How to Wire Two 8 OHM Speakers to 4 OHMS?

Hey there, buddy! Today, let’s dive into the fascinating world of audio and learn how to wire two 8-ohm speakers to get a combined impedance of 4 ohms. It might sound a bit technical but fear not, I’ll explain it in a super simple way so you can rock that sound system like a pro!

Understanding Speaker Impedance

Okay, before we get our hands dirty with the wires, let’s talk about speaker impedance. Think of it as the resistance that the speaker offers to the flow of electrical current from the amplifier. Impedance is measured in ohms (symbol: Ω). When you have multiple speakers in a circuit, their impedances add up to create the overall impedance seen by the amplifier.

Series Wiring: Doubling the Impedance

One way to wire two 8-ohm speakers is in series. This means we connect the positive terminal of one speaker to the negative terminal of the other, and the remaining positive and negative terminals become our connection points to the amplifier. Here’s a step-by-step guide:

  1. Take your first 8-ohm speaker (let’s call it Speaker A) and identify its positive (+) and negative (-) terminals.
  2. Now, grab your second 8-ohm speaker (Speaker B) and find its positive and negative terminals as well.
  3. Connect the positive terminal of Speaker A to the negative terminal of Speaker B. These two connected terminals will be our “junction point.”
  4. Finally, connect the positive terminal of Speaker B to the positive terminal of your amplifier, and the negative terminal of Speaker A to the negative terminal of the amplifier.

Now, when you wire two 8-ohm speakers in series, their impedances add up. In our case, 8 ohms (Speaker A) + 8 ohms (Speaker B) = 16 ohms. So, in this setup, you’ll end up with a total impedance of 16 ohms. If your amplifier is designed to handle a 4-ohm load, connecting them in series this way won’t give you the desired result.

Parallel Wiring: Halving the Impedance

Not to worry! We can achieve the 4-ohm target by wiring the speakers in parallel. In parallel wiring, you connect the positive terminals of both speakers together and the negative terminals together. Here’s how:

  1. Disconnect the series wiring setup we did earlier, so you have two separate speakers again.
  2. Now, take the positive terminal of Speaker A and connect it to the positive terminal of Speaker B. These will be our positive junction points.
  3. Next, connect the negative terminal of Speaker A to the negative terminal of Speaker B. These are the negative junction points.
  4. Finally, connect the positive junction point to the positive terminal of your amplifier, and the negative junction point to the negative terminal of the amplifier.

In this parallel wiring configuration, the impedance of the speakers doesn’t add up directly like in series. Instead, it follows a different formula to calculate the total impedance:

Total Impedance (in parallel) = 1 / (1 / Speaker A’s Impedance + 1 / Speaker B’s Impedance)

In our case: Total Impedance = 1 / (1/8 ohms + 1/8 ohms) = 1 / (0.125 + 0.125) = 1 / 0.25 = 4 ohms!

Voila! We did it! By wiring the two 8-ohm speakers in parallel, we’ve successfully achieved a 4-ohm load for our amplifier. Now, your sound system should work like a charm without causing any trouble to your precious amplifier.

Common Misconceptions about Speaker Wiring

Hey, welcome back! Now that we’ve learned how to wire two 8-ohm speakers to get a 4-ohm load, let’s address some common misconceptions and important points you should keep in mind when dealing with speaker wiring.

1. Matching Impedance: The Golden Rule

One of the most critical aspects of speaker wiring is ensuring that the total impedance of the speakers matches the specifications of your amplifier. If you connect speakers with an impedance that’s too low for your amp to handle, it can overheat or even get damaged. On the other hand, if the impedance is too high, your amplifier might not deliver its full power, leading to suboptimal audio performance.

Always check your amplifier’s user manual or specifications to find the recommended speaker impedance range. Stick within that range to keep your sound system happy and healthy.

2. Mixing Different Impedances

Avoid mixing speakers with different impedance ratings in the same circuit. For instance, if you have one 8-ohm speaker and one 4-ohm speaker, don’t wire them together. Their mismatched impedance can lead to uneven power distribution and distort the sound. Stick to using speakers with the same impedance values when wiring in series or parallel.

3. Series-Parallel Wiring for More Speakers

What if you want to add more than two speakers to your setup? You can use a combination of series and parallel wiring to achieve the desired impedance. For example, if you have four 8-ohm speakers and want a 4-ohm load, you can wire two pairs of speakers in series (to get 16 ohms each), and then wire those pairs in parallel. The formula to calculate the total impedance, in this case, would be more complex, but it’s definitely doable!

4. Bi-Wiring and Bi-Amping: Different Concepts

Bi-wiring and bi-amping are terms you might encounter when exploring speaker setups, but they are different concepts from what we’ve discussed so far. Bi-wiring involves using separate wires for the low-frequency and high-frequency drivers in a single speaker, aiming to reduce interference and improve audio quality. Bi-amping, on the other hand, involves using separate amplifiers for different frequency ranges, typically used in high-end audio systems to enhance performance. Neither of these techniques directly influences the overall impedance of the speakers, but they can have their own benefits.

5. Don’t Forget Polarity!

When wiring speakers in series or parallel, it’s crucial to maintain proper polarity throughout the connections. If you accidentally swap the positive and negative terminals, you might end up with an out-of-phase setup. This can lead to reduced bass response and an overall thin sound. Double-check your connections to ensure all speakers are in phase.


Wiring speakers might seem like a daunting task, but with a little understanding of impedance and the right connections, you can set up your sound system like a pro. Remember the golden rule: match the speaker impedance to your amplifier’s specifications. Don’t mix different impedance speakers, and if you want to add more, use a combination of series and parallel wiring.

Whether you’re setting up a home theater, a music studio, or just upgrading your stereo system, getting the wiring right will make a significant difference in the audio quality you experience.

So, go ahead and have fun with your sound system, crank up the volume, and enjoy the music like never before! Happy listening!

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