How does a Subwoofer Work

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Updated November 19, 2022

If you have an excellent speaker system, you should understand how subwoofers work to ensure audio quality. Top-level subwoofers deliver low-frequency sounds for a dedicated home theater system or music room setup. By understanding the parts of a subwoofer, you can troubleshoot issues and maximize sound quality. So, stick around to learn how a subwoofer works, and ensure a great listening experience.

KEY TAKEAWAYS:

  • A subwoofer uses large drivers and moving parts to produce low-frequency sounds like bass notes.
  • As electrical energy enters the subwoofer’s voice coil, the resulting magnetic field interacts with a magnet, creating movement in the subwoofer.
  • As the voice coil reacts to the magnetic field, the movement of the cone disrupts the air to create sound.

Learn how a wireless subwoofer works if your audio receiver uses a wireless connection. That said, you’ll need a wireless transmitter if your theater receiver uses a wired connection. While you’re investigating wireless subwoofers, learn how to play USB drives on Bluetooth speakers.

Insider Tip

You can ensure a deep bass sound from your subwoofer with corner placement, but it may drown out low-powered speakers.

After seeing how subwoofers work, ensure you’ve installed your sound system correctly. Audio connections are usually straightforward, but you should learn how to connect subwoofers to a receiver without a subwoofer output for specialty cases.

Additionally, understanding what a subwoofer does when connected to a soundbar should help you optimize for action movies’ explosions or electronic music’s bass effects. Setting your subwoofer’s crossover region to match the soundbar ensures a proper balance between the regular speakers and the subwoofer.

How Subwoofers Work

In general, there are two types of subwoofers: active and passive. Passive subwoofers need an external amplifier to boost the signal, while active subwoofers use a built-in amplifier. That said, some users apply an additional amplifier to powered subwoofers to further enhance the low-pitched audio signal.

If you want impactful movie sound effects or clear bass notes, understanding the parts of your sound system is a great first step. The subwoofer speaker covers the lowest frequencies from your audio source, leaving the higher frequency range to your other speakers.

Basket

The basket contains all of the necessary components of the subwoofer, and it helps maintain stability for the moving parts. This unit also features vents to keep the hardware cool, and it is ultimately screwed into your subwoofer enclosure.

Surround

This is the foam or rubber piece on the top of the subwoofer. It keeps the cone centered and helps return the voice coil to its original position. The surround helps the subwoofer maintain structure while playing strong bass notes.

Cone

The cone rests at the center of the subwoofer, and it vibrates air to create sound. A cone needs to be lightweight but rigid, so they are usually constructed of plastic or light metal.

Dust Cap

The dust cap prevents dust or dirt particles from touching the cone or other internals.

Spider

The spider is a rigid fabric that connects to the cone and voice coil. This corrugated fabric regulates the upward and downward motion of the cone, and it helps keep the voice coil centered in the magnetic gap. Lastly, the spider prevents dirt and dust from entering the voice coil or magnetic gap.

Tinsel Leads

Tinsel leads link the voice coil to the speaker ports, allowing input signals to reach the voice coil.

Warning

A powerful amplifier can blow out your system if the audio signal exceeds recommended levels.

Voice Coil

The voice coil is a thin wire wrapped around a cylinder, called a former. As electrical energy enters the voice coil, it creates a magnetic field that pushes and pulls against a magnet in the bottom plate. The movement of the voice coil causes the cone to move, creating sound.

STAT: The NIOSH REL (Recommended Exposure Level) for louder sounds over 100 decibels is about 10 minutes to prevent hearing loss. (source)

How does a Subwoofer Work FAQs

Are additional subwoofers worth it?

While too many subwoofers may throw off the balance of music or theater sound, two to three units should result in smoother bass levels. Additionally, you can get a more balanced bass response thanks to the dispersion of sound with multiple subwoofers.

What's the best place for a subwoofer?

Placing your subwoofer in the corner should deliver the most impactful bass frequencies. That said, center placement near the left and right speakers should deliver a balanced bass tone.

How do I clean a subwoofer?

Use a dry microfiber cloth to clean the dust plate and subwoofer surrounds. You can also use a barely-damp cloth to clean dust and dirt from the subwoofer enclosure.