Wiring It Up

Watch the two-minute narrated summary first, then work through the lessons and the quiz.

01Connectors: what plugs into what

RCA: CD / controller out — Every plug in this module. Speakon carries speaker level: it only ever goes between an amplifier and a passive box.

TRS jack: line level — Every plug in this module. Speakon carries speaker level: it only ever goes between an amplifier and a passive box.

Every rig in this module uses four cable types. Learn the four and you can read any wiring diagram on site. The colour code below is used in every diagram on this page.

Cable	Looks like	Carries	Balanced?	Rule
RCA (phono)	Red and white pair of push-on plugs	Line level from CD players, DJ controllers, laptops	No. Unbalanced.	Keep it short: under 3 m. Longer picks up hum. Use a DI box for a long run.
XLR	3-pin, latching	Mic level or line level. Mixer outputs to powered speakers or amps.	Yes.	Can run 50 to 100 m without hum. The standard for everything between mixer and speakers.
6.35 mm jack	Guitar-lead plug. TS (two rings) or TRS (three)	TS: unbalanced. TRS: balanced line.	TRS yes, TS no.	A TS jack over 10 m is a hum generator. Prefer XLR for anything between mixer and speaker.
Speakon	Round, twist-lock, 2 or 4 pole	Amplifier output to a passive speaker. High current.	n/a (power)	Only ever amp-to-passive-speaker. Never into a mixer, a powered speaker or a processor.
Mains	3-pin or 16 A Commando	230 V to every powered box	n/a	Powered speakers need two cables: signal (XLR) and power. Forgetting the second one is the number-one "dead speaker" on site.

The one rule
Signal cables carry a whisper. Speaker cables carry a shove. Red RCA and blue XLR never go where a yellow Speakon goes, and the other way round.

02Stereo into powered speakers

DJ controller and small mixer backstage with RCA and XLR cables connected — Controller into the mixer on RCA, mixer out to the speakers on XLR. Keep the spare leads coiled next to the desk, not under it.

The most common rig at a corporate event. One stereo source, one mixer, two powered speakers. Three things to get right: the source is stereo so it needs two cables; the mixer's main output is stereo so it needs two cables; each powered speaker needs signal and power.

In the B&W kit: Evox 8 and Evox 12 columns and the JBL powered subs are all powered boxes. XLR in, XLR link out, power in.

Hover or tap any cable or box to read what it is. Red/white RCA from the CD player or controller into one stereo channel on the mixer. Blue XLR from Main L and Main R out to the left and right speaker. Grey power to each speaker.

What's this?

Hover a cable or a box in the diagram.

CD player / controller → mixer: red and white RCA, unbalanced, under 3 m, into one stereo line channel (or two mono channels panned L and R).
Mixer Main L → left speaker, Main R → right speaker: XLR, balanced, any length up to 100 m.
Each powered speaker: XLR in + 230 V mains. Gain knob on the back at about three-quarters.

Common mistakes on this rig

Only one RCA plugged in: the source is mono on one side, so one speaker is quiet or silent.
Both XLRs out of Main L: both speakers play the left channel. It works, but it's mono, and any stereo pan on the mixer vanishes.
Speaker gain at full with the mixer at −20: hiss. Mixer at unity, speaker at three-quarters (Module 2, Lesson 8).

03Adding a third powered speaker

Rear panel of an RCF Evox 8 showing input and link connectors — The Evox 8 rear panel: input in, link (thru) out. The link is a copy of the input at line level, ready for the next powered box. Photo: RCF.

Every powered speaker has an XLR link (sometimes marked thru or out) next to the input. It is a straight copy of whatever comes in. Plug an XLR from the link of one speaker into the input of the next and you have added a box with no extra mixer outputs. This is the powered-speaker version of "parallel", and because each box has its own amp, there are no ohms to worry about.

The third speaker hangs off the right speaker's link out. It plays the right channel. Put it where you need more right-side coverage, or feed it from a mono output on the mixer if it's a fill at the back.

Try it: link a third box

Third speaker linked from speaker R

Three boxes, two mixer outputs. The link out passes the right channel on.

Link/thru is a copy of the input. You can chain several boxes. Rule of thumb: no more than four on one chain, and check the last box's input is still clean. A fill at the back is better fed from a mono or aux output on the mixer, with its own delay if it's more than 15 m from the mains.

Link out is not a Speakon
The link carries line level, not speaker power. It needs the next box to be a powered speaker. Linking into a passive box does nothing.

04A processor in the chain

When tops and subs are separate boxes, something has to split the signal: bass to the subs, everything else to the tops. That is the processor (also called a crossover, DSP or system controller). It sits between the mixer and the amps or powered boxes. Modern powered subs often have the crossover built in, but a separate processor lets you set it properly and add delay and limiting.

Mixer Main L/R into the processor. Two-way: the processor sends low L/R to the sub amp and high L/R to the top amp. Three-way adds a mid band for a separate mid driver or amp channel.

Try it: two-way or three-way, and where it crosses

Two-way (sub / top) Three-way (sub / mid / high)

Sub to top (or mid): 100 Hz

Setup	Crossover points	Goes where
Two-way	80 to 120 Hz (100 Hz typical)	Below: sub amp or powered sub. Above: top amp or powered top.
Three-way	80 to 100 Hz, then 1.2 to 2 kHz	Sub, mid driver, horn. The second point comes from the speaker's spec sheet.

Use 80 Hz when the tops are 15" boxes that carry some bass. Use 100 to 120 Hz with 10" or 12" tops. The processor also holds the limiter and any delay for fills.

Why bother
Without a crossover the tops try to play bass they can't, and the subs play vocals they shouldn't. Splitting the job makes both boxes louder and cleaner. Module 7 covers how to set the processor up.

05Amp and passive speakers: the ohms

Speakon lead linking a second passive speaker from the first one's parallel socket — Second passive box linked off the first. The amp now sees 4 Ω on that channel.

Old school, and still how line-array elements and many hire rigs run. The mixer feeds a power amplifier. The amp drives passive speakers over Speakon leads. Now the ohms matter, because the amp sees every box you hang on a channel.

In the B&W kit: the D208A line-array elements are passive. They need an amp and Speakon leads, and the ohms matter.

CD player into the DJ mixer. Master L/R out on XLR into the amp's inputs. Amp channel A to the left speaker, channel B to the right, on Speakon. One 8 Ω box per channel.

Try it: add boxes per side

8 Ω speakers on each amp channel

Amp minimum load

8 Ω

load per channel

500 W

amp output per channel (typical 500 W @ 8 Ω amp)

+0 dB

louder than one box

Boxes per channel	Load	Typical amp output	Verdict (4 Ω amp)
1 × 8 Ω	8 Ω	500 W	Safe
2 × 8 Ω linked	4 Ω	~850 W	At the limit, allowed, about +4 dB louder
3 × 8 Ω linked	2.7 Ω	amp protects or fails	Not allowed

Linking passive boxes
Link out on a passive speaker is a parallel connection. Two 8 Ω boxes make 4 Ω. More current, more power, more heat. Stop at the amp's minimum load, printed on its back.

06Soundcheck: find the fault

Ten problems. Each one shows a rig, what you hear, and what the meters show. Click the cable or box you think is at fault. The meters are the clue: signal on a meter means everything before that point is fine.

Problem 1 of 10

Score 0

07Wiring order and the two-minute check

Wire in the same order every time, then test the chain from the source forward before doors. It takes two minutes and it catches nine faults out of ten.

Power first, switched off. Mains to every powered box and the amp. Nothing on yet.
Speaker side. XLR from mixer mains to speakers (or to processor, then amps, then Speakon to passive boxes). Label each lead at the mixer end: "L", "R", "Sub".
Source side. RCA from CD player or controller into the mixer. Red to right, white to left. Check the mixer channel is a stereo line channel, or two channels panned hard L and hard R.
All gains and faders down. Mixer on. Processor on. Speakers or amp on, last.
Play a track you know. Bring up the channel fader to unity. Watch the mixer meters: both L and R moving? Then the processor meters. Then listen at each box in turn.
Walk the room. Stereo image sits in the middle, bass present, no hum. Mute, and the room goes silent (no buzz means no earth loop).

What you hear	Where the signal stops	Look at
Nothing at all, mixer meters dead	Before the mixer	Source playing? RCA in the right channel? Channel gain up?
Nothing at all, mixer meters moving	After the mixer	Main fader, main XLRs, speakers powered and gain up, processor mutes
One side only, mixer meters show both	After the mixer, that side	That side's XLR, that speaker's power, that amp channel
One side only, mixer meter shows one	Before the mixer, that side	That RCA, the channel pan, a mono source
No bass	Sub path	Processor low out, sub amp, sub power, sub polarity
Hum or buzz on one box	That cable run	Unbalanced lead over 5 m, missing earth, different power phase

08Check what you learnt

Ten questions. Pick an answer for each, then press Mark my answers. You need 8 out of 10 to pass this module. You can retry as often as you like.

Ten questions. Circle one answer for each. The answer key is on the last page. Pass mark: 8 out of 10.

Answer key

Photos: product images courtesy of the manufacturers (RCF, Neutrik) and their distributors; scene photographs are AI-generated illustrations and do not show B&W Productions equipment or events.