Subwoofer Voice Coil: The Heart of Your Subwoofer

A voice coil is one of the components of a subwoofer and speaker that helps the cone move back and forth to create sound.

It is simply a winding of a wire made of copper that is wrapped around a rigid cylinder often called the former or bobbin.

How many voice coils are used in a subwoofer?

Subwoofers typically use Single Voice Coils known as ‘SVC and Double or Dual Voice Coils is ‘DVC.

There’s nominal to no difference between the subwoofers with single or dual voice coils regarding performance in the same range as their other specifications.

However, dual voice coil systems can be customized, giving you a levy to connect an additional amplifier and subwoofer to your existing sound system.

Main differences between SVC and DVC subwoofers?

The main difference is the number of voice coils used in the two types, in simple words, SVC uses a single voice coil and DVC subwoofers use two.

SVC subwoofers will have a single set of terminals with a negative and a positive point. On the other hand, the DVC will have two sets of terminals with two positive and two negative points.

The two terminals in a DVC or a dual voice coil system give more wiring options. It allows you to connect additional subs and speakers if you would prefer.

Whereas, you won’t be able to customize a system using a single voice coil (SVC) similarly.

DVC subwoofers are more costlier compared to SVC systems.

Moreover, DVC subwoofers can be customized to hit the correct impedance loads.

Although, it may not be the same case in certain configurations but can help you explore more options and make things easier.

Which is better SVC or DVC subwoofer?

The choice of SVC and DVC subwoofer systems completely depends on the users’ requirements.

For example; if you change your preference and want to add a boost to the system in the near future. Apart from this, there’s no difference in terms of performance and power specifications between the two.

Simply put, with a DVC set-up, you can hook up an additional amp or a sub to enhance the music system as required.

What is a voice coil made of?

A voice coil consists of a long wire thread that is further wrapped to the former (a rigid cylinder) also known as the bobbin.

The wires are typically made of copper or copper-clad aluminum and the bobbin is a hard paper or metal foil fold which is rolled like a cylinder.

Finally, an adhesive is applied over the former’s surface before wrapping the first layer of wire.

There is more than one layer of wire added around the bobbin (one above the other) and glue is applied between each layer that surrounds the former.

How is a voice coil made?

Voice coils are typically made using small pieces of machinery and can also be handmade. All you need to do is to use the right material according to the type of sound system.

Additionally, voice coils are made or designed depending on the type and size of applications they are going to be used for in subwoofers, speakers, or tweeters.

Finally, wattage and sizes are other significant factors considered in the making of voice coils for specific systems.

Let us look into the steps to make voice coils along with the required components:

The former or the Bobbin

The former or the bobbin is a cylindrical tube that is made using hard paper for smaller applications, however, Kapton or Nomex papers are used for higher-power loudspeakers.

The paper is first rolled to form the cylindrical shape according to the required diameter and size of the assembly. This is how the base of the voice coil is prepared in the form of a bobbin.

In some applications, a band of paper-like material is wrapped around the bobbin to properly lead out the wires from the bobbin. However, the leads of the wire can also be glued to the bobbin.

Metal Wire

The most common type of wire used to wrap the former (the bobbin) is made of copper, however, aluminum, copper-clad aluminum, silver, and all-aluminum are also used in some applications.

Glue is applied to the bobbin’s surface and the required portion is wrapped with the wires firmly. More than one layer of the wires are wrapped and glue is applied between them.

Finally, the two ends of the wires are left for negative and positive points to connect to a terminal that supplies electrical current to the voice coil.

Process Involved to make a voice coil (Infographics)

Voice coil making process

Do subwoofers have motors?

The mechanism used to move the components in a subwoofer is often referred to as a motor.

How does that work? When you look at the structure of the subwoofer’s components a cone is surrounded by a coil that is capable of moving in limited spaces. As soon as the electrical current goes through the coil it converts it into mechanical energy with the help of the magnetic field around it.

Note – The magnetic field is created by the built-in magnets inside the subwoofer.

The created pressure is similar to the effects produced by a motor which further results in the movement of the coil and the cone in a back-and-forth motion.

To conclude, a motor in a subwoofer refers to its parts that produce movement with a similar mechanism used in some typical motors.

Why is the voice coil called the motor in a subwoofer?

You must have come across the term ‘subwoofer motor’ and it must be quite confusing for many.

So what’s a motor in a subwoofer and speaker? The simple answer is, that the components that produce motion in subwoofers and speakers assemblies together are referred to as the motor.

And, the parts responsible for the motion within subwoofers include the magnet, pole piece, the gap, and the voice coil.

However, the voice coil does the job of converting electrical power into mechanical energy which actually creates the movement within the subwoofer parts.

Hence, the voice coil is often referred to as the motor of the subwoofer and speaker.

Frequently Asked Questions

Can you make a voice coil at home?

With the right specifications of its assembly, you can make a voice coil using the required materials. at home. However, make sure to do it yourself only if you are confident enough, or else you may end up damaging the connected components.

Where can I buy a voice coil for my subwoofer?

You can buy a replacement voice coil online or at the local sound system outlet that deals with their repair work and spare parts. Alternatively, you can also contact the manufacturer of your sound system for more information and to check if they have an authorized service center near you.

Which glue is used in voice coils?

Epoxy adhesives are most commonly used to glue voice coils due to their heat-resisting abilities.

Where is the voice coil attached to a subwoofer?

A voice coil is attached to the apex of the speaker or subwoofer cone and converts the electrical charge into motion.

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!