(Thanks to Chris Pyron for his contributions to this story)
When looking for a new PA for your church’s worship center, sanctuary or children’s space, there is no shortage of loudspeaker options. While the abundance of choices may seem overwhelming, they can be broken down into three basic types of PA systems—point source, vertical line arrays and column loudspeakers. Each style offers particular advantages for different music and speech requirements, room types and architectural styles.
Before examining the advantages and disadvantages of each kind of speaker, it’s important to weigh certain key considerations.
- The size and shape of the seating area that requires sound coverage
- The degree of focus on music and the types of music the system needs to support
- Gauging and maximizing your system’s gain before feedback (GBF)
- The architecture of the space and the need to focus sound away from acoustically reflective areas
- Aesthetic concerns and sightlines
POINT SOURCE SPEAKERS
“Point source,” “point-and-shoot” and “traditional” are common ways of referring to the same kind of loudspeakers. They are typically rectangular, come in a variety of sizes and usually contain a horn designed to cover a specific vertical and horizontal angle. They are often used individually, but can be arranged as part of a larger array or cluster.
Advantages of Point Source Speakers
Versatility of Size and Deployment – Point source speakers can be a great option when room dimensions, aesthetics and budget need to be taken into consideration. They are available in a variety of sizes and provide PA system solutions for many kinds of worship spaces. Some of the smaller models are portable and floor standing, so they can be moved around as needed. Often, point source speakers can be concealed and still correctly deployed.
Pattern Coverage – Point source speakers achieve pattern coverage based on their size, with the size and shape of the horn primarily being the determining factor, dictating how wide or how narrow the mid and high frequencies cover. The bigger the horn, the better the pattern control. Many times, the pattern control of traditional cabinets is all that is needed for small- to medium-sized rooms. Most people’s experience with point source speakers involves systems that use small cabinets with small horns, but various size options are worth exploring.
Horizontal Coverage – With point source speakers, the horns are capable of controlling the horizontal as well as vertical coverage. Vertical line arrays and column speakers tend to provide good control of the vertical coverage, but provide a predetermined horizontal. Depending on the aspect ratio of the room and the horizontal reverberation character of the space, point source speakers can perform better than a line array in this regard.
Expense – Because there are fewer individual enclosures and each box contains fewer components, point source speakers are often more cost-effective than line arrays.
Disadvantages of Point Source Speakers
Low-Frequency Limitations to the Pattern Control – Point source speakers are generally shorter (smaller vertically) than line array systems, so their vertical pattern control for low frequencies doesn’t extend as low in frequency as with line array systems.
Arraying Challenges – It takes skill to design a good array with speakers that are dual-purpose, designed both for individual use and for arraying. Arrays may work better at some frequencies than at others, resulting in acoustic lobing at some frequencies as well as interference at the seams between the coverage patterns of the multiple cabinets. For example, a common configuration for point source speakers (called “long-throw/short-throw”) has a top narrow loudspeaker projecting toward the back of the church tight-packed to a bottom wider-coverage loudspeaker for the closer seats. Unless designed with an eye toward the real beamwidth characteristics of each cabinet at each frequency, this can result in unexpected interference between the two loudspeakers. This is why a skilled sound engineer is recommended when arraying point source speakers.
Throw Distance – Depending on the depth of the church, sometimes point source speakers cannot project all the way to the rear area, so delay speakers are occasionally installed partway back to augment the frequency response for the rear seats. This arrangement, however, can also result in inconsistencies within the listening space, because mid and low frequencies from the delay speakers can wrap around the typically small cabinets and interfere with the clarity at the front of the room.
VERTICAL LINE ARRAYS
A vertical line array is what you are likely to envision at a large concert environment with a long J-shaped series of speakers suspended on either side of the stage. In the past 10 years or so, vertical line arrays—systems with multiple cabinets (each with multiple drivers) arranged in a vertically connected configuration—have gained popularity with large venues.
Advantages of Vertical Line Arrays
Preventing Drop Off With Distance – A major advantage of a line array system is that you can achieve much more consistent sound levels from the front to the back of the listening area. Line arrays are made up of multiple modules, so by adjusting the physical angle and the amplitude of individual modules, a higher sound level can be projected toward the back of the room than toward the front, resulting in more consistent coverage throughout the space.
Vertical Pattern Control – The taller the line array, the better the control of the vertical coverage of the low frequencies emitted from it. This is important, as it reduces how much sound is sent toward the ceiling, which can cause unwanted reflections back into the listening areas. They can also reduce the amount of sound that leaks onto the stage or chancel area, which in turn, decreases the level of sound regenerated through open mics on stage, thereby cleaning up the overall sound and increasing GBF.
Sound Pressure Level (SPL) Capability – Some line array systems have a large number of drivers inside each cabinet of the array, allowing a single coherent wave front to be produced. Because of all these drivers, line arrays often have the capability of producing a higher SPL than is required, enabling systems to operate well below their stress point. If your church’s worship style requires concert-level sound reinforcement or hosts visiting national acts, the SPL capability of certain line array models can be an advantage.
Disadvantages of Vertical Line Arrays
Shallow Rooms – While line array systems can project sound long distances, they may not be a good fit for rooms that are shallow. The coverage requirement of a horizontal room can sometimes be difficult to match with a vertical line array solution.
Height Requirement – Line arrays require substantial vertical height to achieve pattern control. If there is not enough height for the line array to be very tall, vertical pattern control can be lost, allowing low and mid frequencies to project to the ceiling and stage, causing unwanted reflections or reduced GBF at the stage area.
Sightlines – Another height consideration is sightlines. It’s important to consider that depending on the shape of the room, a tall array may obstruct congregants’ view of video screens or the stage area.
Expense – The price of a line array may exceed budget requirements. Line arrays consist of a large number of modules with a larger quantity of drivers. This can be a major point of consideration when budgeting and designing a PA system.
COLUMN ARRAY SPEAKERS
Contemporary column speakers function similarly to line arrays. They also feature multiple drivers, arranged vertically, but take the form of a single narrow cabinet.
Since the middle of the last century, column speakers have experienced long periods of popularity in houses of worship because of their high degree of pattern control. This allows for greater clarity, especially in cathedrals with cavernous designs and many reverberant surfaces. After falling out of favor for a while, though, column speakers have recently experienced a resurgence of popularity due to updated technology and expanded performance capabilities. They have since expanded, to some extent, into more contemporary worship spaces.
Advantages of Column Array Speakers
Aesthetics – Regardless of the type of column speaker, they can be a great option when aesthetics are a concern. Because of their narrow width, they are easily integrated into traditional churches and other spaces where the visual impact of a loudspeaker system must be kept to a minimum. Their shape also makes them suitable for mounting on architectural columns.
Coverage – Passive column speakers are a cost-effective way to provide vertical pattern control. Certain models offer an extended bass response, and there have been recent advancements in passive column speakers that allow users to adjust coverage patterns, to some degree, to better match the shape of the listening space. Passive column speakers tend to be preferable for outdoor applications, simply to protect against exposing AC power to the elements. They can be a good choice for outdoor overflow or reception areas.
With powered column speakers, the coverage is adjusted electronically, typically from a remote computer. “Steered” aiming adjusts the direction of the coverage, while more complex “Shaped” aiming precisely covers complicated architectural configurations, such as balconies and multiple raked seating planes. Better and more precise aiming provides increased speech intelligibility—and music clarity—everywhere in the room.
Consistent Sound Levels Front-to-Back – Like full-sized vertical line arrays, column speakers are capable of producing consistent sound levels from the front to the back of the listening space, but without cumbersome multiple enclosures.
Affordability – Housed in a single enclosure, the cost of a column speaker tends to be much lower than vertical line arrays. The reduced number of amplifier channels needed to drive most passive column speakers and the built-in amplifiers inside the powered column speakers help make column arrays a more affordable option in terms of total system cost.
Disadvantages of Column Array Speakers
Passive Column Aiming – Passive column speakers typically have to be aimed physically, by tilting the column on the wall. The acceptability of having a down-tilted speaker is an aesthetic consideration.
Volume – Column speakers don’t tend to be as loud as full-size vertical line arrays.
Bass Output – Column speakers also tend have less bass output, although that’s not always the case. If more bass is required, subwoofers can always be added to the system.
Shallow Rooms – Like with large vertical line array systems, column arrays provide less horizontal pattern control than point source speakers.
Point source speakers, vertical line arrays and column speakers each have a valuable place in the toolbox of designing sound systems for houses of worship. A thorough analysis of your environment helps ensure a system that will capably serve your congregation for years to come.
Do you use point source, line array or column speakers in your church? Share your insights in the comments.