Subwoofer Speaker Wire: Choosing Gauge Before Anything Else
Speaker wire for a subwoofer is a low frequency, high current job. Gauge matters more than exotic materials, because resistance in the run wastes amplifier damping and can make a passive subwoofer sound soft and slow.
Quick Answer
Use 16 AWG speaker wire for runs up to about 7 m, 14 AWG for runs up to about 15 m, and 12 AWG beyond that or for 4 ohm loads. Choose stranded oxygen free copper rather than copper clad aluminium, and terminate with banana plugs or spade lugs so the strands do not fray at the terminal.
Gauge by Run Length
| Wire gauge | Resistance per metre | Recommended run, 8 ohm | Recommended run, 4 ohm |
|---|---|---|---|
| 18 AWG | About 0.021 ohm | Up to 3 m | Up to 1.5 m |
| 16 AWG | About 0.013 ohm | Up to 7 m | Up to 4 m |
| 14 AWG | About 0.008 ohm | Up to 15 m | Up to 7 m |
| 12 AWG | About 0.005 ohm | Up to 24 m | Up to 12 m |
| 10 AWG | About 0.003 ohm | Long in-wall runs | Long in-wall runs |
Copper, CCA and Plating
Oxygen free copper
Lower resistance per metre and stable over time. The default choice for permanent installs.
Copper clad aluminium
Cheaper and lighter, with roughly 60 percent more resistance than the same gauge in copper. It works for short runs of low power speakers, but it is a poor match for a subwoofer drawing real current.
Connector plating
Gold plating resists corrosion at the terminal, which matters in humid rooms and vehicles. It does not change the sound of the copper itself.
Passive vs Powered Subwoofers
| Subwoofer type | Cable used | Signal level | Typical gauge |
|---|---|---|---|
| Passive subwoofer | Two conductor speaker wire | Speaker level | 16 to 12 AWG |
| Powered subwoofer, line input | Single RCA coaxial cable | Line level | Not applicable |
| High level input on powered sub | Speaker wire from amplifier | Speaker level | 16 to 14 AWG |
| Car audio subwoofer | Heavy gauge speaker wire | Speaker level | 12 to 8 AWG |
Real-World Applications
- Home theater in-wall install: 12 AWG in-wall rated cable to a passive sub in the corner.
- Bookshelf system with a compact passive sub: 16 AWG cable, 2 m run, banana plugs at both ends.
- Home cinema with a powered sub: speaker wire from the amp to the high level input.
- Car audio build: 10 AWG cable, soldered and heat shrunk at the driver terminal.
Wiring Checklist
- Measure the actual run and add 20 percent for routing.
- Select gauge from the table, using the 4 ohm column for low impedance loads.
- Keep both conductors the same length even if the sub is closer on one side.
- Observe polarity: red or striped conductor to positive terminal.
- Terminate with plugs or lugs and check for stray strands before powering up.
Related Guides
If your subwoofer is powered and takes a line level input, read Coaxial cable for subwoofer instead. For balanced mic and line connections, see XLR audio cable. For extending a single port rather than wiring speakers, start with USB cable extension.
FAQ
What gauge speaker wire for a subwoofer?
16 AWG for short runs, 14 AWG for medium runs and 12 AWG for long runs or 4 ohm loads. A subwoofer benefits from heavier gauge more than a midrange speaker does.
Does speaker wire quality affect bass?
Gauge and resistance affect damping and control, which changes how tight the bass sounds. Exotic conductor materials have far less measurable effect.
Can I use a coaxial cable as speaker wire?
Not recommended. Coaxial cable is designed for line level signals at 75 ohm, and its thin centre conductor is a poor match for speaker current.
Does cable length need to match on both channels?
For best results, yes. Different lengths mean different resistance, which can shift level and damping slightly between the two channels.