Kids Ministry and Youth Room AV

A ceiling speaker covers a circle at the listener's ears, and the size of that circle is set by how far the speaker is above the ears, not above the floor. The geometry is simple: coverage diameter equals twice the height above the ear plane, multiplied by the tangent of half the coverage angle.

Ear height is 4 feet seated and 5 feet standing. Using the floor instead of the ear plane is the single most common spacing mistake in church AV, and in a 10 foot room it over-states coverage by 67 percent. In an 8 foot kids room it over-states it by a full 100 percent, which is how a room ends up with half the speakers it needed and dead spots between the tables.

For a typical 90 degree ceiling speaker, a 9 foot ceiling gives only 5 feet of drop to seated ears and therefore a 10 foot coverage circle. A 14 foot ceiling gives a 20 foot circle from the same speaker. This is why a low-ceilinged kids room needs a surprising number of speakers and why the committee should see the number before the quote arrives.

Read across to your ceiling height, then choose a spacing pattern. Edge to edge is the cheapest and leaves gaps at the diagonals, which a small kids room can usually live with. Minimum overlap is the normal choice wherever a teaching voice has to be understood.

These are worked examples for rooms the size churches actually build. The count includes the half-spacing from each wall that centres the grid and stops the perimeter speakers firing into the walls.

Distributed rooms run on a 70 volt line, which lets you put a dozen speakers on a single pair of wires and set each one's level with a transformer tap rather than worrying about impedance. An 8 watt tap is the normal choice for a speech and background room with a hard ceiling. Drop to 4 watts in a nursery where the system is only ever carrying quiet music and a leader's voice.

Size the amplifier from the total tap load with the 80 percent rule applied, which is exactly what the 70 volt system calculator does. Twelve speakers at 8 watts is 96 watts of load, which needs a 150 watt amplifier. Twenty speakers at 8 watts is 160 watts, which needs 200 watts. A Crown CDi 1000 covers either with room to add a second zone later, and the full wiring method is in how to wire a 70 volt system.

On speaker choice, a compact 70 volt ceiling speaker such as the Atlas FAP62T or the JBL Control 24CT is the right class of product. A budget pair at $54.95 exists and will make sound, but tap accuracy and driver consistency are exactly what you are paying for in a distributed system, because twenty speakers that each differ slightly produce a room that is never quite even. The comparison is in ceiling speakers for churches.

Say this plainly to whoever is holding the budget, because it will save the church a rebuild. A distributed ceiling system is the wrong answer for a worship band, in a youth room or anywhere else.

Three reasons, all of them physical. A 4 or 6 inch ceiling driver on an 8 watt tap has no low frequency output worth the name, so the kick drum and bass simply are not there. The system is designed for even quiet coverage rather than level, so it runs out of headroom well below the level a band needs. And the sound arrives from directly overhead, which destroys any sense that the music is coming from the people playing it on the platform.

A youth room with a band needs the same thing a small sanctuary needs: a pair of powered loudspeakers on stands or brackets, aimed at the seating, with a subwoofer if the music has programmed low end. For a 50 by 40 foot youth room with a throw of about 40 feet, reaching 95 dBA with 12 dB of peak headroom from a 96 dB sensitive box calls for roughly 1,871 watts per side, which is squarely in QSC K12.2 or JBL PRX912 territory. Work your own room with the amplifier power calculator.

At the smaller end, a 30 by 24 foot youth room with a 30 foot throw needs about 1,053 watts per side for the same target, which a QSC CP12 or an Electro-Voice ZLX-12P G2 handles. Aiming matters as much as power, and that is covered in how to aim and place church speakers.

Kids and youth rooms almost always run with the lights up, which is the number that decides the projector. Brightness is set by foot-lamberts across the screen area, not by a lumen figure quoted in isolation. A 120 inch diagonal screen is 43 square feet, so at 35 foot-lamberts for normal room lighting it needs about 1,356 lumens, and at 50 foot-lamberts for a bright room with daylight windows it needs about 1,938. Round up to 1,500 and 2,000 ANSI lumens respectively.

That is a far smaller projector than most churches assume, and it means a modest unit such as the Epson Pro EX9270 or the Optoma ZH451 is genuinely sufficient in a room this size. Run your own screen through the projector lumens calculator rather than buying on a headline number, and pair it with a pull-down screen such as the Elite Manual 120 inch at $292.56 if the room is multi-purpose.