The Neutrik speakON NL4 (current production model NL4FXX-W-S) is a dedicated 4-pole loudspeaker connector designed for high-current speaker cable assemblies in professional audio applications. It employs a twist-lock mechanism and is rated at 37 A / 250 V AC per IEC 61984 (35 A / 250 V AC per UL1977), with contact resistance of no more than 2 mΩ. The connector is certified to IEC 61984 and accepted as a component under IEC 62368-1; it must not be used for AC mains or power-supply connections. Its four contacts — designated 1+, 1−, 2+, and 2− — allow two independent speaker circuits or bi-amplified wiring within a single connector body.
| Name | Pin | Description |
|---|---|---|
| 1+ | Positive 1 | This pin carries the signal from amp to the speaker |
| 1- | Negative 1 | This pin carries the negative back to the amplifier (of channel one) |
| 2+ | Positive 2 | Second positive from amp |
| 2- | Negative 2 | Second negative back to amplifier from speaker (of channel 2) |
Signals
- 1+ — Positive (hot) conductor of speaker circuit 1; carries the amplified signal from the amplifier output to the loudspeaker.
- 1− — Negative (return) conductor of speaker circuit 1; completes the circuit back to the amplifier.
- 2+ — Positive (hot) conductor of speaker circuit 2; used for a second independent speaker circuit or the high-frequency path in bi-amplified systems.
- 2− — Negative (return) conductor of speaker circuit 2; completes the second circuit back to the amplifier.
Notes
- The NL4FXX-W-S replaces the discontinued NL4FX and NL4FC models and is the current production 4-pole speakON cable connector.
- Accepted cable outer diameter: 6–12 mm; conductor cross-section: 1.5–4 mm² (17–11 AWG).
- The twist-lock mechanism requires a deliberate quarter-turn to engage or disengage, preventing accidental disconnection under load.
- The connector must NOT be used for AC mains wiring or general power-supply connections; it is rated for speaker-level signals only.
- Dielectric strength: 2.8 kVac; insulation resistance: > 10 GΩ.
- In single-circuit (stereo or mono) applications, only the 1+ and 1− contacts are used; the 2+ and 2− contacts remain unconnected unless a second circuit or bi-amp wiring is required.