Your Summit X’s launch a 30 degree horizontal disper-
sion pattern. This horizontal dispersion field gives a
choice of good seats for the performance while minimiz-
ing interactions with side walls (see figure 9). Make sure
both spe akers sta nd exactl y at t he same vertical angle,
otherwise the image can be skewed or poorly defined.
The wave launch of both speakers is extremely accurate
in both the time and spectral domain. Consequently,
small refined adjustments can result in noticeable sonic
improvements.
Controlled Vertical Dispersion
As you can see from the illustrations, your Summit X
speakers project a controlled dispersion pattern (see fig-
ure 10). Each Summit X is a 44 inch line source beginning
15 inches above the base. This vertical dispersion profile
minimizes interactions with the floor and the ceiling.
It is a known fact that as the sound wave becomes pro-
gressively 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 exhaustive testing of many different methods, we
conceived an elegantly simple, yet intensely hand craft-
ed 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 pat-
tern of our transducers.
Three Major Types of Dispersion
Figure 5–6. 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 consequent-
ly confused and blurred.
Figure 7–8. 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.
Figure 9–10. A controlled 30 degree cylindri-
cal wave-front, a MartinLogan exclusive, offers
optimal sound distribution with minimal room
interaction. The result is solid imaging with a
wide listening area.
Controlled Horizontal Dispersion
Dispersion Interactions 15
dIsPersIon InteraCtIons