[Gary Eickmeier]

Andrew Haley wrote:

So, nothing short of proving that radiation pattern, speaker
positioning, and room acoustics are not audible will make you doubt
your theories. But we already know that thse things are audible, so
there is no experiment that could be done by anyone that would make a
diference to you.

Andrew.

Er - excuse ME, but then you agree with me. I have said that those factors
are audible and we should study the reproduction problem from the standpoint
of what those do to the sound. Linkwitz asked the same question, is there a
way to distinguish which variations of those factors lead to greatest
realism in the reproduction.

But there is a way to visualize the whole situation, a method that is time
honored and not controversial, and it is called image modeling. My
contribution is to propose that we study the reproduction problem from the
standpoint of comparing the image model of the live event to that of the
reproduction system of speakers and room. Most studies about stereo have
dealt with only the direct sound radiated from a pair or a line of speakers.
I point out that this approach sees the problem as a "windowing" or
portaling process, but that it might operate more like a model of the real
thing in which we should pay attention to the sound patterns produced in the
room by the full model, not just the direct field.

I relate my success with this approach both in my own system and in an
experiment conducted by my audio club.

I fully realize that all the talk in the world will not prove any of it to
you just by reading what I have written, but you may have already
experienced the effect that I am talking about in your listening experience.
Writers and audiophiles talk about the "floating" of images, depth of
soundstaging, and speakers disappearing. These are some of the effects that
Linkwitz experiences in his system, with its highly reflective room and his
equi-omni radiation pattern and his speakers pulled out into the room.

The speaker disappearing act is caused by a simple image shift toward the
reflected sound from behind the actual speakers. An aerial image is formed
in the region behind the speakers, getting the sound OUT of the speaker
boxes and creating the unmistakable impression of the musicians being right
there in front of you performing in your room, rather than sounding like
they are flat cartoons coming from the speakers and strung on a clothesline
between the speakers, with no depth or dimensionality. When done right, the
reflected sound that was recorded can seem to come from a broad set of
incident angles that are wider than the separation of the actual speakers,
lending the spaciousness that direct and reflecting speakers are famous for.
The combined effect gives the impression of the performers in front of you
along with turning your room into a model of the original hall, especially
when surround speakers are incorporated. If it is a tight and dry recording,
they are here. If it has some hall ambience recorded, they are here and so
is most of the acoustical environment of the original, displayed where it
belongs deep behind the performers and super wide beside and behind you.

You may have heard this effect with Quads, Martin Logans, MBLs, or even yes,
Bose 901s if placed correctly. I don't know if audiophiles think that this
effect is caused by point sourcedness, time alignment, or magic, but I am
here to tell you what does cause it and how to incorporate that into basic
stereo theory and perfect it.

Without an understanding of what causes all this three dimensionality and
speakers disappearing, you are just as liable to place your speakers right
up against the walls, or in the corners of your room, and never experience
what I am talking about.

I discovered it by accident and have been studying it for close to 30 years
now. You can fight me about it or study it further and try it youself, I
don't care, I'm just trying to explain something about genuinely audible
effects from an angle that has not been examined this closely before.

Thank you for your patience!

Gary Eickmeier, aka Chicken Little