2 ohm vs 4 ohm subwoofers: Ohm difference explained

Choosing the right subwoofer for your audio system can make all the difference in your sound experience.

When it comes to subwoofers, the debate between 2 ohm and 4 ohm options is a common one.

In today’s blog post, we’ll explore the key differences between these two and help you determine which one is best suited for your needs.

What is Ohms in Subwoofer? (Impedance explained)

Ohms (Ω) is simply the unit to measure the electrical resistance. When it comes to subwoofers, it refers to the resistance that the subwoofer presents to electrical audio signals sent from an amplifier. This resistance is also commonly known as impedance which is an important factor to consider when connecting the sub to an amplifier or receiver.

Subwoofers typically have a specified impedance rating, such as 2 ohms, 4 ohms or 8 ohms, and so on.

This rating indicates the electrical load the subwoofer presents to the amplifier. The lower the impedance, the more current the subwoofer will draw from the amplifier.

In other words, the lesser the impedance the easier it is for the current or signal to flow due to low resistance, therefore making such types of subwoofer louder.

Importance of speaker impedance

It is important to match the speaker impedance with the amplifier’s specifications to ensure compatibility and optimal performance.

Incorrect impedance matching can lead to issues such as overheating, damage to the amplifier, lower volume levels, distorted sound, and compromised overall audio quality.

See, if you mismatch the impedance, it may cause damage to your amp and possibly even your subs and that’s not cool.

So, knowing the impedance of your speakers is essential when it comes to wiring them up properly.

For this very reason, it’s recommended to read the labels on both your speakers and your amp to ensure that they’re compatible.

In this table, the impedance options are indicated with either parallel (P) or series (S) wiring.

Subwoofer ConfigurationImpedance Options
1 SVC 2-ohm sub2 ohms (P)
1 SVC 4-ohm sub4 ohms (P)
1 DVC 2-ohm sub1 ohm (P) or 4 ohms (S)
1 DVC 4-ohm sub2 ohms (P) or 8 ohms (S)
2 SVC 2-ohm subs1 ohm (P) or 4 ohms (S)
2 SVC 4-ohm subs2 ohms (P) or 8 ohms (S)
2 DVC 2-ohm subs1/2 ohm (P), 2 ohms (S), or 8 ohms (S)
2 DVC 4-ohm subs1 ohm (P), 4 ohms (S), or 16 ohms (S)
  • Parallel wiring combines the voice coils in a subwoofer configuration, resulting in a lower overall impedance.
  • Series wiring connects the voice coils in a daisy-chain manner, leading to a higher overall impedance.
  • The common subwoofer impedance is usually around 2 or 4 ohms.

2 Ohm Subwoofers

A 2 ohm subwoofer has a lower impedance compared to a 4 ohm subwoofer.

This lower impedance allows it to draw more power from the amp, resulting in louder sound output.

2 ohm subwoofers are generally more power-hungry and require amplifiers that can handle lower impedance loads.

While 2 ohm subwoofers offer increased power and volume, they can be less efficient compared to their 4 ohm counterparts.

This means they may require more power to achieve the same sound level as a 4 ohm subwoofer.

Additionally, running a 2 ohm subwoofer at high volumes for extended periods can put more stress on the amplifier, potentially leading to overheating or distortion.

Here are the pros and cons of 2 ohm subwoofer to understand better:

Pros and cons of 2 Ohm sub

Pros

  • Higher Power Output
  • More Suitable for High-Power Systems

Cons

  • Higher Power Requirements
  • Less Efficient
  • Potential for Overheating or Distortion
  • Possible issues if connected with 4Ω amp

4 Ohm Subwoofers

On the other hand, 4 ohm speakers have a higher impedance and draw less power from the amplifier.

They are generally more compatible with a wider range of amplifiers and offer greater flexibility when it comes to system design.

Due to higher impedance, a 4 ohm subwoofer is more efficient than a 2 ohm speaker.

4 ohm subwoofers are a popular choice for those seeking a balance between power requirements and compatibility.

They provide a wider range of amplifier options and are generally considered more stable when it comes to prolonged high-volume usage.

Pros and cons of 4 Ohm sub

Pros

  • Greater Compatibility (compatible with a wider range of amplifiers)
  • Efficient than a 2Ω sub.
  • 4Ω subwoofers are generally considered more stable when it comes to prolonged high-volume usage.

Cons

  • Lower Potential Power Output
  • Limited Power Compatibility

2 Ohm vs 4 Ohm: Which is Louder?

One common question that arises when comparing 2 ohm and 4 ohm subwoofers is which one is louder.

While 2 ohm subwoofers have the potential for higher power output, it doesn’t necessarily mean they are always louder than 4 ohm subwoofers.

The overall loudness depends on various factors, including the subwoofer’s efficiency, the power of the amplifier, and the design of the audio system.

That being said since 2 Ohm load does not have as much resistance as 4 Ohm counterparts, it allows them to be louder.

Also Read: Woofer VS Subwoofer: Difference between woofer and subwoofer explained

Similarities in 2 ohm subwoofer and 4 ohm subwoofer

  • Both 2-ohm and 4-ohm subwoofers are designed to reproduce low-frequency sounds, particularly bass frequencies, and share similar build quality.
  • The installation process is generally the same, involving connection to an amplifier using speaker wires.
  • Both subwoofers can produce deep, low-frequency bass, although the actual sound quality and performance depend on various factors.
  • The physical construction and overall quality of 2-ohm and 4-ohm subwoofers do not demand any design changes.
  • Both dual voice coil subwoofers (DVC Subwoofer) and SVC subwoofers come in 2 and 4 ohms setups.
  • Two subwoofers or multiple subwoofers can be connected in both cases.

Key differences between a 2 ohm and 4 ohm subwoofer

Difference2-ohm Subwoofer4-ohm Subwoofer
Impedance RatingLower impedance (2 ohms)Higher impedance (4 ohms)
Power HandlingCan handle more powerMay handle less power
Amplifier CompatibilityMay require a specific amplifierMay have broader amplifier compatibility
Wiring ConfigurationsSpecific wiring configurationsSpecific wiring configurations
System EfficiencyPotential for higher efficiencyPotential for lower efficiency
Heat DissipationMay generate more heatMay generate less heat
LoudnessCan potentially produce louder and more powerful bassMay have slightly lower bass output compared to a 2-ohm subwoofer but the quality of sound may be better
DurabilityMaybe less durable as it takes in more currentMaybe more durable than 2 ohm variant
Price and AvailabilityPrice and availability may varyPrice and availability may vary

2 ohm vs 4 ohm amp power diagram (Comparision)

2 ohm vs 4 ohm subwoofer amp power diagram

Also Read: Active vs Passive Subwoofer (Difference Explained)

Differentiating 2-ohm and 4-ohm subwoofers

There are various ways to differentiate 4 ohm and 2 ohm subwoofers, here’s how you can recognize the difference.

Manufacturer Specifications

Check the product documentation or specifications provided by the manufacturer. In most cases, they will mention the impedance rating of the subwoofer, either as 2 ohms or 4 ohms.

Check the manufacturer’s website, packaging, and user manual to find out the impedance of your sub.

Labeling or Markings

Look for any labeling or markings on the subwoofer itself.

A lot of manufacturers have the practice of engraving the impedance rating directly on the subwoofer’s cone, back plate, or on a label attached to the subwoofer.

Product Model

The product name or model number often includes information about the impedance rating in the official manufacturer’s site.

Online sources, forums, or the manufacturer’s website can also provide this information.

Retailer or Manufacturer Support

Contact the retailer or manufacturer directly for assistance as they may already know the accurate information about the impedance rating of the subwoofer.

Trust your ears

The last option is to trust your ears i.e., the 2 ohm variant will be more louder than a 4 ohm variant.

So, listen to both the subs if you are comparing, and if you feel that one sounds clearer than the other and is less loud, it means that the 4 ohms sub is in action.

Importance of matching amplifier Impedance

To ensure optimal performance and avoid potential damage to your amplifier and subwoofers, it’s crucial to match the impedance of the subwoofers with the amplifier’s specifications.

Many amplifiers are designed to work within a specific impedance range, such as 4-ohm or 2-ohm loads.

Using a subwoofer with an impedance outside the recommended range can lead to inefficiencies, reduced power output, and even equipment failure.

Also Read: Pairing Soundbar and subwoofer: Add a Subwoofer for bass

How wiring can affect the sound output of your sub?

Proper wiring not only helps to get the right output but also keeps your speakers and amplifiers safe.

When it comes to subwoofer wiring, you have two different wiring options i.e., wiring in series or wiring in parallel.

If you choose to wire your sub in series, it means you’re connecting the positive terminal of one voice coil to the negative terminal of the other.

On the other hand, parallel wiring means you’re connecting the positive terminals together and the negative terminals together.

This can be a bit tricky, especially if you have a dual voice coil subwoofer.

But if you do it right, you’ll end up with a total impedance that matches the subwoofer’s impedance, which is usually around 2 or 4 ohms.

Be it home or car audio, it’s important to understand how the wiring affects the sound quality.

Whether you choose parallel or series wiring, make sure you have an amplifier that can handle the impedance, and don’t forget to double-check the ohms rating of the amplifier and speaker.

Also Read: How to build a subwoofer box for deep bass? (Guide)

Wiring Configurations: Series vs Parallel

In series wiring, the subwoofers are connected one after another, while in parallel wiring, they are connected side by side.

Wiring subwoofers in series add their individual impedances together. For example, two 4 ohm subwoofers wired in series would result in a total impedance of 8 ohms.

On the other hand, wiring subwoofers in parallel divides the impedance by the number of subwoofers. In our example, two 4-ohm subwoofers wired in parallel would result in a total impedance of 2 ohms.

I covered a detailed article on subwoofer wiring here.

Here’s a quick diagram that explains the difference between series wiring and Parallel wiring.

Parallel and series wiring diagram

Power sharing in subwoofers in series or parallel diagram

Dual Voice coil wiring diagram

Wire a dual voice coil subwoofer diagram (parallel and series)

Can 2 ohm subs be used in a car instead of 4 ohms?

Technically, you can use 2-ohm and 4-ohm subwoofers together in a car audio system. However, you’ll need to ensure that your amplifier can handle a mixed load of 2-ohm and 4-ohm subwoofers.

Also, you’ll need to adjust the wiring configuration to achieve a compatible overall impedance.

Adjustments to the amplifier’s settings are the key to making your subs work as expected.

Lastly, it’s equally important to design the system carefully and choose subwoofers with similar characteristics for optimal integration.

Also Read: Subwoofer Placement Ideas for deep bass (Find the best spot)

Wrap Up

I hope you now know the difference between a 2 ohm and 4 ohm speaker or a sub.

With the right knowledge, you can not only connect a single sub but multiple subwoofers can be connected.

Here are the key points to remember when comparing 2 ohm and 4 ohm subwoofers:

  • 2 ohm subwoofers offer the potential for higher power output and louder sound but can be less efficient.
  • 4 ohm subwoofers are generally more compatible, offer flexibility, and can be more efficient.
  • The overall loudness depends on multiple factors, including the subwoofer’s efficiency, amplifier power, and system design.
  • Wiring configurations such as series and parallel impact impedance and power distribution.
  • When using multiple subwoofers, impedance combines differently depending on the wiring configuration.
  • Matching the subwoofer impedance with the amplifier’s specifications is crucial for optimal performance.
  • Sound quality considerations should not be overlooked, with higher impedance subwoofers often providing better control and bass response.

Frequently Asked Questions

What is the best ohm for subwoofer?

The best ohm for subwoofer depends on your requirement i.e., if your priority is to get louder bass go for a 2-ohm subwoofer, and if your priority is energy efficiency along with clear and low distortion bass go for the 4 ohm.

Is lower ohm more powerful?

Lower Ohm allows the electrical signal to flow with less resistance allowing the subs to be louder.

Do ohms affect sound quality?

Yes, impedance of 4-ohm subwoofers is different as compared to the 2-ohm subwoofer. The difference can be identified through the output i.e., 2 ohm subs will sound louder and a 4 ohm sub will be more balanced and less distorted.

Armed with a Diploma in electrical engineering and a remarkable 12 years of expertise, he excels in rejuvenating music systems, washing machines, dryers, and laundry-related appliances. Manish's profound insights and practical know-how establish him as a credible authority in appliance and music system repairs. Contact: manish.singh (at) subwooferblog.com. He's always ready to lend a helping hand!