SpeakON Wiring Reference

Pinout diagrams and wiring conventions for Neutrik SpeakON loudspeaker connectors — NL2, NL4, and NL8. Covers single-channel, bi-amp, stereo, bridged mono, pass-through, and 4-way (multi-way) configurations.

SpeakON Connector — Wiring Side (Rear Terminal View) NL2: 2-pole (1±) · NL4: 4-pole (1±, 2±) quadrant layout · NL8: 8-pole (1± to 4±) staggered inner+outer rings NL2·NL4 latch at top · NL8 keyway adjacent to 1+ Per Neutrik NL2FX / NL4FX / NL8FC NL2 — 2 Pole 1+ 1- 1- = Signal (−) 1+ = Signal (+) NL4 — 4 Pole 1+ 2+ 1- 2- 1- = Ch A / LF (−) 1+ = Ch A / LF (+) 2+ = Ch B / HF (+) 2- = Ch B / HF (−) NL8 — 8 Pole 4- 4+ 1+ 3- 3+ 1- 2+ 2- 1+/1- · 2+/2- · 3+/3- · 4+/4- (Ch A–D)

Connector Comparison

ModelPolesCircuitsMax Wire SizeCurrent RatingTypical Use
NL2 2 1 12 AWG (4 mm²) 40A RMS (37A NL2FXX, 30A older NL2FC) Single full-range, subs
NL4 4 2 12 AWG screw
up to 10 AWG soldered		 30–40A RMS depending on model Stereo, bi-amp, bridged mono
NL8 8 4 12 AWG 30A RMS per contact (40A audio) 4-way (multi-way) systems, large line array cabinets

Current ratings vary between connector generations. NL4FX series handles 40A RMS; older NL4FC is rated for 30A. Always check the connector body for its specific rating. SpeakON connectors are not rated for AC mains power — use PowerCON or true1 for that.

Wiring Configurations

Cable colours vary widely by manufacturer. Professional 4-core cables commonly use Red/Black/White/Green or European colours (Brown/Blue/Black/Grey). There is no universal standard — always verify pin continuity with a multimeter before powering.

ConfigurationAmp SideCableSpeaker SideNotes
Single channel
full-range		 1+ / 1- 2-conductor 1+ / 1- Most common. NL2FC or NL4FC wired to pins 1 only. Works with both 2-pole and 4-pole chassis connectors.
Bi-amp
LF + HF		 Ch A: 1+/1-
Ch B: 2+/2-		 4-conductor LF: 1+/1-
HF: 2+/2-		 Active crossover required in system processor or amplifier. Drive LF on pins 1, HF on pins 2.
Stereo / dual cabinet Ch 1: 1+/1-
Ch 2: 2+/2-		 4-conductor Cab A: 1+/1-
Cab B: 2+/2-		 Single NL4 cable drives two passive cabinets. Both must present the correct impedance load to their respective amp channel.
Bridged mono Amp bridged out:
1+ (+ve), 2+ (−ve)
confirm in amp manual		 4-conductor
(only 2 used)		 1+ (+)
1- (−)		 Requires special bridged-mode cable. A standard 2-wire cable (1+/1-) plugged into a bridged amp will draw signal from channel A only, delivering zero bridged power. Pin assignments vary by manufacturer — always verify in the amplifier manual.
Pass-through / link NL4 in Wired 1:1
all 4 pins		 NL4 out to
next cabinet		 All four pins paralleled. Used in splitter boxes, distribution panels, and cabinet through-ports.
4-way (multi-way) 4 amp channels
A–D		 8-conductor LF: 1+/1-
MF: 2+/2-
HF: 3+/3-
VHF: 4+/4-		 Large line array and processor-driven systems. NL8 at both ends. Each circuit carries one pass-band.

Bridged Mono — Understood

Bridged mono wiring is the most misunderstood SpeakON configuration. A common misconception is that plugging a standard 2-wire cable (wired 1+/1-) into a bridged amplifier will short channel B to ground. In reality, pins 2+ and 2- remain unconnected — the cable simply draws signal from channel A only, delivering zero bridged power at reduced voltage.

To actually get bridged output, the cable must be wired to both 1+ and 2+ at the amplifier end. At the speaker end, 1+ goes to the positive terminal and 2+ connects to the negative (or 1-). Some manufacturers assign this differently — always check the amplifier manual and clearly label any bridged-mode cables.

Assembly Quick Reference

  • Wire strip length: 12 mm for screw terminals (strip outer jacket by 25 mm)
  • Screw torque: 0.8 Nm max with POZIDRIV #1 (0.7 Nm max for Torx T8 on newer FXX series)
  • Cable OD range: 6–15 mm (NL4FC/NL4FX), 8–20 mm (NL8FC)
  • Wiring order (Neutrik tip): Land the upper/less-accessible pair first (2+, 1-), then the lower pair (2-, 1+) — this gives better screwdriver access to the upper terminals. On NL8, screw inner ring contacts first then outer ring.
  • Strain relief: The chuck must clamp the cable jacket, not the individual conductors. Leave 10–15 mm of jacket inside the connector.
  • Polarity test: Always verify with a cable tester or DMM continuity check before connecting to powered equipment. Positive signal on "+" should produce outward cone movement.
  • Boot first: Slide the boot and chuck onto the cable before stripping or soldering. Cannot be added after termination.

Common Pitfalls

ProblemReality
2-wire cable in an NL4 connector If only 1+/1- are landed, the NL4 shell at the other end carries nothing on 2+/2-. You only get one circuit — verify cable is fully wired before expecting 2-channel operation.
Bridged mono cable confusion A standard 1+/1- cable plugged into a bridged amp does not short channel B — it simply gets no bridged power. Bridged operation requires a cable wired to 1+ and 2+ at the amp end.
SpeakON vs mains power SpeakON connectors are NOT rated for AC mains. Neutrik explicitly warns against this. Use PowerCON or true1 connectors for power distribution.
Polarity convention unknown By standard, "+" on the connector should produce outward cone movement (test with 1.5V battery). A few manufacturers reverse pin assignments — always check the speaker's datasheet.
Cable colours assumed universal 4-conductor cable colours vary by brand (Red/Black/White/Green, Brown/Blue/Black/Grey, etc.). Never rely on colour memory — continuity-test every new batch.