Small Church Big Sound
Do you think that only big churches with a large budget can have good sound? That’s not true! Naturally, you do get what you pay for… but with the proper analysis and configuration, you can have a good sound system without breaking the bank! Most sound installation companies only want the “big” jobs and will not even provide a quote for smaller congregations. Here we will give you great options on how to get the best sound system even if you have a small budget.
Good speaker coverage is one of the most important aspects of setting up a successful live sound system, yet it’s one of the most nebulous concepts. A discussion about proper PA coverage with three seasoned live sound engineers is likely to yield three different approaches. The goal is to adequately and evenly cover your entire audience with the PA system.
Although there are formulas that can help you calculate proper coverage given controlled circumstances, conditions created by room shapes, ceiling heights, the presence or absence of walls, and many other factors combine to render the process of providing adequate speaker coverage as much an art as a science. If your coverage is truly suffering, making sure the main boxes hit the back seats and adding small downfills to cover the front rows would be an easy way to accomplish what is needed. You will want to invert the top boxes so that the HF of the mains and downfill boxes are as close as possible to get the acoustic seam between the two easily lined up.
You’ve just purchased new loudspeakers for your church praise band or for a public address system in your church hall. Now you need a power amplifier to drive them. How much power do you really need?
The answer to that often-asked question depends on several factors. How much power can your speakers handle? How efficient are your speakers? What is the room size? How loud do you need to be? And, what is the type of program? A simple speech system can get by on much less power than a full-range system for music and chorus.
Most system designs start with the speakers. Speaker selection is actually the most critical part of the system design. Their frequency range, coverage pattern, and power requirements basically determine the amplifier requirements. Most loudspeaker manufacturers give two figures for power handling: continuous and peak. A reasonable amplifier rating will fall between these two figures. Thus, a speaker rated at 200 watts continuous and 800 watts peak should operate safely with a 400-watt amplifier.
Speaker efficiency is another critical factor. Speakers have a “sensitivity rating” which tells you how much sound comes out when using a standard input power. A more efficient speaker delivers more sound for a given wattage. Every increase of 3 dB in a speaker’s sensitivity is equivalent to a “free doubling” of your amplifier power. For example, to produce the same sound level, a speaker with a sensitivity rating of 94 dB requires twice the power of a speaker rated at 97 dB, and four times the power of a speaker rated at 100 dB. However, more efficient speakers often sacrifice smoothness to “cut through” better. Therefore, a medium efficiency speaker, coupled with a somewhat more powerful amplifier, may be the best choice.
When considering room size, you will need two to four times the power to fill a space that is twice as long. If a 100-watt system sounds good in a small church, a church with twice the length will require 200-400 watts to maintain the same sound level in the back. Keep in mind, however, that large spaces need speakers with special “coverage patterns” to protect the people in front from excessive sound levels. A professional audio consultant can be hired to design a system that ensures even coverage, but one basic rule is to mount the speakers as high as possible, so some of the sound travels over the people in front in order to reach the back.
Most speakers reach a point of diminishing returns at about 400 watts. If you need additional volume, you will likely need to add more speakers, and their coverage patterns become even more important.
Remember that the dynamic range of today’s audio source equipment is extremely high. The amp that you select must be capable of handling the program peaks without clipping, but the system must be protected against severe “blasts” of sound. Many amplifiers offer clip limiting features which protects against the worst peaks. The signal chain feeding the amplifier should also have some sort of program limiter to protect both the system – and the congregation’s hearing – from unintended bursts of sound.
Anyone that has run live sound in church knows the inherent challenges all too well. Small churches with little budget for sound equipment often struggle to do an adequate job of supporting the contemporary sound of rock and gospel inspired worship music. Doing a great job is often beyond the expectations of most church staff, but it is possible with a little budget and a lot of know-how.
One of the biggest things we need to in mind is: Intelligibility Is The Key.
Anything that draws people’s attention away from their purpose for being there, away from the presence of God, away from the words they are singing and what they mean is detrimental. So if people can’t understand the words being spoken or sung, we’re missing the point as sound engineers. This is obvious when it comes to the pastor’s microphone, but it is essential during the worship music as well.
Here are the things we’ve found that help intelligibility.
1. Roll off the low end on everything that doesn’t NEED it.
Kick, Bass Guitar, and Floor Tom are a few of the instruments that do need it. Everything else just muddies it up. Use the high-pass or low-cut filter on your mixer, and if there is also a low frequency EQ, lower the level of that as well for channels that don’t need the low end.
2. Take out the low mids on channels that don’t need it.
This is especially important for churches that meet in high school gyms, as the low mids tend to be very muddy and this adversely affects intelligibility.
3. Take the lows and low mids out of the monitors as much as possible.
Anything with lots of low end that needs to be heard and has low energy can already be heard by the performers naturally (drums), through an amplifier (bass guitar), or through the PA since the low end of the sound spectrum is not directional.
4. If you have the chance to use subwoofers, do it.
I’m not saying you should make your worship band sound like they are being played by your neighborhood high school kid with 10 subwoofers in his car. Rather, subwoofers enable you to get adequate low end without killing your main PA speakers to do it. Low frequencies at high volumes actually move the speaker cones enough to cause phase shifts in the mid range frequencies reproduced by the same speaker cone. This can make the mids sound hollow, adversely affecting intelligibility. Using subwoofers for your low end results in longer lasting, better sounding main PA speakers.
5. Use a crossover/delay processing unit before going to the amplifiers and speakers.
This allows for a lot of control over the sound and enables awesome things like using an aux send to control the level of each channel that goes to the subwoofer(s) independently. Turning up the aux send feeding the subwoofer for the Kick, Floor Tom, and Bass in the choruses of a song, for instance, can enhance the dynamic range of the sound in a very musical way.
6. Compressing vocals is vital.
Drum compression is often popular, but in most small church settings it’s not necessary. Since the drums are already the loudest thing happening, sound engineers in small churches really don’t need to augment the live drum sound much (if at all) in the PA, outside of maybe sending the Kick drum through the mains and subwoofer(s). Compressing vocals enables the engineer to spend less time trying to make sure a vocalist’s words can be understood, and more time enhancing the worship experience by building on the worship that is already happening on stage. Many vocalists talk much louder than they sing- compression means not having to worry so much when they go back and forth.
7. Use an aux send for reverb and return it to an open channel instead of an aux return
(just remember not to turn up the aux send for reverb on that channel AT ALL!) By routing reverb this way you get a handy fader and mute button for the reverb signal, so you can easily mute the reverb when vocalists are speaking for a portion of the service, then bring it back in when they start to sing.
8. Make sure your vocalists understand basic mic technique and the way their microphone picks up sound.
Nothing annoys the sound engineer and congregation more than a hapless vocalist that holds the mic at their navel and sings in a whisper. Having vocalists that cover part of the microphone’s capsule can cause the cardioid pattern in some mics to become omnidirectional because of the techniques used to make the microphone directional. Unless they are beat-boxing they should stay away from doing this. And, of course, they should know which end of the microphone to point at the monitor, and which end to NOT point at the monitor. It sounds elementary to sound engineers, but that is the level of knowledge some vocalists have about microphones, especially at church.
9. Gating/expansion is helpful for vocal mics too!
Gating is popular with live sound engineers for drum mics, but it’s cousin, expansion, can be even more useful for vocal mics in many situations. If people use proper mic technique an expander on each vocal channel can help reduce the potential for feedback. Leaving mic channels “open” can be problematic, since increasing the number of “open” mic channels automatically decreases the gain the sound engineer has available to them before they induce feedback. Muting all mic channels that aren’t used for a particular moment counters that problem but makes it possible for the embarrassing “my mic is muted” moments to occur. Putting an expander on each mic channel and setting it properly can give the engineer the best of both worlds.
10. Use a spectral analyzer while running sound.
This can be helpful with identifying feedback, fine-tuning channel EQ, or finding an annoying frequency. If you have a computer and a 2 channel interface for recording you can do this without an expensive hardware unit. Use the first recording channel to record what you want people to hear later (i.e. the sermon.) Use a mono out, tape out, matrix out, etc. from the board to do this. Use a headphone splitter on the headphone output of your mixing console and send one split to your headphones/monitors (duh) and the other to the computer’s second recording input. Drop a spectrum analyzer plugin on channel 2 in your recording software (BlueCat audio and Voxengo have free ones.) Now, whenever you solo an instrument you can see its signal in the spectrum analyzer.When nothing is solo’d you get a spectral picture of the whole mix from what the board sees. If you want to see a spectrum of the live sound and have a free channel on the board, turn down the fader and aux sends on that channel so it doesn’t get sent anywhere, then hook a room mic up to it. Most solo buttons on mixers are pre-fader levels, so you should still get sound from this room mic going to your board’s headphone output, and therefore to your spectral analyzer.
11. Be aware of your available power.
Many churches weren’t wired for amplified sound. Oftentimes the people that know the actual routing of wires in the building are long gone, but it pays to find out. This will enable you to avoid having electrically noisy lights/dimmers plugged into the same circuits as your audio equipment. Also, if there are multiple sources of power onstage, make sure it’s obvious to the musicians which ones they should use for their instruments. Otherwise your perfect sound could be ruined by a ground hum loop just because the bass player got sloppy and plugged into the wrong circuit. Nothing kills intelligibility like a loud hum or buzz that’s not supposed to be there.
The bottom line is to remember that, regardless of the venue, speaker coverage is as much of an art as it is a science, particularly if you’re working with limited resources. Considering the concepts we’ve outlined can get you close to perfect coverage, but in most cases getting the best possible PA speaker coverage is a matter of putting in the time to position speakers, walk the venue, and use your ears to make critical sound-reinforcement decisions. Cheap is cheap for a reason. You get what you pay for. Not expecting small Churches to have a big budget, but always, always buy the best you can afford, even if it means waiting and saving for something decent. Otherwise it’s false economy and may cost you more in the long run.