What is a Passive Radiator Subwoofer?

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Updated October 26, 2022

If you are new to the world of diverse stereo setups, you may wonder what is a passive radiator subwoofer. Many of the best speakers, after all, are subwoofers, and passive radiator subwoofers are a popular sub-category. So how many of the best subwoofers are passive radiator versions, what is a passive radiator subwoofer, and what are the pros and cons? Keep reading to find out.


  • Passive radiator subwoofers use a passive driver and not an active driver design, so they do require an external power source.
  • However, these subwoofers lack a bass port, so you can place them just about anywhere without fear of errant sound waves.
  • Radiator designs also allow for a full seal, increasing the durability and lifespan of the subwoofer and the voice coil.

What is a Passive Radiator Subwoofer

As the name suggests, a passive radiator subwoofer is not powered in the traditional sense if you wonder how to get deep bass from a subwoofer without a power source. These speakers feature enclosures that trap sound pressure to create a heavy bass response, which is useful when wondering why your subwoofer is bottoming out.

Insider Tip

No matter which design you choose, make sure it integrates with the components of your pre-existing setup.

In other words, this takes a natural acoustic approach to learning how to make a subwoofer louder. Sound is just vibrations, after all. Passive radiator designs are common across the speaker spectrum, as they are found in many types beyond 8 vs 10 subwoofers.

Benefits of a Passive Radiator Subwoofer

The benefits of using a passive radiator system for bass frequencies are myriad, especially when this tried-and-true technology is applied to subwoofers.

No Need for a Bass Port

The bass port is one of the most confusing aspects of a traditional subwoofer. Remember, the sound is movement, so the bass port jettisons unnecessary air as the subwoofer goes about its tasks. This port makes placement difficult, as placing the speaker close to a wall will impact the sound as the port releases air. Due to the passive nature of the design with passive subwoofers, a bass port is not necessary. In other words, you can place these things just about anywhere.

Sealed Designs

Along with the absence of a bass port, the entire subwoofer can be sealed in the case of a passive design. This gives passive radiator subwoofers increased speed and control, as sealed speakers are generally more precise than those without a proper seal. Also, sealed subwoofers tend to last longer.

STAT: They are called ‘passive’ because they are not powered by electricity; rather, they are powered by the air pressure created by the smaller speaker cones, which receive all of the electrical power from the battery or AC source. (source)


The analog nature of passive subwoofers allows for extreme durability and a longer-than-average lifespan. These speakers take a licking and keep on ticking. This is due to the absence of a bass port, as these ports can build up debris and cracks over time, and the nature of a sealed design. Sealed speakers require less maintenance than other speaker types.

Passive Radiator FAQs

When to buy ported speakers?

Ported speakers offer a high volume, a distinctive resonant frequency, an easily-accessible tuning frequency, and more. The only downside is that you have to watch out where they are placed.

When to buy passive speakers?

Passive speakers offer a true-to-life transient response and tuning frequency, which cannot be said of all active drivers. However, the downside is twofold. The volume tends to be lower than in active speakers, and the bass response might be slightly diminished.

Which subwoofer design should you choose?

This depends on your preferences regarding transient response, resonant frequency, tuning frequency, speaker cone design, bass-reflex design, bass-reflex enclosure, power demands, and more.
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