Loudspeakers and coverage
How to Aim and Place Church Speakers
Quick answer
Aim each main loudspeaker at the back row, not the front. In a 250 seat room 35 feet wide with a 45 foot throw, the pattern that fits is about 42 degrees of horizontal coverage per box, so a 60 by 40 degree box beats the usual 90 by 50 and keeps energy off the side walls.
Almost every church speaker complaint has the same cause, and it is not the speaker. It is aim. A box hung flat, level with the platform, throws its hottest energy into the first six rows and the back wall, which is exactly backwards: the front rows are 12 to 16 feet from the source and need the least help, while the back row is 45 to 90 feet away and needs all of it.
The arithmetic is unforgiving. Moving from 16 feet to 45 feet costs 9.0 dB of level by the inverse square law alone, and moving from 30 feet to 90 feet costs 9.5 dB. If the loudest seat in the building is row three and the quietest is the back row, the operator turns the system up until the back row is comfortable, and the front rows get punished for it. Aiming fixes that before a single equaliser band is touched. Work your own room through the speaker coverage calculator and the SPL loss by distance calculator before you drill anything.
On this page
What horizontal pattern does your room actually need?
Coverage width grows linearly with distance, which means the pattern that is right at the back row is far too wide at the front. A 90 degree box covers 60 feet of width at 30 feet and 124 feet at 62 feet, and a typical 250 seat sanctuary is only 35 feet wide. All of that surplus energy goes into side walls, comes back late, and eats intelligibility.
Read the table by finding your throw distance down the left, then reading across to the narrowest pattern that still covers your seating width. That is the box to buy.
A 90 degree loudspeaker covers 124 feet of width at a 62 foot throw, roughly twice the width of the room it is usually installed in.
| Throw distance | 60 degrees | 90 degrees | 100 degrees | 120 degrees |
|---|---|---|---|---|
| 30 ft | 34.6 ft | 60.0 ft | 71.5 ft | 103.9 ft |
| 40 ft | 46.2 ft | 80.0 ft | 95.3 ft | 138.6 ft |
| 50 ft | 57.7 ft | 100.0 ft | 119.2 ft | 173.2 ft |
| 62 ft | 71.6 ft | 124.0 ft | 147.8 ft | 214.8 ft |
| 70 ft | 80.8 ft | 140.0 ft | 166.8 ft | 242.5 ft |
| 85 ft | 98.1 ft | 170.0 ft | 202.6 ft | 294.4 ft |
Coverage width is 2 times the distance times the tangent of half the horizontal pattern. Manufacturers quote the pattern at the 6 dB down points, usually averaged over 1 kHz to 4 kHz, and almost every box widens below 500 Hz whatever the datasheet says.
The 42 degree surprise
Run the sanctuary geometry for a range of seat counts and something useful falls out. A 100 seat room is about 23 feet wide with a 30 foot throw, a 250 seat room is 35 feet wide with a 45 foot throw, a 500 seat room is 50 feet wide with a 64 foot throw and a 1,000 seat room is 68 feet wide with an 87 foot throw. The horizontal angle needed to span the full seating width from a single central point at the back row is about 42 degrees in every one of them, because rooms scale in proportion.
That is the number the 90 degree default is ignoring. Two boxes splayed left and right, each covering a little more than half the width with an overlap at the centre line, want roughly 50 to 60 degrees of pattern each, not 90. The speaker coverage angle chart lists the common patterns and what each one is for, and a 60 by 40 degree box is the honest answer in more churches than the market suggests.
The exception is a fan-shaped or very wide room, where the seating at the platform end is as wide as the seating at the back. There a wide box or a third centre box is correct, and the sanctuary coverage calculator will tell you which.
How to aim a pair of mains
- Find the aim point. Measure from the loudspeaker position to the last row of seats. In a 250 seat sanctuary that is about 45 feet, in a 500 seat room about 64 feet. This distance is the design throw and every other decision follows from it.
- Put the on-axis point on the back row. Tilt the box down so the centre of its vertical pattern lands on the ears of the back row, roughly 4 feet above the floor for seated listeners. The front rows are then covered by the lower edge of the pattern, which is exactly what you want, because they are already 9 dB louder by distance.
- Set the splay from the room width. Point each box so its inner 6 dB edge crosses the centre line at about two thirds of the way back. For a pair of 60 degree boxes in a 35 foot wide room that is roughly 25 to 30 degrees out from centre each. Too much splay leaves a hole down the middle aisle, too little doubles energy at the centre and starves the outside seats.
- Keep the box off the wall. Hang or pole the box so the horn mouth is clear of the side wall by at least 3 feet. A horn firing along a hard wall picks up a strong early reflection about 2 to 5 milliseconds late, which is heard as comb filtering rather than as an echo, and no equaliser removes it.
- Walk the room and listen to speech. Play a recording of the pastor speaking, not music, and walk from the front row to the back wall and across every aisle. You are listening for the level staying within about 6 dB from front to back and for the words staying crisp. Mark the seats where it fails.
- Fix the holes with fills, not with more level. A hole under a balcony, in a transept or in a cry room is a fill speaker problem. Turning the mains up makes the good seats worse without helping the bad ones. Size the delay for the fill with the delay speaker timing calculator.
How high should the speakers be?
Height sets the vertical angle you can achieve without aiming into the back wall. The working rule is that the bottom of the loudspeaker sits at least 2 feet above the tallest head on the platform, and high enough that the line from the box to the back row clears the heads of the people in front. In a room with a 19 foot ceiling and a 45 foot throw, that usually puts the box 10 to 14 feet above the floor with 8 to 14 degrees of downtilt.
Go higher and you gain even coverage but lose the sense that the sound comes from the person speaking. Go lower and the front rows block the throw. Where a room has a balcony, the main boxes are aimed at the main floor back row and the balcony gets its own boxes or a delay ring, which is covered in under-balcony delay speakers.
On a stand rather than a hang, a tripod puts the horn at about 6 feet, which is below the heads of standing worshippers. That is why a portable system sounds fine in an empty room and muddy with 150 people in it. A taller stand such as Ultimate Support TS-90B Telelock Tripod Speaker Stand Pair is a cheap fix, and a portable rig is planned properly in portable church AV setup.
Where the boxes go relative to the microphones
Placement decides how much gain you get before the system rings. Every main loudspeaker must be forward of every open microphone, meaning closer to the congregation than the pulpit is. A box hung behind the pulpit line, or a wedge pointed up into a lavalier, hands away 6 to 10 dB of gain before feedback that no processor gets back for you.
The practical test: stand at the pulpit and look at the loudspeaker. If you can see the front of the horn, the microphone can hear it. That single check solves more feedback problems than any of the electronics in feedback eliminators, and the whole procedure for ringing out a room is in how to eliminate feedback in a church.
Front fills matter here too. A pair of small boxes such as QSC CP8 8" Compact Powered Loudspeaker across the front of the platform, delayed to the mains and run 6 to 10 dB down, covers the first three rows so the mains can be aimed properly at the back without the first rows complaining.
Passive or powered, and what that changes about placement
Powered boxes such as QSC K12.2 Active 12" Powered 2000 Watt Loudspeaker or Electro-Voice ZLX-12P-G2 12in. 2-Way Powered Loudspeaker with Bluetooth need a mains outlet at the hang point, which is an electrician job and is covered in electrical planning for church AV. Passive boxes need speaker cable of the right gauge back to a rack amplifier such as Crown XLS1502 2-Channel Class D DriveCore Professional Power Amplifier with DSP, Band Pass Filters & Peak Limiters. XLR/RCA Inputs, 525W at 4 Ohm, PureBand Crossover System. Black, and cable loss matters: 14 AWG is fine to about 75 feet into an 8 ohm box, but at 100 feet you want 12 AWG and at 150 feet 10 AWG to stay inside the 5 percent rule. The speaker cable gauge calculator works your run out, and the trade-off is argued in full at powered versus passive speakers.
For coverage purposes the box is the box. What changes is where the heavy, hot, serviceable parts live. If the hang is 22 feet up over a platform, a passive box and a rack amplifier means a ladder comes out once, at install, rather than every time an amplifier module needs a firmware update.
What usually goes wrong
Four failures account for most rooms we are asked about. Boxes hung flat with no downtilt, so the back row is thin and the back wall is loud. Boxes too wide for the room, so the side walls are doing half the mixing. Boxes behind the microphone line, so the system rings before it reaches a useful level. And a subwoofer placed in a corner because that was where there was space, which adds 6 dB of uneven low end and makes the room boom on two notes.
Fix aim first, then pattern, then position, then processing. Tuning a badly aimed system with an equaliser is how churches end up with a graphic equaliser that looks like a mountain range and a system that still sounds wrong. The order of operations is set out in how to tune a church sound system.
Sources
- Inverse square law and coverage geometry as implemented in the site engine, src/lib/avmath.mjs
- Loudspeaker horizontal and vertical pattern conventions from manufacturer application guides
Frequently asked questions
How far apart should the left and right speakers be?
Far enough to cover the seating width and no further. In a 35 foot wide room that is usually 20 to 26 feet apart, splayed outward. Pushing them to the walls creates a hole down the centre aisle and makes the stereo image irrelevant anyway, because a congregation sits across 35 feet and only the people on the centre line hear both boxes equally. Mono is the correct choice for speech in almost every sanctuary.
Should church speakers be mono or stereo?
Mono, in nearly every case. Stereo only works for listeners sitting roughly equidistant from both boxes, which describes perhaps a tenth of a congregation. The rest hear whichever box is closer, so anything panned hard vanishes for half the room. Run the mains in mono, keep effects and keyboard stereo images inside the mix rather than across the room, and save the stereo pair for the livestream feed.
How much downtilt does a hung loudspeaker need?
Enough that the centre of the vertical pattern lands on the ears of the back row, which is typically 8 to 14 degrees for a box hung 10 to 14 feet up in a room with a 45 to 64 foot throw. Measure rather than guess: the tilt is the angle whose tangent is the height difference divided by the horizontal distance. Most rigging brackets have a printed scale, and a phone inclinometer is accurate enough.
Can I just use more speakers instead of aiming carefully?
No. Extra boxes covering the same seats add level and add arrival-time differences, which smears speech rather than clarifying it. Two well aimed boxes plus a pair of delayed front fills beat four boxes scattered around the platform every time. Add speakers only where a seat cannot see a main box at all, such as under a balcony, in a transept or in an overflow room.
Does the loudspeaker need to be above the congregation?
It needs a clear line of sight to every seat it is meant to cover. High frequencies above about 2 kHz are blocked by a row of heads, and those frequencies carry the consonants. A box at 6 feet on a tripod is behind the heads of standing worshippers, which is why portable systems get muddy once the room fills. Get the horn above head height, and higher if the room is deep.
How do I know if my current speakers are aimed wrong?
Walk the room during a service with a sound level meter app and note the average level at the front row, the middle and the back row. A well aimed system stays inside about 6 dB across those three points. If the front row is 12 dB louder than the back, the boxes are flat or aimed short, and re-aiming costs nothing but a ladder and an afternoon.
Researched, not professional advice. This page is compiled from published manufacturer specifications, operator manuals, FCC rules, published standards and owner-review consensus, not hands-on testing. Sound system design, rigging loudspeakers overhead, and any electrical work are jobs for a qualified professional: have flown loudspeakers and their attachment points signed off by a structural engineer or a certified rigger, and have all wiring done by a licensed electrician to your local code. Wireless microphone rules change, so confirm the current FCC position before buying. As an Amazon Associate we earn from qualifying purchases.