Editor’s note: This article originally appeared on PSW in 2012, however the information is still quite relevant and worth revisiting.
I’m asked a lot of questions about sound. Many of them focus on unraveling and understanding some particular function, feature or concept, while others are directed toward distilling my opinion on methods or industry trends.
A while ago. I was asked some questions that led me to some in-depth pondering. The questions: Why are line arrays so popular? Are they a fad or here to stay? And what will be the next big thing?
The fact is that line array-type systems have taken the professional sound reinforcement industry by storm. Nearly every manufacturer offers several choices.
But just what is it about line arrays that have positioned them to completely dominate the industry? Is it just a gimmick or is there truly some aspect of the vertical configuration that offers an inherent advantage over other system types?
Stepping back and taking good long look, I found that there are several properties these thinner line systems possess that are readily apparent, plus one substantial advantage in particular that is not so obvious at first but perhaps most important of all.
Just to keep things interesting, and hopefully clear, I’m going to examine the basics of sound system design from a slightly different angle than perhaps is common.
In The Zone
A conventional and intuitively logical approach is to deal with a large acoustic space as a set of smaller zones. To cover the area, one constructs clusters of loudspeakers, each aimed at a particular region or zone. Each loudspeaker box in the cluster can then be optimized in terms of EQ and volume.
With this approach – which I will call “zonal coverage” – it’s advantageous to minimize the overlap between the box-to-box coverage patterns. The goal and challenge for the system designers and technicians setting up the system is to try to achieve smooth sonic transitions from zone to zone.
This system is constructed such that listeners are not exposed to sound emanating from boxes that are in close physical proximity to each other and at different distances. More simply put, sound from multiple sources arriving at the ear at differing times equals “not so good.”
When projecting sound over varying distances, some issues arise. The coverage area of each box increases in size with distance, meaning the angles between boxes pointed far away should be increased.
Yet volume naturally drops with distance, so to maintain volume at distance, the inclination is to decrease the angles between boxes in order to have more of them pointing at the far-away zone. As a result, zonal coverage systems often employ longer throw, narrow dispersion loudspeakers to help solve the dilemma.
Electro-Voice X-Array, NEXO Alpha, and Turbosound Flashlight and Aspect loudspeaker systems are all excellent examples of zonal systems. Much effort was put into these loudspeaker designs, in order to achieve distinct and consistent vertical and horizontal coverage projected from each individual box. Usually, they employ relatively few drivers in each box, with horn-loading assisting with pattern control.