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Wiring

How to Wire 1 Single 2 ohm Subwoofer

Researched from published physics, alignment relations and manufacturer specifications. Updated .

Quick answer

1 single 2 ohm subwoofer can be wired to 2 ohms. A single voice coil driver has one 2 ohm coil, so the only variable is how the drivers combine with each other.

Wiring impedance is pure Ohm's law and there is nothing subjective about it. Series adds impedance, parallel divides it, and every combination below is simply those two rules applied to 1 driver with one coil each.

Single voice coil drivers are simpler but give you fewer choices, which is the reason most car audio subwoofers ship with dual coils. Check what your amplifier is stable to before you choose, because presenting a load below its rating is the most common way amplifiers die. The wiring impedance calculator covers any combination.

What impedance do 1 single 2 ohm sub give?

Every valid configuration, sorted by the load the amplifier ends up seeing.

Wiring options for 1 single 2 ohm subwoofer
ConfigurationFinal load
single coil2 ohms

Published figure Source: Ohm's law and the series and parallel resistance relations. Nothing here is a judgment call. Series adds, parallel divides, and both rules apply to the coils on a driver and to the drivers in a system in exactly the same way.

Which of these should you actually use?

The one your amplifier is rated for, and no lower. A monoblock rated 1,000 watts at 1 ohm and 600 at 2 ohms is telling you it is stable to 1 ohm; running it at 0.5 ohms is outside the rating whether or not it survives the first song.

Lower impedance draws more current from the amplifier and from the whole electrical system. Going from 2 ohms to 1 ohm roughly doubles the current draw, which changes the wire gauge, the fuse and possibly the alternator. Work out the consequences with the wire gauge calculator and the fuse calculator before committing to a configuration.

There is no sound quality advantage to a lower impedance. What you get is more power from the same amplifier, and more heat and more current draw with it.

What the wire itself needs to be

Speaker wire between the amplifier and the subwoofer carries real current at low impedance. Sixteen gauge is enough for a short run at 2 or 4 ohms; at 1 ohm and any distance, step up to 14 or 12 gauge. Keep both legs of each run the same length, and keep polarity consistent across every driver, because one driver wired backwards cancels a large part of the output of the others.

Terminal cups on prebuilt boxes are often the weakest link in the chain. If the cup will only accept 16 gauge and you are running a low impedance load, wire through the cup's own terminals rather than around them, or replace the cup.

Series and parallel, in one sentence each

Series means the current passes through one coil and then the next, so the impedances add: two 2 ohm coils in series are 4 ohms. Parallel means the current splits between them, so identical loads divide: two 2 ohm coils in parallel are 1 ohm.

In practice, series is positive of the amplifier to positive of coil one, negative of coil one to positive of coil two, and negative of coil two back to the amplifier. Parallel is every positive together to the amplifier positive and every negative together to the amplifier negative. Everything more complicated than that is just those two patterns nested.

Single 2 ohm subwoofers and amplifiers that suit these loads

Frequently asked questions

What ohm load do 1 single 2 ohm subs give?
They can be wired to 2 ohms, depending on how the coils and the drivers are combined. There is no single answer, which is the entire reason dual voice coil drivers exist: the same set of subwoofers can present a load that suits whatever amplifier you already own, without changing the drivers.
Does a SVC 2 subwoofer present 2 ohms?
Yes. A single voice coil driver has one coil at its rated impedance, so a 2 ohm driver presents 2 ohms on its own. That simplicity is also the limitation: with a single coil, the only way to change the load is to add or rewire other drivers.
Is a lower impedance louder?
Only because the amplifier makes more power into it, and only up to the amplifier's rating. Halving the impedance roughly doubles the available power, which is about 3 dB, and 3 dB is a noticeable but modest change. It also roughly doubles the current draw and the heat in the amplifier, so the honest way to read a low impedance rating is as a trade rather than as free output.
What happens if I go below what my amplifier is rated for?
The amplifier draws more current than it was designed for, runs hotter, and its protection circuit may shut it down repeatedly. If protection does not intervene, the output stage can fail. Some amplifiers tolerate a lower load and many do not, and the manufacturer rating is the only figure that tells you which. There is no way to know from the outside which kind you own.
Do all the subwoofers have to be identical?
For a shared amplifier channel, yes in practice. Drivers with different impedances in parallel receive different amounts of power, and drivers with different parameters in a shared enclosure fight each other. Mixing sizes or models in one box is a recipe for one driver reaching its excursion limit long before the others. Use matched drivers, or give each one its own amplifier channel and chamber.

12V safety. A car battery will deliver several hundred amps into a short circuit without any drama at all, which is why the main fuse goes within 18 inches of the battery positive terminal. That fuse protects the wire, not the equipment: the length of cable between the battery and the fuse is unprotected, so a fuse at the amplifier end protects nothing. Disconnect the battery negative before you run power wire, and fit a rubber grommet anywhere a cable passes through sheet metal, because a bare edge will eventually cut through insulation.