AUDIO / 09
Professional connectors: speakON and XLR
Stage connections must withstand handling and resist accidental unplugging. Two common connectors serve different roles: speakON connects a power amplifier to a passive loudspeaker, while three-pin XLR normally carries microphone or line-level audio.
speakON: power to the speaker
speakON is a connector system and trademark of Neutrik. The inserted plug locks with a twist; release its latch to disconnect. Two-, four- and eight-pole versions exist. Contact count determines the possible number of conductors, not automatically the number of speaker bands. Check mating compatibility for the specific plug and socket models.
More contacts, bi-wiring and bi-amping
A conventional full-range connection often uses 1+ and 1−. Four-pole connectors also have 2+ and 2−, which can carry a second power circuit, for example separately amplified low and high frequencies. Bi-wiring runs separate cable branches from the same amplifier channel to sections of a passive crossover; bi-amping uses separate amplifier channels. Four contacts alone provide neither mode. The speaker and amplifier wiring determines their function. Bridged operation can require a different assignment: never infer it from the + and − labels alone.
XLR: signal between devices
XLR is a connector family made by several manufacturers, including Neutrik. In analogue audio, three-pin XLR commonly carries one balanced audio channel. The receiver evaluates the voltage difference between signal conductors, allowing it to reject interference picked up equally by both. Performance depends on the entire connection, not just the connector. Three pins do not mean left, right and ground. The cable contains two signal conductors and a shield; a latch prevents accidental disconnection.
Cable and signal level
For speakON, use speaker cable sized for cable length, current and connector terminals. Thin microphone cable is not a substitute. XLR may connect a microphone to a mixer, or a mixer line output to an amplifier or powered speaker input. Microphone and line levels differ: select the appropriate input and sensitivity. Never connect an amplifier's power output directly to a microphone or line input. Connector shape alone does not establish signal type; older equipment in particular may use XLR differently.
Reading contacts and phantom power
Read the numbers on the connector insert when wiring. The solder-side view differs from the front view, so do not infer positions from a picture alone. Some microphone inputs also deliver phantom power over XLR, typically 48 V for condenser microphones. This does not power passive speakers; enable it according to the connected device's requirements. Do not confuse speakON with powerCON, a system for electrical power connections.
| Connector / contact | Typical function |
|---|---|
| speakON · 1+ / 1− | First power circuit: + / − |
| speakON · 2+ / 2− (4-pole) | Second circuit, if used by the equipment |
| XLR · pin 1 | Shield / ground |
| XLR · pin 2 | Signal + (hot) |
| XLR · pin 3 | Signal − (cold) |