Speaker Suspension Operation (Fundamentals explained)


The speaker’s suspension, alongside the voice coil, is fundamental to the operation of a speaker.

Speaker suspensions are an essential part of any speaker comprising two main components, the cone surround and the spider, allowing it to move air and produce sound

In this article, we will explore how speaker suspensions work and why they are so important for producing quality sound covering:

  • What does a speaker suspension do?
  • What are the components of a speaker suspension?
  • How does the speaker suspension impact sound?
  • What is the speaker suspension made of?

What Does A Speaker Suspension Do?

A speaker suspension, which is an assembly containing the speaker spider and surround, provides the mechanical link between the frame of the loudspeaker and its cone.

Typically, the suspension system keeps the cone centred on its axis while allowing it to move freely in response to music signals.

The speaker suspension controls distortion by keeping the cone movement linear within its operating range, thereby ensuring that sound waves are accurately reproduced by the speaker.

Without a quality suspension design and components, performance would suffer significantly.

I have spent many hours designing speaker surrounds and spiders and although they are simple components, they can be complex and tricky when trying to create a design, as they involve lots of excursion and a linear response.

What Are The Components Of A Speaker Suspension?

The main components of a speaker suspension include the speaker spider, which is a rubber or cloth ring that supports the movement of the voice coil; and the surround, which is a flexible foam or fabric ring that supports the cone and helps to keep it centred.

Below is an image of a cross-section of a speaker. You can see how the surround supports the movement of the cone and the spider supports the movement of the voice coil.

This entire subassembly of surround, cone, spider and voice coil moves to produce sound.

What Does A Speaker Surround Do?

A speaker surround is a flexible material, usually made of foam or rubber, that surrounds the cone of a loudspeaker.

The purpose of the surround is to provide support and flexibility for the loudspeaker diaphragm or cone so that it can move freely, allowing sound waves to be produced with full range and clarity.

Speaker surrounds also help absorb any unwanted vibrations coming from the driver itself, which helps reduce distortion in sound reproduction.

What Does A Speaker Spider Do?

The speaker spider is a component of the loudspeaker that helps provide support to the cone and voice coil. It is typically made from a plastic or cloth material.

The speaker spider is attached to the frame of the speaker and keeps the voice coil aligned with the magnetic gap to ensure it can move freely when sound waves are produced. The spider also helps prevent any distortion caused by the cone moving too far from its original resting position.

To learn more about speaker spiders and the fundamental role they play in speaker design, check out this article, which covers the topic in greater detail:

The combination of a speaker surround and spider helps to keep the loudspeaker driver in optimal condition for sound reproduction, allowing for maximum acoustic performance.

Together, they help improve the clarity and accuracy of sound, giving you an enjoyable listening experience.

How Does The Speaker Suspension Impact Sound?

The speaker suspension plays an important role in helping create good sound quality. It controls the movement of the cone, which produces variations in air pressure that cause sound waves to form.

The suspension controls the amount of energy that goes into moving the cone and then controls how quickly it comes back to its resting position, allowing a clearer and more accurate reproduction of sound.

Without a good suspension, the sound would be distorted and lack clarity.

In addition, the spider design helps to keep the voice coil centred in the magnetic gap of the speaker. This ensures that the voice coil remains within its linear working range and does not move too far into the gap, which could cause distortion and damage to the speaker.

Without a good suspension system, speakers would produce distorted sound and lack clarity.

What Is The Speaker Suspension Made Of?

The speaker suspension is usually made of a material such as cloth, rubber, or foam. It is designed to be strong and flexible enough to maintain its shape while also allowing the cone of the speaker to move freely in response to changes in air pressure.

Older designs of the spider comprised metal strips that radiate from the centre of the cone and attach to a flexible perimeter frame. This is where the term “spider” came from, as the component looked like a spider from the top. However, most modern spiders are made from a cloth material which helps keep the voice coil centred in the magnetic gap for improved sound quality.

Final Thoughts

In conclusion, the speaker suspension is an important design consideration for a loudspeaker. The speaker suspension system, which includes the cone surround and spider, helps to control the movement of the cone to produce accurate and clear sound reproduction.

The material used in the suspension system must be strong and flexible enough to maintain its shape while allowing for free movement of the cone.

Additionally, the spider design helps keep the voice coil centred and the surround assists in providing a balanced and stable response throughout the entire frequency spectrum.

With proper care, loudspeakers with quality suspensions can last for decades without losing their performance capabilities.

Happy listening!

Engineer Your Sound

We love all things audio, from speaker design, acoustics to digital signal processing. If it makes noise, we are passionate about it.

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