Dispersion Interactions; Controlled Horizontal Dispersion; Controlled Vertical Dispersion; Three Major Types Of Dispersion - MartinLogan classic ESL 9 User Manual

D IS PE RS I O N I NT E R A C T IO N S

Controlled Horizontal Dispersion

Your speakers launch a 30 degree horizontal dispersion pat-
tern. This horizontal dispersion field gives a choice of good
seats for the performance while minimizing interactions with
side walls. Make sure both speakers stand exactly at the same
vertical angle, otherwise the image can be skewed or poorly
defined. The wave launch of both speakers is extremely accu-
rate in both the time and spectral domain. Consequently,
small refined adjustments can result in noticeable sonic
improvements.

Controlled Vertical Dispersion

As seen in the illustrations, your speaker project a controlled
dispersion pattern. This vertical dispersion profile minimizes
interactions with the floor and the ceiling.
A controlled 30 degree cylindrical wave-front,
a MartinLogan exclusive, offers optimal sound
distribution with minimal room interaction. The
result is solid imaging with a wide listening area.
As can be seen here, point source concepts
invite a great deal of room interaction. While
delivering good frequency response to a large
listening audience, imaging is consequently
confused and blurred.
Even though they suffer from "venetian blind"
effect, angled multiple panel speakers can
deliver good imaging, but only to specific spots
in the listening area.
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Three Major Types of Dispersion

It is a known fact that as the sound wave becomes progres-
sively smaller than the transducer producing it, the dispersion
of that wave becomes more and more narrow, or directional.
This fact occurs as long as the transducer is a flat surface. Large
flat panel speakers exhibit venetian blind effects due to this
phenomenon. This is one reason why many manufacturers opt
for small drivers (i.e. tweeters and midrange) to approximate
what is known as a point source wave launch.
Historically, most attempts to achieve smooth dispersion from
large flat panel transducers resulted in trade-offs. After exhaus-
tive testing of many different methods, we conceived an
elegantly simple, yet intensely hand crafted process. By curving
the radiating surface, we create the effect of a horizontal arc.
This allows the engineers at MartinLogan to control the high
frequency dispersion pattern of our transducers.