A mere decade ago, modular line arrays were essentially nonexistent as the primary sound reinforcement system in worship auditoriums. Over the past five years, however, line arrays have mushroomed into the hottest trend in loudspeaker systems – to the point where traditionalists might label it a fad, Unquestionably the change is apparent in the pages of this publication. By intention or not, it seems most of the AV systems profiled recently have shown photos of the near-ubiquitous, gently curved “banana” of line array loudspeaker systems.
But is a line array always the best solution for your new, refurbished, or expanded worship auditorium? It all depends, according to leading audio system designers surveyed by Church Production. But, before we get to their cogent analysis, we'll first review how line arrays differ from conventional or point-source systems.
Go Bananas – or Not
In its simplest terms, a line array is a vertical stack of loudspeakers deliberately designed so that the sounds from the separate loudspeaker cabinets combine, or interact. This has two benefits: it controls the vertical coverage, and also throws sound farther than is possible with conventional loudspeakers. Almost counter-intuitively, the longer the line array, the more the vertical coverage is restricted – or “flattened out” – across the audio spectrum. Essentially, the line array creates a uniform, wide (usually 90 to 120 degrees) wavefront that is squashed into a flat wedge of sound. Ideally it will push the same volume level nearly twice as far as with conventional designs. However, following the strict laws of physics, to make this work at lower frequencies you need a long line array. For example, for pattern control down to 125 Hz (about low C) you need a line array over nine feet long.
The alternatives are conventional loudspeakers, also called “point source” or “point and shoot.”
These systems are designed so that the sounds from separate cabinets do not interact, even if arrayed or clustered adjacent to each other. Each cabinet works like an individual sound “spotlight,” and if arrayed you'll often see significant splay angles in between to prevent patterns from overlapping. In this case, overlap causes undesirable “hot spots” and “dead spots.”
An Obvious Case
If you want to throw powerful sound over a distance, and your audience is all on one relatively flat plane, then a line array is clearly your best solution. A case in point: outdoor music festivals, the louder ones in particular. For the main system, nothing else makes sense. However, the less your worship space resembles a festival layout,, the more you may want to consider the alternatives.
“In a room that is quite wide but not very deep, line arrays tend to be more expensive and not work as well,” explains Ryan Knox, a senior consultant at Acoustic Dimensions in Dallas, Tex. “The other place they tend not to work so well is when you have a large vertical angle of coverage, such as with high balconies. In tall rooms, you may need a lot of line array boxes to cover what you could with two or three conventional ones. Line arrays work best with a fairly narrow opening angle.”
Brian Masiello, senior consultant at Acentech in Cambridge, Mass., adds: “Line array systems typically have wide horizontal coverage, so they may not work well in a very narrow room. In some cases, a point-source cluster is a better solution, as the horizontal coverage can be tailored using the coverage patterns of multiple loudspeakers.”
Hitting the Ceiling
Although long line arrays can offer better low-frequency control, sometimes there simply isn't space to enjoy the benefit. “At times we just don't have the trim height to make a line array a viable option,” relates George Clark of Clark Pro Media in Alpharetta, Ga. “By the time you have lighting, projectors and screen positions, you may find no room in the vertical plane to work with. If you don't have the height to cover the room correctly with a line array, point source boxes might be the better solution.”
John Fuqua, vice president All Pro Sound in Pensacola, Fla., cites a recent experience. “We recently completed a major renovation of a large church, where they knocked out a side wall and went from 800 to 1800 seats. But they kept the same 20-foot ceiling. Line arrays would have been the best option for the increased depth of the room, but with the low ceilings we instead used a ringed distributed system with a main ring, a delay ring, and front down-fills, all conventional cabinets.”
Line arrays also could prove problematic if you want to go beyond mono or, at most, stereo program playing in the room. According to Acoustic Dimensions' Knox, “Once you start looking at LCR [left-center-right] or multichannel, the scenario changes. If you can't cover the full width of the room with one array, you can have problems, because line arrays don't work well angled right next to each other. So you have to use conventional fill boxes, and at some point you're simply better off going with all conventional systems.”
In other cases, continues Knox, the room simply becomes too small, with throw distances too short for line arrays to make sense – as in the case of chapels. “In smaller rooms, conventional speakers can perform as well as the mini-line arrays,” he says, “with less system complexity and lower overall cost.”
Comparing Costs
But why do line arrays cost more? By their very design, modular line arrays require stacking multiple cabinets at each loudspeaker location. “High quality line array systems typically cost more because you are using more loudspeakers, rigging and processing,” observes Bill Schuermann of HFP Acoustical in Houston, Tex.
Acentech's Masiello adds, “In some projects, a line array initially seemed the obvious solution. However, once we started to look at pricing, we could see that a point-source solution would be more cost-effective and still provide high quality sound.”
The type of program material in worship – the balance of speech and music, as well as the music style – also has a bearing on which technology is your best choice. “Some of it is perception, but it is generally accepted that line arrays give a stronger, more ‘in your face' sound quality that suits contemporary music styles,” surmises Ryan Knox. But that doesn't mean conventional approaches can't be strong performers as well.
“We designed a system for a 2,000-seat Baptist church,” recalls HFP Acoustical's Bill Schuermann, “and used point-source systems because of budget, space considerations, and to keep cabinets close to the catwalks. It still gives the church the 100 dB-A that they required for their music program, and the speech intelligibility is excellent.”
Steady Improvements
Though new line array systems tend to hog the media spotlight, steady incremental improvements in point-source systems continue to make them an appealing alternative for audio designers.
“There have been no big game-changers in the past decade,” contends Knox. “But for one thing, the packaging has definitely improved. We have new, sleek cabinets that are easily riggable, so they can be exposed without the old ‘flying junkyard' effect.”
Additionally, systems designers now have more flexible options for improving performance and solving problems. “Manufacturers are taking some of the lessons learned from creating focused patterns for line arrays and applying them to horizontally arrayable point-source clusters,” notes Schuermann. “Also, acoustical modeling programs are getting better, as is loudspeaker data for plugging into them. That translates into better accuracy and performance in ‘point-and-shoot' systems.”
Masiello, too, welcomes the plethora of options he now has for custom-tailoring system coverage. “The horizontal/vertical coverage options have greatly expanded. Additionally, more manufacturers are providing these options in rotatable horns. If the architecture of a space prevents me from mounting a loudspeaker in one orientation, I have the flexibility to rotate the horn instead of the cabinet.”
George Clark also concurs on the improved horn designs, and adds that systems have further benefited from “the trend toward advanced network and DSP control, which more manufacturers are now providing for fine-tuning the systems.”
Tooling Up for Tomorrow
In the final analysis, a good system designer will propose a system that best transmits the full content of your worship service throughout your space, and does so within your budget. That could mean hanging line arrays or using distributed point-source systems – or a combination. For example, Schuermann points out, “I regularly use front-fills in all of my designs, regardless of the main speakers. And front-fills are point-source systems that are important in maintaining acoustical imaging in the room.”
Some designers are wary of following the latest trends, and prefer to rely on time-tested approaches. Among them is Bill Thrasher of Thrasher Design Group in Kennesaw, Georgia. “To date I have not seen but one or two of the largest church situations in which line arrays were actually appropriate,” he maintains, “and that includes churches I have visited that are currently using them. I've seen considerable problems from using them, and in my opinion they are just plain wrong for most churches.”
Other designers, though also wary of trendiness, tend to steer a middle course. All Pro Sound's Fuqua takes a broad view of the technology landscape: “We still feel that, with the continued development of line array technology, and now digitally steerable array technology, that conventional systems are a viable solution in many applications. When they work well, point-and-shoot components always should be considered.”
Or, as Masiello summarizes, “Loudspeakers are simply tools. You have to know how to use them, and decide which one is best suited for that particular job.”
