Passive vs Active Subwoofers: What are the Major Differences?

Difference Between a Passive and Active Subwoofer: Which is Better?

In Subwoofer by Jonah MatthesLeave a Comment

Setting up your own home theater system is both exciting and overwhelming. After all, there are so many different components to consider. When I first started building my home theater system, I had plenty of questions. This is especially true as I learned more about the importance of a subwoofer to a home theater set up. If you are like me, you probably have no idea that there are different types of subwoofers on the market today. When it comes to a home theater, the two most popular, however, are the passive and active subwoofers.

So what is the difference between a passive and active subwoofer? Passive subwoofers require an additional power source like a receiver or amplifier. Active subwoofers include a built-in amplifier and power source and only need to receive an audio source.

Let us take a look at the major differences between the two subwoofer types and how this may impact your design decision.

What Is A Passive Subwoofer?

Passive Subwoofer Connected to a Receiver

A passive subwoofer is one that requires the use of an external power source, such as an amplifier or receiver.  Passive subwoofers are ideal for large rooms that may need multiple units and are preferred by home theater designers.

Speakers and subwoofers both need to draw power from a source in order to produce sound. For passive subwoofers, selecting an amplifier or receiver that outputs enough to power to properly sustain the deep tones produced by your device is important. You will also need to consider how much power will be necessary for your speakers if you are using it in conjunction with the rest of your home theater sound system.

A passive subwoofer may appear more complex when it comes to connecting all the pieces. This is because, not only do you have the source components, but also the additional amplifier. This means you will need more cabling.

Passive subwoofers are most commonly used by those with custom home theater system installations. In fact, many passive subwoofers are mounted in or on a wall as part of a custom installation. Passive subwoofers themselves are often cheaper than active subwoofers, however, custom installations and a more powerful receiver can bring this cost up.

Passive subwoofers also allow you to link multiple units together for larger or dynamic home theater rooms. This means you can spread the bass throughout the room without creating muddied sound or worrying about uneven distribution.

What is An Active Subwoofer?

Active Subwoofer Connected to the Wall and a Receiver

Active subwoofers, also known as powered subwoofers, include their own power source, such as a built-in amplifier. Active subwoofers are easy to set up and are best used in a single subwoofer configuration. Because of this, placement is more important with active subwoofers.

Active subwoofers are typically configured in a way that optimizes each of the built-in components. Because the built-in amplifier is perfectly matched to the power needs of the speaker, active subwoofers are an all-in-one solution for many home theater owners and designers.

Active subwoofers do not require as many cables as their passive counterpart. This means that set up is typically easier as well. That being said, an active subwoofer requires more power (watts) to work. This may appear negligible for some when they receive their power bill, but it is still worth mentioning here.

Because they include everything you need for optimal bass sound, active subwoofers are typically more expensive than passive models. More importantly, however, when Dolby Digital 5.1 became the standard for DVDs, it established a new norm. With five main channels and a Low-Frequency Effects (LFE) channel, Dolby Digital 5.1 paved the way for a designated bass channel. (This channel continues to exist on DVD, Blu-ray and more!) Active subwoofers tend to capitalize on this designated channel and can provide quality sound from a single unit, instead of having to use multiple ones.

Passive vs Active Subwoofers: Which is Better?

Passive vs Active Subwoofers: Which is Better?

There are pros and cons related to each type of subwoofer. Each of these should be weighed to help you decide which subwoofer is best for your intended use. Sound quality is an obvious factor when searching for the right subwoofer. Regardless of the type of subwoofer, quality depends more on the specific make and model you choose. Aside from sound quality, the six key features are:

  • Receiver/Amplifier: Does the subwoofer require an external amplifier? If so, how strong does it need to be?
  • Power: How many watts does it take to power your subwoofer? Can your receiver/amplifier support this level of power?
  • Connectivity: What types of cables will you need and how many?
  • Expense: What will the subwoofer cost you? Are certain types more expensive than others are? Do not forget to factor in the costs of all required components.
  • Set-Up: How easy will the subwoofer be to set up? Do you simply plug it in and play or is set up more complicated?
  • Design: What features are included with your subwoofer? Can your subwoofer be easily integrated into your décor? Are you looking for a more custom approach?

Let us take a look at how passive and active subwoofers stack up based on these criteria.

Pros and Cons of Passive Subwoofers

As previously stated, passive subwoofers are those that do not include a built-in amplifier. This can affect not only the components you need to power them but several other factors.

Passive Subwoofer Pros:
  • Design: Passive subwoofers allow for a more custom configuration and total control over your home theater set up.
  • Power: These subwoofers require less power (watts) to work, having minimal impact on your power bill.
  • Expense: Passive subwoofers are often cheaper than their active counterparts due to the reduced components included in the unit.
  • Set-Up: Works with almost any receiver/amplifier because there is a subwoofer output on almost all units nowadays.
  • Connectivity: Passive subwoofers are your best option when combining multiple subwoofers for a large home theater set up.
Passive Subwoofer Cons:
  • Expense: Cost may significantly increase with the scale and types of components you need to buy.
  • Set-Up: The cables used to connect a passive subwoofer are supplying both power and the signal, therefore, you will need higher quality cables.
  • Power: Need to consider the full load on any amplifier being used for both your speakers and passive amplifier to ensure proper power will be supplied to each connected component.

Pros and Cons of Active Subwoofers

Active subwoofers come with fewer parts because everything you need is already included inside the box. How does this compare to the passive subwoofer?

Active Subwoofer Pros:

  • Connectivity: Active subwoofers are best used in home theater systems that require only one subwoofer.
  • Set Up: There is no need for special or extensive cabling; this makes set up extremely easy.
  • Design: Most active subwoofers are built to capitalize on LFE channels, optimizing bass frequencies from a single speaker.
  • Amplifier: All required components are built-in, meaning you do not have to research which pieces will provide an active subwoofer with optimal power.
  • Design: Can be placed further away from the receiver because the cables are only providing the audio signals.
  • Design: Often compact, active subwoofers are easily placed where needed to ensure the best sound is achieved.

Active Subwoofer Cons:

  • Expense: Often, active subwoofers are more expensive than a single passive subwoofer.
  • Power: Active subwoofers require more power, which may affect your utility bill if used constantly.
  • Design: Placement becomes increasingly important with active subwoofers because only one should be used with your surround sound system.
  • Compatibility: Requires that your receiver/amplifier has a subwoofer pre-out port.

Wireless Connections for Subwoofers

Wireless connectivity is growing in popularity when it comes to electronics. This includes your subwoofer. At present, wireless connections are only natively available with active subwoofers. For some of the newer models, this feature is built in. However, wireless transmitter/receiver kits are also available for older models with home theater receiver, AV processor, or LFE ports. If you’re interested in using a wireless subwoofer kit, I highly suggest the OSD Audio WSK-100 Wireless Subwoofer Kit (on Amazon).

The Final Verdict

While the choice of a subwoofer is ultimately up to you, active subwoofers are the most popular type used in home theaters today. Easy to use, all-inclusive, and compact – active subwoofers optimize designated bass frequency channels and boost your home theater’s performance.

You will need to pay careful attention to placement, but most owners find their active subwoofer to be the right addition to their home theater. While the initial price may appear steeper than that of a passive speaker, it is important to remember that you won’t need additional power from your receiver or amplifier.

That being said, if you already have a receiver with a built-in amplifier, a passive subwoofer can capitalize on this feature and, therefore, reduce your expenses. Passive subwoofers are favored by designers as they are ideal for flush wall mounts and allow for multiple units to be linked together. As long as your amplifier will support this configuration and provides enough power, a passive subwoofer is a viable option for larger spaces and custom designs.  

Why Use A Subwoofer?

At the end of the day, understanding why a subwoofer is an integral part of a home theater sound system is important.

What Exactly Is A Subwoofer?

A subwoofer, in the most simple terms, is a speaker designed to emit low-frequency sounds, more commonly known as bass. Not all subwoofers provide the same quality sound, so make sure you research the brand and model you are considering before you buy it!

Do I Really Need a Subwoofer? Aren’t My Speakers Good Enough?

Your surround sound speakers provide you with a large arrange of pitches and tones. However, the majority of these speakers do not have the range or capacity to replicate or produce truly deep, rich bass tones. Subwoofers were designed to do precisely that. In doing so, a subwoofer enriches your home cinema experience and helps your speakers deliver the full range of sounds. In fact, subwoofers have become all but required if you ask a home theater design expert.

Does Size Matter?

Subwoofers come in a range of sizes. The traditional subwoofer, which was contained in a large case, maybe too big for some rooms. Newer technology, however, has helped manufacturers to reduce the component sizes, as well as overall dimensions, of many of the subwoofers available today. This makes them more easily concealable and even able to be mounted in a wall or cabinet.

How Many Subwoofers Do I Actually Need For My Home Theater System?

Depending on the size or layout of the room, subwoofer dimensions are not the only thing you have to consider. Large areas or oddly shaped rooms may require more than a single subwoofer. As stated previously, this can directly affect the type of subwoofer you invest in as active models cannot be linked together and may muddy the sound.

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