Speakon Wiring: NL4 and NL2 Pinouts
Speakon wiring follows one convention: a single driver or the low section goes on 1+/1−, and on a four-pole NL4 the second pair, 2+/2−, carries the high section of a bi-amped box or a second channel. Neutrik's own rule is "lower numbers for lower frequencies". Wire every sub to 1+/1− and any standard speaker lead will drive it.
The pins
| Pin | Convention |
|---|---|
| 1+ | Positive: sub, full-range or low section |
| 1− | Negative of the above |
| 2+ | Positive: high section when bi-amped, second channel, or unused |
| 2− | Negative of the above |
An NL2 has 1+ and 1− only; an NL4 has all four. Neutrik states that the NL2 cable connector intermates with a four-pole chassis socket and contacts 1+/1−. The reverse is not guaranteed: some NL2 chassis sockets do not accept a four-pole cable connector. An NL4 socket on the cab is the flexible choice.
Pin numbers are moulded on the insert next to each terminal. Read them; don't go by wire colour or position.
Current and cable at sub power
At the power these drivers take, the numbers are not trivial. For an 8 Ω load, I = √(P / R):
- 1800 W into 8 Ω: 120 V and 15 A RMS.
- 3600 W peak into 8 Ω: 170 V and 21 A.
- Two 8 Ω cabs linked (4 Ω) at 1800 W each: 3600 W total and 30 A on the first lead.
Neutrik rates its current SPX cable connectors at 40 A RMS continuous, and standard chassis sockets at up to 25 A RMS (high-current versions up to 50 A audio). Check the rating of the parts you actually fit, especially on a link socket carrying two cabs.
Cable resistance costs level. Copper at 0.0172 Ω·mm²/m gives these losses over a 20 m run (40 m of conductor out and back), ignoring amp output impedance:
| Conductor | Loop resistance | Loss into 8 Ω | Loss into 4 Ω |
|---|---|---|---|
| 1.5 mm² | 0.46 Ω | 0.5 dB | 0.95 dB |
| 2.5 mm² | 0.28 Ω | 0.3 dB | 0.6 dB |
| 4 mm² | 0.17 Ω | 0.2 dB | 0.4 dB |
The series resistance also lowers damping factor. On long runs to 4 Ω loads, go heavier.
Single-driver sub cab
- Driver + to pin 1+ on the input socket.
- Driver − to pin 1−.
- Leave 2+/2− unconnected unless you are passing them to a link socket.
Use crimped or soldered terminations, not bare twisted ends under a screw, and make sure no stray strand can reach another pin.
Parallel link socket
Wire input and link sockets pin to pin: 1+ to 1+, 1− to 1−, 2+ to 2+, 2− to 2−. The driver sits across 1+/1−. Passing 2+/2− through costs nothing and keeps the cab usable on a two-channel lead.
Every linked cab is in parallel, so the load halves with each identical cab: two 8 Ω cabs present 4 Ω, two 4 Ω cabs present 2 Ω, which many amplifiers will not drive. Check the amp's minimum rated load before linking. The maths is in impedance and wiring and 4 ohm vs 8 ohm.
Two-way cabs
Bi-amped (active crossover): one NL4 lead, low driver on 1+/1−, high driver on 2+/2−, each fed by its own amp channel from a processor such as the XR204.
Passive crossover: 1+/1− to the crossover input; 2+/2− unused or passed to the link.
Label which wiring the cab uses. A bi-amped cab on a single amp channel plays only its low section, and the high driver stays silent. See crossover basics.
Polarity
Positive to positive all the way: amp output, lead, socket pin, driver terminal. A reversed cab moves its cone in while the others move out, and bass cancels wherever their outputs overlap. Driver terminals are marked + or with a red dot. Check every cab before it goes out: see testing a new cabinet and phase and polarity.
Safety
At full power a sub amp puts out well over 100 V, as the figures above show. Never wire or rewire a cab connected to a powered amplifier. Speakon is for speaker-level signals only: never use it for mains, and leave mains wiring to a qualified electrician.
Sources: Neutrik speakON product guide (pin conventions, NL2/NL4 intermating, current ratings) and NL4FX product page, checked October 2026. Cable figures calculated from the resistivity of copper; rounded.
Questions
What is the difference between NL2 and NL4 Speakon?
NL2 has two poles, 1+ and 1−. NL4 has four, 1+, 1−, 2+ and 2−, so one lead can carry two channels. Neutrik's NL2 cable connector fits a four-pole chassis socket and contacts 1+ and 1−.
Which Speakon pins do I use for a subwoofer?
Pins 1+ and 1−. That way the cab works with both NL2 and NL4 leads.
How do I wire two Speakon sockets in parallel?
Pin to pin, 1+ to 1+, 1− to 1−, 2+ to 2+ and 2− to 2−, with the driver across 1+ and 1−. Each linked cab halves the load: two 8 ohm cabs present 4 ohms.
How much current does a Speakon carry on a sub?
1800 W into 8 ohms is 120 V and 15 A RMS. Two linked 8 ohm cabs at that power draw 30 A on the first lead. Neutrik rates its SPX cable connectors at 40 A RMS continuous and standard chassis sockets at up to 25 A RMS.
What happens if a speaker is wired out of phase?
Its cone moves opposite to the others, so bass cancels where the cabs' outputs overlap and the low end goes thin.