What Kind Of Speakers Are Right For Me?
Point Source vs. Line Array vs. Column Array
There are many things to consider when looking into a new sound system for your church. One of the most obvious, and most important, things to consider is what type of speakers are best for you. This varies based on many factors, such as the style of worship you do, the acoustics of the space, the architecture of the space, and of course your budget. There are three main types of loudspeaker to consider: point source, line array, and column array. Each has its strengths and weaknesses, and all have their place, so let’s take a look at them.
Point Source
You may not have heard the term “point source loudspeaker” before, but they are probably what you think of first when you think of a speaker. They are typically a roughly trapezoidal box made of wood or plastic with between one and four drivers in it. They range from very small ( a box containing a single 3.5” driver) to fairly large (two 15” woofers, a 6.5” midrange driver, and a compression driver, all in one box). Point source simply means that each box acts as its own, independent sound generator. While multiple point source speakers may be used in conjunction with one another to provide good coverage, they are not dependant on each other to function correctly. This will make more sense as you learn how line and column arrays work in the following sections.
Point source speakers are available that can accommodate any type of sound source well, be it spoken word or a full contemporary worship band. The type of sound you wish to amplify mostly effects what woofer size you need. If you are a traditional church that only amplifies spoken word, an individual singing, and perhaps some soft prerecorded music, then you can get away with woofers as small as five or six inches. If you have a large band that includes a drum kit, bass guitar, and keyboards, then you’ll probably want to look into speakers with twelve or fifteen inch woofers, as they can handle the lower frequencies and higher volumes necessary for these instruments. You may even want to consider adding subwoofers!
When it comes to the acoustics of the space, point sources can be a mixed bag. While they are often the best solution, they may not work in some very reverberant spaces if their coverage patterns are not tight enough. Point source loudspeakers are available with different coverage patterns, typically described with a horizontal coverage angle and a vertical coverage angle, such as 90°x40°. When we design a system, we use these numbers to determine speaker placement to make sure that everyone can hear. These coverage patterns are only nominal estimates, however, and in reality different frequencies radiate differently. Low frequencies especially can spread out wider than the rating of the box, and these frequencies can build up in a very reverberant space, making everything sound muddy and indistinct. In spaces such as this, we can sometimes still correct problems with signal processing, but other times it’s better to consider another type of speaker.
Point sources can certainly be used in straightforward architectural spaces, but where they really excel compared to the other types is in spaces with odd architecture. If you have many small spaces to cover that are relatively isolated, this can be achieved with point sources by simply selecting a box with the right coverage pattern for each separate space. In fact, even when a line array or column array is chosen as the main sound system, it is very common to still use some point sources as fill speakers to supplement the coverage.
Another reason point sources are very popular is their cost. Because of their relative simplicity and low driver count, point sources systems are available starting at a very low cost, with options available for any budget at all. Even in spaces that would be well served by a line array, a well-performing point source system is often available at a fraction of the cost.
Line Array
Line array systems may not be what you think of first when you think of speakers, but if you’ve been to a large concert in the past twenty years, you have probably seen one. Line arrays are comprised of multiple copies of the same speaker box hanging together vertically. The individual boxes can range from small, two-way boxes, to large three- or four-way boxes. Hanging them together in an array allows the boxes to “acoustically couple” which provides more directional control over the sound over a wider frequency range. This basically means you can “aim” the sound better than with a standard point source box.
As for sound sources, line arrays are best suited to wide frequency, high volume sources, such as bands that feature drum kits, bass guitars, and keyboards. In live concert applications they are usually supplemented with subwoofers, but even without them, large line array systems can output quite low frequencies at impressive volumes. While they do have advantages in directivity that may still make them an appropriate solution in some cases, we would generally consider them overkill for churches that have more traditional styles of worship comprised mostly of spoken word, singing, and acoustic accompaniment.
When the acoustics of a space are considered, line arrays are valuable for the control that they offer. By aiming an array to cover only the audience, you can avoid excessive reflections that can muddy up a very reverberant space. While point sources can also be aimed to minimize these reflections, line arrays are better at controlling the low frequencies that can be particularly problematic, lending them an edge in difficult spaces that still need full-range sound.
Architecturally, line arrays are best suited to large, open spaces. Due to their nature, they require fairly high ceilings to even be an option, as a minimum of three or four vertical boxes is required to begin to have the advantageous control they offer, with systems ranging as high as twenty-four boxes in a single vertical hang. In addition to this, complex spaces that can not be easily covered by one main hang or pair of hangs will prove difficult to cover. If most of a space can be covered from the line array, small fills can be done with point source speakers.
Finally, we come to budget. Line arrays can provide world class, tour grade sound to your church, but that usually comes with a hefty price tag, relative to other loudspeaker types. The individual boxes generally cost as much as nice point source boxes, but the problem is that you need many of them. On top of this, they require more amplifiers than other systems to power all the boxes. Due to the necessary engineering needed to design a functional line array, there are not really many budget options available. That said, line arrays have been around long enough now that they are offered in many sizes, and advances in driver technology have increased the performance of smaller woofers. Compact line arrays can provide all the control and directivity of a line array system in a smaller, more affordable package that can still deliver the low end you need.
Column Array
Column arrays apply the same “acoustic coupling” principles as line arrays on a smaller scale, within one speaker box. While they have been around for decades, advances in driver and signal processing technologies have reinvigorated these designs in the past fifteen years, providing a host of new solutions that vastly outperform old column arrays. Column arrays employ many of the same small woofer in a vertical line in one speaker box, typically between eight and twenty-four 1.5” to 6” drivers. This gives them a very wide horizontal coverage angle and a very narrow vertical coverage angle, and sort of makes them a hybrid of line array and point source loudspeakers.
Despite the advances in driver technology, column arrays do not typically provide a robust enough low end to handle live music with contemporary instrumentation. They are best suited to more traditional styles of worship, and excel in spoken word, singing, and light prerecorded music. Some systems are available now that pair column arrays with subwoofers to achieve the low end needed for live music, but these are still only suitable for smaller spaces.
Column arrays perform very well in places that may not have ideal acoustics. The tight vertical pattern control they have reduces the amount of unwanted energy reverberating around a very live space. Reducing the reverb allows speech to remain clear. Column arrays can also be deployed as delay fills in addition to the mains to provide an exceptionally consistent volume throughout the space, while still mitigating troublesome echoes.
When it comes to their performance in various architecture, column arrays perform best in simpler, open spaces. They particular excel in very wide spaces, as their horizontal coverage patterns tend to be much wider than most point source boxes, sometimes reaching 170°. This means a single column speaker can often cover what would have required two point sources side by side. Column arrays also lend themselves to fairly discreet installations, as their tall, slender boxes are much less bulky than point source boxes, and are much smaller than even the most compact line array system.
As for budget, column arrays will not break the bank. The high driver-count per box is somewhat offset by the small driver size and lower power-handling requirements, keeping it fairly similar to the cost of a point source system. Furthermore, there are a few budget models out there. They tend to not have quite the performance of higher-end systems due to cheaper components, but can still be an improvement over point sources in the right situation.