Series vs Parallel Subwoofer Wiring: How to Pick the Right One

Series vs parallel subwoofer wiring comes down to one thing: the final impedance your amp sees.

Series vs Parallel Subwoofer Wiring in Plain English

Impedance is measured in ohms, and it’s basically how hard a speaker pushes back against your amp. Lower impedance lets the amp push more power, up to the amp’s limit. Higher impedance means less power and a cooler-running amp.

When you wire in series, the impedances add up. When you wire in parallel, the final number drops. That’s the whole idea. You can read the physics in this overview of series and parallel circuits.

How Series Wiring Works

In series, you connect the positive of the amp to the first coil, then the negative of that coil to the positive of the next, and so on. The last negative goes back to the amp. The impedances add together.

Two 4 ohm coils wired in series give you 8 ohms. It’s a safe choice, but you’ll get less power out of the amp.

How Parallel Wiring Works

In parallel, every positive connects together and every negative connects together. The final impedance drops. Two 4 ohm coils in parallel give you 2 ohms.

That lower number lets a stable amp put out more power. It also means your amp has to be rated for that load. If it isn’t, it can overheat or shut down.

Series vs Parallel Subwoofer Wiring Examples

Setup	Series	Parallel
One dual 4 ohm sub	8 ohms	2 ohms
One dual 2 ohm sub	4 ohms	1 ohm
Two single 4 ohm subs	8 ohms	2 ohms
Two single 2 ohm subs	4 ohms	1 ohm

Which One Should You Choose?

Start with your amp. Check the label or manual for the lowest impedance it’s rated to run. Then pick the wiring that lands on or just above that number.

If your amp is stable down to 2 ohms and your subs wire to 2 ohms, parallel gets you the most power. If your amp only likes 4 ohms or higher, series is the way. Matching the sub’s power rating to the amp matters just as much. Our post on car audio sound deadening is worth a read once your bass is wired up and you start hearing rattles.

Series vs Parallel Subwoofer Wiring Mistakes

The most common one is guessing. People wire to 1 ohm without checking whether the amp is 1 ohm stable, and then wonder why it keeps going into protect.

The next is mixing coil values. Don’t wire a 2 ohm sub and a 4 ohm sub together on the same channel. Also, loose or messy connections add resistance, so use clean crimps or solid terminals.

Series vs Parallel Subwoofer Wiring FAQ

Is series or parallel better for subwoofers?

Neither is better in general. Parallel gives a lower impedance and more power if the amp supports it. Series gives a higher impedance and a safer load.

Does wiring change how loud my sub is?

Indirectly. Wiring changes the impedance, which changes how much power the amp delivers. More power usually means louder, as long as the sub can handle it.

Can I wire two subs with different impedances?

You shouldn’t. Use matching subs on the same channel so each one gets equal power.

How do I check my final impedance?

Use a multimeter before connecting the amp. The reading will be a little lower than the rated number, which is normal.

Get the Right Gear

If you want help matching a sub and amp so the wiring just works, browse dv8shop.com or message us with your setup.