MartinLogan The Quest Speaker System user manual Three Major Types of Dispersion

Three Major Types of Dispersion

In the field of loudspeaker design, it is a known fact that as the sound wave becomes progressively 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 why most 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 these different solution attempts, we found an elegantly simple, yet very difficult to execute solution. By curving the radiating surface, we create the effect of a horizontal arc. This allows the engineers at Martin-Logan to control the high frequency dispersion pattern of our transducers. That is why you see the gentle curve on our products.

Multiple Large Panel Dispersion

Even though they suffer from "vene- tian blind" effect, angled multiple panel speakers can deliver good imaging, but only to specific spots in the listening area.

Traditional Point Source Dis- persion

As can be seen, point source con- cepts invite a great deal of room inter- action. While delivering good frequency response to a large listening audience, imaging is consequently confused and blurred.

Curvilinear Line Source Disper- sion

Acontrolled 30-degree cylindrical wave-front, which is a Martin-Lo- gan exclusive, offers optimal sound distribution with minimal room interac- tion. The result is solid imaging with a wide listening area.

Quest User's Manual Page 17