Active vs Passive Subwoofer (Difference Explained)

The debate about active vs passive subwoofers is legendary.

For some active subwoofers are best and for some passive woofers make a good fit.

When it comes to enhancing the low-frequency sounds in your home theater system, subwoofers play a crucial role.

Subwoofers are specialized speakers designed specifically to reproduce deep bass and deliver a rich and immersive audio experience.

There are two main types of subwoofers available on the market i.e., active subwoofers and passive subwoofers.

In this article, I will go through the characteristics of each and highlight the key differences between them so that you can decide which one makes a good fit for your overall audio setup.

What is an Active Subwoofer?

Active subwoofer diagram

Active subwoofers, commonly referred to as powered subwoofers, include an amplifier. This means that they have their own power source and do not rely on an external amplifier or receiver to operate.

Active subwoofers are self-contained units that require a power connection to function. They typically have a dedicated power cord that needs to be plugged into an electrical outlet.

In other words, you just need to plug the sub into the power source and audio source to fill your large room with boomy bass.

One of the main advantages of active subwoofers is their convenience.

Since they have a built-in amplifier, they are generally easier to set up and use compared to passive subwoofers.

Pros and Cons of Powered sub

Pros

  • Active Subwoofers are easy to install.
  • Require fewer cables and wiring.
  • Includes built-in amplifier to power the subwoofer, so there is no dependency on the additional receiver.
  • Active subwoofers are typically compact units that can be easily placed in your room.

Cons

  • Non-customizable.
  • Use more wattage, resulting in higher energy bills.
  • Expensive than passive subwoofers
  • May not be compatible with your receiver/amplifier.

Also Read: 2 Ohm vs 4 Ohm subwoofer differences

How to connect and power up the Active Subs?

To connect and power your active subwoofer, follow these simple step-by-step instructions:

Step 1: Identify the subwoofer output or pre-out

The first step is to identify the connectivity options that your subwoofer has.

Start by checking your audio source, amplifier, or receiver for a dedicated subwoofer output or pre-out.

It is usually labeled as “SW Out”, “Subwoofer Out,” or “LFE (low-frequency effects) Out.” This output supplies specific low-frequency signals to the subwoofer.

Step 2: Locate the input on the active subwoofer

Start by looking at the input options on the back of the active subwoofer.

The most common input connection is an RCA input, which uses a cable with RCA connectors. Some active subwoofers may also have other input options such as XLR or speaker wire terminals.

Step 3: Connect the subwoofer cable

Take an appropriate cable (RCA, XLR, or speaker wire) and connect one end to the subwoofer output or pre-out on your audio source or amplifier/receiver and connect the other end of the cable to the corresponding input on the active subwoofer.

Step 4: Power on the active subwoofer

Now plug the power cord of the active subwoofer into an electrical outlet and switch it on.

That being said, your sub may still not turn on if it has a power switch at the back. You may have to turn on the power switch to activate the sub.

Step 5: Set the subwoofer level

The last step is to adjust the subwoofer volume control and set the ideal crossover settings.

This control allows you to match the subwoofer’s output to the rest of your audio system, ensuring a balanced sound.

Depending on your active subwoofer model, you may have additional settings such as crossover frequency, phase adjustment, or low-pass filter.

Read the instruction manual of your active subwoofer to set these parameters according to your preferences and the specifications of your other speakers.

Step 6: Test the subwoofer

Once the woofer is activated, play some audio content that includes low-frequency sounds and check if the subwoofer is producing the desired bass response.

You may have to adjust the subwoofer level and other settings as needed to achieve the desired sound balance.

Also Read: How to pair soundbar with subwoofer?

What is a Passive Subwoofer?

Passive subwoofer diagram

A passive subwoofer is usually smaller and less bulky compared to its active counterpart.

The main difference between passive and active subwoofers lies in the power source.

A passive subwoofer depends on an external amplifier or receiver to supply it with power. It does not have a built-in amplifier, which means it requires an additional component to function properly.

Passive subwoofers are also known as “unpowered” or “non-powered” subwoofers. They are called passive because they need an external power source to reproduce sound. In a home theater setup, the passive subwoofer is typically connected to the receiver or amplifier, which provides the necessary power for the subwoofer to operate.

Also Read: What is Low Pass filter in subwoofer? (Explained)

Pros and Cons of Passive sub

Pros

  • Multiple units can be connected together to enhance sound.
  • One can customize their audio requirements.
  • These units are relatively light when it comes to weight.
  • Ideal for lounges or large rooms.
  • The cost of a unit is less than active subwoofers.
  • Uses less wattage compared to its active counterparts.

Cons

  • It needs proper connectivity for better performance.
  • It is time-consuming to set up a passive subwoofer.
  • The setup requires an external amp or receiver for power.
  • The initial setup of passive subs and speakers can be challenging for beginners.
  • Requires additional wiring, thus increasing the cost.
  • Dependency on the receiver or the need to purchase an additional amplifier

Also Read: Parts of Subwoofers (Explained)

How to connect and power up the passive subwoofer?

To power a passive subwoofer, follow these simple step-by-step instructions:

Step 1: Ensure you have an amplifier or receiver

Make sure you have an amplifier or receiver that is capable of powering the subwoofer.

To get this information, read the instruction manual of your passive subwoofer and the receiver so that you know how much power your passive sub requires.

Step 2: Identify the subwoofer outputs

The next step is to locate the subwoofer outputs on your amplifier or receiver.

In most cases, these outputs are usually labeled as “SW Out”, “Subwoofer Out,” or “LFE (low-frequency effects) Out” and may be color-coded or marked with an icon representing a subwoofer.

Step 3: Connect the subwoofer cable

Now connect your subwoofer to an amplifier, followed by connecting the receiver to the amplifier using an RCA cable.

Step 4: Set the crossover frequency

Once the sub is connected, you will need to set the crossover frequency.

Remember, some amplifiers or receivers have a crossover frequency control that allows you to set the point at which the subwoofer takes over the low-frequency sounds.

If you are having a hard time doing so, it’s best to read the user manual of your amplifier or receiver to adjust this setting according to your preference.

Step 5: Configure the amplifier or receiver settings

Access the settings menu of your amplifier or receiver and ensure that the subwoofer output is enabled.

Adjust any additional settings, such as phase or level, to optimize the subwoofer’s performance.

Step 6: Test the subwoofer

Once everything is configured, the final step is to play audio content that includes low-frequency sounds to test the functionality of the subwoofer.

Make sure the volume level is initially set low to avoid any potential damage and gradually increase it to a comfortable listening level.

Also Read: Subwoofer placement ideas for deep bass

Difference Between Active and Passive Subwoofers (What’s the Difference?)

The main difference between a passive and active subwoofer is that active subwoofers contain a built-in amplifier, while passive subwoofers rely on an external amplifier or receiver for power.

This difference has several implications:

Power Requirements

Active or powered subwoofers have their own power supply, so they require a power connection to operate.

On the other hand, a passive subwoofer needs to be powered by an external amplifier or receiver.

Ease of Setup

Active subwoofers are generally easier to set up and use since they don’t require the use of any extra components.

Passive subwoofers, on the other hand, need to be connected to an external power source and may require additional wiring.

Size and Bulkiness

Passive subwoofers are usually smaller and less bulky compared to active subwoofers, which can make them more suitable for installations where space is limited.

There is a size difference because the amp for passive subs is external, as it needs external source of power to reproduce low-frequency sounds.

Power Output

Active subwoofers often have more power and control over the low-frequency sounds they reproduce, allowing for greater accuracy and depth.

Passive subwoofers, on the other hand, rely on the power output of the external amplifier or receiver.

Power Consumption

Active subwoofers may consume more power since they have their own built-in amplifier.

This can result in higher power bills compared to passive subwoofers, which draw power from the amplifier or receiver.

Also Read: Difference between Woofer and subwoofer

How many subwoofers are ideal?

The size and shape of your room, the subwoofer capacity, and its placement will dictate how many subwoofers are ideal for your house.

If the shape of your house is a little bit odd, you will need to add more subwoofers, as curtains, walls, and wooden cabinets may suppress the sound to a certain extent.

The placement of the speakers or the existing audio setup should also be considered while choosing between passive or active subs.

Also Read: How to build subwoofer box for deep bass?

Which is better? Powered or passive?

When deciding between active and passive subwoofers, consider factors such as ease of setup, available space, power requirements, and desired level of customization.

Active subwoofers are a great choice for users seeking a simple and straightforward solution, while passive subwoofers are suitable for those who prefer flexibility and potential future upgrades.

Ultimately, the main goal is to reproduce low frequency sounds accurately and powerfully, creating an immersive audio experience in your home theater.

Whether you opt for an active or passive subwoofer, both types can significantly enhance the audio quality and provide the bass impact you desire.

The key is to understand the differences between two subwoofer types so you can make an informed decision based on your specific needs and preferences.

Take into account the size of your room, the power requirements of your audio system, and your budget to determine which type of subwoofer will best complement your home theater setup.

Remember, the choice between active and passive subwoofers is not a matter of one being inherently better than the other.

It’s about selecting the option that aligns with your individual preferences, system requirements, and desired audio experience.

With the right subwoofer, you can enjoy deep, rich bass that brings your movies, music, and games to life in your home theater.

Also Read: How to wire subwoofers (with diagram)?

Wrap Up

The choice between an active and passive subwoofer comes down to your specific needs, preferences, and the characteristics of your home theater system.

Active subwoofers provide convenience and simplicity, with everything you need in a single unit.

Passive subwoofers on the other hand offer flexibility, customization options, and potential cost savings if you already have a compatible amplifier.

Frequently Asked Questions

Can I convert the passive subwoofer to an active one?

Yes, it is possible to convert a passive subwoofer to an active subwoofer, however, there are a few factors to consider. Factors such as replacing the crossover circuit, connecting an amplifier, and power supply, and finally testing the subwoofer.

Can a passive subwoofer be used in a home theater setup?

Yes, a passive subwoofer can be used in a home theater setup. However, you will need to ensure that your receiver or amplifier can provide enough power to reproduce the low-frequency sounds in a large room.

Which type of subwoofer is recommended for a large room?

If you have a large room, an active subwoofer with a built-in amplifier is generally recommended. This is because an active subwoofer provides more control over the bass output and can deliver higher power levels compared to a passive subwoofer.

How to determine a passive subwoofer?

To determine if your subwoofer is passive, check for the absence of a power cord and the presence of speaker wire terminals or binding posts on the back panel, indicating the need for an external amplifier or receiver. If you are still unsure, check the product manual of your subwoofer or contact the manufacturer for clarification.

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!