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In the Forum: Horn-Loaded Speakers
In the Thread: Aporia - Silbatone Acoustics speaker
Post Subject: MTM and vertical hearingPosted by drdna on: 2/9/2009
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 Romy the Cat wrote:
However, in audio the coordinate system is not geometry but hearing and human hearing is not equally-dimensional. Humans, juts because the position of ears on heard have much higher sensitivity to horizontal sound source hen to vertical sound source. There is not such a sing as point source but there an array of point sources
A valid point but it has nothing at all to do with the reality of speaker installations where drivers are several inches wide and the distance from top to bottom is measured in feet. In the real world, the concept of the point source still has validity.


 Romy the Cat wrote:
I do not think that the point source installations have a distinct character because they are point source. They have distinct character because they are always shitty singe-driver souses. It is not geometry but the conceptually faulty premises, unless a mediocre and compromised result is accepted as satisfactory.
Not at all. I have taken two way speakers (tweeter+ two midrange) and moved the drivers from TMM to MTM D-Appolito configuration. There is a big difference in the sound presentation, which I attribute to the point source concept.

 Joe Roberts wrote:
I suspect that much of this effect arises from the perceptual disjunction caused by using sources of radically different type and character, accentuating the differences.
Likewise, I disagree based on my experiments as mentioned above. In any case, this "perceptual disjunction" might be heard as "instruments not sounding correct," etc. I am just talking about the simple fact that I can differentiate vertical positions when I listen to something. It is no great leap to say that a speaker that essentially totally ignores this fact will have a sonic signature reflecting this.

 Joe Roberts wrote:
All I am saying is that the notion of frequency dependent dispersion as raised by Jean Michel's paper is a relevant and often ignored or forgotten factor in system design. It may be that excessive narrowing is more obvious perceptually that excessive widening, hence more complaints about sharp beaming than the obverse. This topic brings with it the complicated issue of harmonics. A musical note is composed of a fundamental and various harmonics, with different radiation patters at each harmonic. Do we understand how our ears process the cues we get from this complex stimulus?
Reasonable enough, but I would again say that we should concentrate on the fundamentals first, and that a theoretical speaker that achieves esoteric goals at the expense of more fundamental ones may be suboptimal.

For such complex goals regarding harmonics and dispersion narrowing, we should focus on the measurements we can get in a speaker laboratory setting, as our hearing will not be able to give us adequate information. Big Smile

Adrian

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