VB Temple — Sound Plan

Sound Floor Plan — a working surface, not a finished drawing

This plan ships blank on purpose. Every product sits in a parts bin under the plan; drag each piece to where it actually goes. Whatever the drawio shows is what the handbook shows.

VB Temple sound floor plan with a parts bin of speakers, amps, mixers and mics

Editable twin: Illustrations/Sound/Sound_Floorplan.drawio — open it in drawio, move the pieces, save, then run Update Images.sh and refresh this page.

Anything left in the parts bin is gear without a home. The bin holds 14 pieces — 2 mains, 1 center, 4× EV EVID 4.2 (on hand), 3 amps, 2 mixers, 1 wireless mic and the 12U booth rack. A single greyed piece sits in a second bin: the one speaker still missing from the 8-speaker sketch.

The 4× EVID 4.2 change the picture. Xavier has four ElectroVoice EVID 4.2 on hand (on neither order sheet) destined for the sanctuary — and those are exactly the four satellites the distributed sketch calls for. Counting what is owned or ordered, that sketch is now 7 of 8 covered: 2× QSC mains + 1× JBL 29AV + 4× EVID. It is one speaker short, not five, and costs nothing extra so far.

7 speakers, 6 amp channels. Three Crown XLi2500 give six channels, so at least one pair must share a channel — the EVID fills are the pair to double up. Check the EVID impedance first: two 8-ohm cabinets in parallel present a 4-ohm load, which the XLi2500 must be rated for. If they are 70V-tapped instead they need a 70V amp, which this build does not have.

Amp power vs speaker power — how to check it

Before committing a speaker to an amp channel, run these five steps. The whole point is headroom: an amp with room to spare stays clean, while an amp that runs out of power clips, and clipping is what actually destroys tweeters. Under-powering kills more speakers than over-powering does.

Find the speaker's continuous rating. Not "program", not "peak".
Work out the load the amp will see. One speaker = its own impedance. Identical speakers wired in parallel: load = speaker impedance ÷ number of speakers. Two 8 Ω in parallel = 4 Ω.
Read the amp's power at that impedance — amps make more power into a lower load, so the number changes with what you hang on it.
Divide it up: headroom = (amp watts at that load ÷ speakers on the channel) ÷ speaker continuous watts
Aim for 1.5–2×. Below 1× the amp will clip before the speaker is working hard. Above about 3× is safe but easy to abuse — set the gain so you cannot push past the speaker's rating.

Always use the CONTINUOUS number. Manufacturers quote three figures and they differ by 4×. "Continuous" (also called pink noise, RMS or AES) is the real one; "program" is usually double it and "peak" roughly quadruple. The JBL Control 29AV-1 is advertised as 300 W — but that is program. Its continuous pink-noise rating is 150 W, and 150 is the number you calculate with.

The numbers for this build

Item	Impedance	Continuous power	Note
Crown XLi2500 (×3 = 6 channels)	—	500 W per ch @ 8 Ω 750 W per ch @ 4 Ω	1500 W bridged @ 8 Ω. 4 Ω is its minimum stereo load
QSC AD-S10T (main L/R)	8 Ω	250 W	also has 70V/100V taps + 8 Ω bypass
JBL Control 29AV-1 (center)	8 Ω	150 W	300 W figure is program, not continuous
EV EVID 4.2 (×4, on hand)	8 Ω (6 Ω min)	200 W	the plain 4.2 is 8 Ω; the 4.2T is the 70V version

Worked example — all 7 speakers on the 3 Crowns

Running everything at 8 Ω, with the EVID fills paired two-to-a-channel:

Amp / channel	Drives	Load	Amp gives	Per speaker	Headroom
Amp 1 — A	QSC main L	8 Ω	500 W	500 W	2.0× ✓
Amp 1 — B	QSC main R	8 Ω	500 W	500 W	2.0× ✓
Amp 2 — A	JBL 29AV center	8 Ω	500 W	500 W	3.3× — fine, but set gain carefully
Amp 2 — B	EVID 1 + 2 in parallel	4 Ω	750 W	375 W	1.9× ✓
Amp 3 — A	EVID 3 + 4 in parallel	4 Ω	750 W	375 W	1.9× ✓
Amp 3 — B	spare	—	—	—	free for the 8th speaker

The three amps comfortably cover all seven speakers, and one channel is still free — enough for the eighth speaker if the distributed layout gets built. Every load is 4 Ω or 8 Ω, so nothing goes below the XLi2500's 4 Ω minimum.

Check your EVID model before wiring. This maths assumes the plain EVID 4.2 at 8 Ω. If yours are EVID 4.2T, they are transformer-equipped for a 70V line and the numbers below apply instead.

If you ever go 70V instead

All three speaker models can run on a 70V/100V distributed line. That maths is different and much simpler: set each speaker's transformer tap, add the taps up, and the amp's 70V output must be at least 1.2× that total (20% headroom). A dozen speakers tapped at 25 W = 300 W, so you would want a 70V amp of 360 W or more.

The Crowns cannot do this. The XLi2500 is a low-impedance amp with no 70V output, so going distributed would mean buying different amplifiers. Since the 8 Ω plan above already works with the amps on the sheet, 70V is only worth revisiting if the speaker count grows a long way.

Product photos make the pieces look real

Drop photos into Pictures/Sound/ using the filenames listed in that folder's README.txt, then run python3 "Garys Workshop/make_sound_drawio.py". Each piece turns from a colored box into a circular photo badge, same as the network markers. Until then the boxes work fine.

Regenerating resets the board — but it always backs up first. Running make_sound_drawio.py puts every piece back in the parts bin. Before it does, it copies the current drawio to Garys Workshop/backups/ with a timestamp and prints exactly which placed pieces were reset, so a layout can always be recovered. Update Images.sh never regenerates anything — run that as often as you like.

Reference sketch (not the plan of record)

Illustrations/Sound/Speakers arrangment.png sketches an 8-speaker distributed system — 4× JBL Control 29AV plus 4× EV EVID satellites with a delay matrix. Only 3 speakers are on the order sheet, so treat it as an option to evaluate, not the design. The sketch also labels its matrix outputs SQ-5; the sheet buys the Allen & Heath Qu-5, which is what the parts bin says.

VB Temple — Sound Plan

Sound Floor Plan — a working surface, not a finished drawing

Amp power vs speaker power — how to check it

The numbers for this build

Worked example — all 7 speakers on the 3 Crowns

If you ever go 70V instead

Product photos make the pieces look real

Reference sketch (not the plan of record)

Sound TODO — live copy

TODO — Sound (sanctuary first, fellowship hall later)

0 · Decide the design (blocking everything else)

1 · Booth & rack

2 · Speaker mounting

3 · Cabling

4 · Power-on & tuning

5 · Sign-off