Any research done on stereo speaker angles & dispersion?

I'm working on a project and wondering if there has been any research done on how the angle of two speakers inside a single cabinet affects dispersion and/or stereo separation in a room (or anechoic chamber...whatever).

Using this image as an example, how will various angles affect dispersion (with mono material) or stereo separation (with stereo material)?
Papers with measured polar responses, spectrograms (showing azimuth, frequency, and power), etc. would be ideal.

Have you checked AES.ORG?

There are a few articles in the AES E-library that may be relevant.
It's impossible to tell what kind of information and what type of results are present in any article given the brief descriptions.
I am not going to drop $20/ea. on several articles, among which I may find the equivalent of one or two relevant paragraphs.
I've already been through about 10 papers that looked promising from their descriptions, but ended up containing no real results or measurements.


I'm not slamming your suggestion; I do appreciate your help.
Hope there's no offense taken!

I should mention:

If someone knows of a paper/article that definitely has the info I'm after, I don't mind paying for it.
I just don't want to waste money on something that I cannot use.

There is an e-library membership at the AES for about $135 per year for members which gives you unlimited viewing.

Master handbook of Acoustics has some very good information on polar response / comb filtering / diffraction / etc. Mine is old but you can probably find it out there used cheap!

You'd also want to check out articles in regards to line arrays I would think. May have lots of relevant info.

This may help in some ways:

http://downloads.bbc.co.uk/rd/pubs/archive/pdffiles/monographs/bbc_monograph_52.pdf

http://downloads.bbc.co.uk/rd/pubs/reports/1963-01.pdf

The BBC papers have some interesting info which could lead one to potentially derive some supporting theories on the topic, but neither article has any experiments which directly relate to what I described above.

I can (and probably will) use some of this info in the proposal I'm currently writing, but I still need some measured results from an experiment with configurations similar or identical to the images above.
So, thanks for the links.

I've been researching this almost non-stop during the waking hours of the last four days, and have come up with absolutely nothing.
I'm starting to think that no one has studied this.
Surely not.

I would look for information on Allison Acoustics speakers. 

Gus, I actually found a paper written by Allison concerning soundfields in home listening rooms.
Although it does not specifically cover the area I'm trying to research, it does have a lot of useful info on dispersion and off-axis response in "real-world" environments.

I continue to look for more articles by Allison though.

I'm not sure if it would help for what you are looking for, but I can give some subjective comparisons with stereo guitar amps, and maybe even do some simple stereo recordings for you.  I have a Gibson GA-79RVT with 90-degree angles (but with a cut in the wedge) and a Guild S-200 and Ampeg ET-1 with 0-degree angles.  They are all semi-open back.

http://www.gibson.com/en-us/Lifestyle/Features/classic-amps-ga79rvt-0120/

http://www.ampsmith.com/guild_200s.html

this is not too hard to work out without having to do any experiments.

wavelength=speed of sound/frequency

1) Sound sources become more directional when the wavelength approach the dimension of the source. For large wavelengths (low frequencies) the sound source is virtually omnidirectional. For small wavelengths (high frequencies) the sound source is highly directional.

2) The smaller the wavelength in relation to the distance between the acoustical center of the sound source, the more destructive interference will occur between the sources. This interference is called combfiltering and is dependent on frequency. For distances shorter than 1/4 of the wavelength no destructive interference will occur. This is called coupling and will result in a summation with gain up to +6dB compared to one speaker only.

Think about this for a while and don't hesitate to ask again if you want me to explain in greater detail (pictures and stuff). Electro-acoustic system theory is my favorite subject. But I want you to understand combfiltering and coupling first.

/Anders

Sklyar is clearly well aware of combfiltering and coupling effects (I've never heard "coupling" used for constructive interference only for transfer of energy from one medium of propagation to another).

Actually, it might just be the right approach to apply the simple functions to derive the interference products, then build upon that expanding outward from the baffle plane, or junction of baffle planes into spherical propagation.

Skylar said:

Using this image as an example, how will various angles affect dispersion (with mono material) or stereo separation (with stereo material)?
Papers with measured polar responses, spectrograms (showing azimuth, frequency, and power), etc. would be ideal.

Click to expand...

I for one would find it very interesting to see these measurements, taken in an anechoic chamber, as a starting point. However, I suspect that most would conclude that the influence of any real world space would render the data less than meaningful for any practical application. Still, it's really surprising that no one has undertaken and published as an academic exercise.