" wrote in message
...

Mr. Eickmeier, you have a lonn history of taking a term,
redefining it for the purposes of some agenda, without
letting anyone else know about your surreptitious redefinition,
and then proceeding to argue from that point.

Mr. Pierce, what a treat! Thank you for taking the time to share your
extensive knowledge.

For the record, "surround sound" was NEVER designed as a means
of recreating the original sound field. Things like 5.1 surround
and the like were developed as effects systems used in conjunction
with video and the like. James Jophnston has elsewhere described
how completely innappropriate surrtound-sound systems are for
recreating sound fields. Perhaps you might want to research
the subject before you hold forth on it.

Hey, what a great idea! But, indeed, I have been reading voraciously about
all this for over 30 years now! But I didn't stumble across a statement like
that - do you have any references or quotes to help us out here?.

As to the "definition" of stereo sound, you may well like to
redefinf it however you like, but you should note that there's
an 80 jump on your claim to the definition, and should you
disagree, you might want to take it up with the kind folks
at Bell Labs.

Gosh, it sure seems like you know something there that I don't - but. I have
quoted the research from Bell Labs in my various papers and writings. My
favorite reference is William B. Snow's 1953 paper
that is republished in the AES Anthology of Stereophonic Techniques. In it,
he defines all of the auditory perspective systems.

Yes, among other things, you have a LOT of reading up to
do, not the least of which is on fundamental definitions.

Thanks for the tip. So let me read to you for a minute:

From R. Vermeulen's paper on Stereo Reverberation (JAES, vol. 6, no. 2, pp.
124 - 130, 1958 April):

NECESSITY FOR AUGMENTED REVERBERATION

It is true that by suitable positioning of the microphone we can pick up
reverberation sound from the hall and reproduce the plolongation of the
sound. But here again, we are apt to make the same mistake in that we
reproduce only one and - of course - the only measurable characteristic of
the sound field, viz, the reverberation time, but neglect its spatial
distribution. The loudspeakers of a stereophonic set can never reproduce the
sound field in the concert hall with any accuracy in the home; how indeed
could they do so with only the data from two microphones at their disposal?
Neither can they deliver to the listener's ears exact copies of the
instantaneous sound pressure at the place of the microphones, if only
because the listeners are free to move their heads and are sitting at
different places. The loudspeakers can only produce a quite different sound
field, which will nevertheless give an impression that resembles the
original in certain respects. But not in all rexpects, beause they are only
capable of simulating sound sources in the space between them. Thus
stereophony can only widen the "hole in the wall of the concert hall" to a
"large window" but it cannot give the listener the impression that he is
present in the auditorium. It cannot imitate the sound reflected from all
sides by the ceiling and the walls. This does not matter as long as the
reproduction takes place in the concert hall itself where the ceiling and
the walls are present to produce reverberated sound with the desired
properties. In a living room, however, the absence of enough reverberated
sound or at least its different character places the listener in the positon
of an outsider."

He goes on to describe how to simulate the reverberant field by means of a
distribution of loudspeakers.

Permit me one more quote, this time from Blauert (the well-known Spatial
Hearing book, p 282) in describing the two basic approaches to transmitting
a spatial impression across a distance of space and time:

"In principle two approaches to solving this problem are possible. One
consists of generating a sound field in the playback room that corresponds
largely to that in the recording room. Such an electroacoustically generated
sound field is called a 'synthetic sound field.' The second approach
proceeds from the assumption that an optimal acoustical reproduction is
attained if the subject's ear input signals are collected, transmitted, and
reproduced. Processes employing this technique are called binaural or 'head
related' since a head, usually a dummy head, is used in collecting the ear
input signals."

His "synthetic sound field" is a large collection of microphones leading to
a similar number of speakers around the subject in an anechoic environment,
in an attempt to duplicate the original field as much as possible, or
necessary. Surround sound in the home theater system is a simplification of
this approach, which most of us realize by common sense.

You might want to do some more reading on this subject, starting
with those two sources. It is possible that you could use some reinforcement
in acoustics and psychoacoustics.

Gary Eickmeier

[KH]

On 5/30/2012 2:41 AM, Gary Eickmeier wrote:
"Dick wrote in message
...

large snip

Thanks for the tip. So let me read to you for a minute:

From R. Vermeulen's paper on Stereo Reverberation (JAES, vol. 6, no. 2, pp.
124 - 130, 1958 April):

NECESSITY FOR AUGMENTED REVERBERATION

It is true that by suitable positioning of the microphone we can pick up
reverberation sound from the hall and reproduce the prolongation of the
sound. my emphasis.

Quite a relevant point that I've been endeavoring to have you
understand. Thank you for pointing out the reference - there is no
"spatial" information in the signal. Level and arrival time. That's it.


But here again, we are apt to make the same mistake in that we
reproduce only one and - of course - the only measurable characteristic of
the sound field, viz, the reverberation time,

Note - time...the *only* measurable characteristic. There is no other
recording parameter to capture "spatial" information. Here's your
answer to your "smartass" question. Rhetorical on your part evidently.

but neglect its spatial
distribution. The loudspeakers of a stereophonic set can never reproduce the
sound field in the concert hall with any accuracy in the home; how indeed
could they do so with only the data from two microphones at their disposal?

Wow, this guy's good. You indeed can never reproduce the sound field in
the venue when using only two microphones for the recording. Why?
Simply because, as he states above, the spatial information is not
encoded in the signal. Note, recordings using 3 mics, or any number of
close-miked instruments panned into place will suffer the exact same
effects. Wonder where I've heard that before...


snip

He goes on to describe how to simulate the reverberant field by means of a
distribution of loudspeakers.

And corresponding microphones. This in no wise supports your method of
taking a signal devoid of non-temporal spatial information (i.e. no
incident angle info) and by bouncing the entire - direct and reverberant
- signal off the wall(s), thereby introducing an artificially delayed
acoustic wave superimposed on the directly radiated signal (which also
contains both the direct and reverberant data). While you may sense
that as spaciousness, it is clearly less accurate.

And as Mr. Pierce accurately observed, morphing the term "stereo" to
incorporate any number of speakers in any configuration is, IMO, clearly
a dodge. If you want to discuss surround sound - the term you clearly
know is universally applied - say so.

Keith

[Doug McDonald[_6_]]

Actually I suspect that 4 mikes is enough to establish a
soundfield and am quite sure that 16 would be.


That is for the soundfield impinging on one spot of course.

The four mikes would be four omnis in a spaced tetrahedron,
say 10 inches on a side.

The sixteen would be in groups of four coincident ones at the points of the same tetrahedron.
These would consist of one omni and three figure 8 ones, the three figure
8 ones being pointed up-down, east-west and north-south.
Or, alternatively, four cardioids pointing out from the center
of the tetrahedron.

This would allow computerized localization of
a single sound source generating a sine wave, or
localization of the original and reflections of a
point impulse source. Of course doing this for a whole
orchestra would be an immense and probably somewhat
impractical computer programming job. The accuracy would
decrease at low frequencies of course.



Doug McDonald