Large outdoor locations catering to thousands of people require sound that can overcome crowd noise and the sounds produced by the activities themselves. Think of racetracks, air show tarmacs, transit stations, theme parks, college campuses, or any other outdoor location where noise and physical characteristics create challenges for audio system designers. And, in almost every type of outdoor facility, highly reverberant acoustics and widely varying noise levels present significant obstacles.   

Regardless of underlying noise and structural variables, audio systems must be properly designed and installed so that the voice reproduction that has to be heard—such as event announcers, train station arrival and departure updates, and emergency communications—is broadcast clearly and intelligibly.

Obviously, of paramount importance in any properly functioning outdoor audio system are the loudspeakers that produce the output.

But what are the critical factors that determine loudspeaker effectiveness in outdoor settings? Here are several to consider:

Throw distance

It’s a common misconception that the “throw” (i.e., the capability of a loudspeaker to project sound at a distance) is all that has to be considered when designing an outdoor loudspeaker system. A “short throw” system covers the areas nearer to the loudspeaker and a “long throw” speaker system is used to cover the areas farthest away from the loudspeaker. For example, a college sports stadium with audio broadcast from atop the press box is a job for a “long throw” horn or system.

Martin Stadium at the University of Tennessee uses Biamp loudspeakers, shown atop the press box.

This concept works fine in systems with limited bandwidth, which is typical of a public address or voice communications system in an outdoor grandstand, or in touring rigs where the massive size of the speaker system is the dominant factor. But where the concept falls short is in situations with a single loudspeaker or a small cluster of loudspeakers in a facility where the same frequency response and sound quality is needed in all the seats both near and far. In a large-scale sound system that is required to deliver music to all the seats, like a large church, or auditorium, the issues of maintaining a balanced sound through the seats makes this much more complicated than picking long and short throw speakers.

Directivity

In a loudspeaker system, the directivity is an indication of how effective the speaker is at taking the sound it produces and sending it in one particular direction instead of all directions. A loudspeaker that is a high directivity device is commonly called a “long throw” device. Loudspeakers in this category are called projectors and horns. A loudspeaker with low directivity is a “short throw” device, often called a point source loudspeaker.

Weather-resistant construction

In most outdoor installations, loudspeakers must be built to withstand extreme weather conditions. Strong winds, high humidity, extremely hot or cold temperatures, and rainfall—or any combination—should be considered to ensure the appropriate loudspeakers are chosen for the location’s typical weather conditions.

Visit our “Sports and Entertainment” page to learn more about the many industry-leading Biamp loudspeakers available for outdoor applications.

Source: MC2