Electric Coils banner

Voice Coil

A reliable source for Voice Coil information and leading Voice Coil Companies & Manufacturers.

A voice coil is a wire coil attached to the top of a speaker cone. It consists of a former winding and a collar. Read More…

Voice Coils A voice coil is a wire coil attached to the top of a speaker cone. It consists of a former winding and a collar.
Request for Quote

Leading Manufacturers

Sag Harbor, NY  |  800-724-5952

We are proud of the craftsmanship of our engineers. All of our products are made right here in the United States and we promise that these items are created from high quality resources. Our electrical coils are unique and efficient.

Request A Quote

Sag Harbor Industries, Inc. $$$

Bristol, CT  |  800-825-4319

Established in 1973, Classic Coil Company is a Contract Manufacturer of electronic coils. We manufacture coils for a variety of industries; winding wire gauges from 4-58 AWG. We are ISO 9001-2015 certified, ITAR registered and DFARS Compliant. Our Engineering services allow us to assist with design, reduce cost, and increase efficiency in production. Call or visit our website to learn more about our capabilities.

Request A Quote

Classic Coil Company $$$

Bristol, CT  |  860-584-0927

We are an ISO 9001:2015 certified company which is internationally known for manufacturing high quality electromagnetic-coils. It is our goal to provide quality products, a commitment to speedy delivery, and competitive pricing. We understand that every application is unique, so we encourage you to contact us to discuss your specific requirements. Call us at 1-860-584-0927 and find out what our 50+ years of experience can do for you.

Request A Quote

Quality Coils, Inc. $$$

Alpha, NJ  |  800-867-3526

Since 1962, Torelco has been a supplier of electric coils and transformers of superior quality. We offer custom coils, solenoid coils, ferrite core coils & toroid wound coils to serve a range of industries. Markets served include medical, military, electronics, and industrial. When you work with us, our promise is to build to the exact specifications and meet the custom needs of our customers.

Request A Quote

Torelco LLC $$$

North Fort Myers, FL  |  239-997-3860

Check out what’s new online at Precision Econowind, manufacturer of the highest quality custom coils at reasonable prices, with on time delivery. Serving the coil industry for over 30 years, we’re experienced with producing loudspeaker & medical industry coils, coils wound on customers’ bobbins/tooling; freestanding, flat wire, edge wound, square, rectangle & shaped coils. Submit your specs today!

Request A Quote

Precision Econowind, Inc. $$$

Perris, CA  |  951-277-0757

Triad Magnetics has been in the electric coils industry for over 75 years. Giving us the knowledge and expertise to be one of the best in the industry. We have a wide range of electric coils and inductors as well as the ability to custom engineer and manufacture electric coils to our customer’s needs. Having served the needs of many industries for more than half a century, Triad believes its experience makes the difference.

Request A Quote

Triad Magnetics $$$

Antigo, WI  |  800-826-9741

Johnson Electric Coil Company is a family owned manufacturer that specializes in custom transformers, coils and inductors. From three phase isolation transformers to single phase inductors and chokes, we carefully design our products to meet your exact specifications.

Request A Quote

Johnson Electric Coil Company $$$
placeholder image Sag Harbor Industries, Inc. Classic Coil Company Quality Coils, Inc. Torelco LLC Precision Econowind, Inc. Triad Magnetics Johnson Electric Coil Company

What Is a Voice Coil?

A voice coil is a wire coil attached to the top of a speaker cone. It consists of a former winding and a collar.

The coil provides a motive force onto the cone due to the magnetic field created by the current passing through it.

Voice Coils

This term is also adopted for linear motor voice coils. An example is those motors used to move the heads within hard disk drives that produce a larger force and move a longer displacement despite working on the same principle.

How Voice Coils Work

In order to function, the speaker system requires a current running through the voice coil, which then creates a magnetic field. Within this magnetic field, the coil attracts a permanent magnet attached to the loudspeaker cone.

Resulting from this attraction, the magnet moves and thus brings the cone together with its audio waveform. As the audio waveform is applied to the coil, the cone produces sound waves identical to the original input signal.

Voice Coil Operation

Types of Voice Coils

There are two categories of voice coils: overhung voice coils and underhung voice coils.

Overhung Voice Coils

Overhung voice coils are generally taller than the magnetic gap. As a result, these coils have a higher mass and significantly low-to-medium sensitivity. Whenever the coil exceeds its limits, it shows a soft nonlinearity.

Overhung Coil Design

Nonlinearity occurs when the output signal strength remains the same despite the changing signal strength. If the nonlinearity is too much, the quality of the loudspeaker is drastically compromised.

Underhung Voice Coils

Underhung voice coils are generally shorter than the magnetic gap. Due to their low coil mass, they exhibit medium-to-high sensitivity. This sensitivity is why underhung speakers are usually installed in high-end speakers.

Unlike the overhung coils, they show a hard nonlinearity when limits are exceeded.

Underhung Coil Design

Applications of Voice Coils

The medical industry is a leading example regarding the adoption of voice coil actuators. Medical equipment and devices have gone through a notable reduction in size and mass over the past years so that they can be as portable as ever.

This progression in reducing the overall weight and size demanded that each part be as small and lightweight as possible. The voice coil actuators are suitable for this trend and are considered reliable, highly efficient, and precise.

Typical examples of medical devices that use voice coils are ventilators and pumps for dosing and metering of patients.

Voice Coils in Ventilators

Many industries use optics, devices that detect or manipulate light; typical examples are mirrors, microscopes, lenses, and lasers.

These devices are used in high-precision tasks where readings are taken within a single millimeter or even smaller. In tasks like this, voice coil actuators are excellent since they have no hysteresis that usually affects the accuracy of bi-directional movements.

The voice coils can also be assembled into multi-axis stages to control the X-Y or X-Y-Z motion of optics devices.

The voice coils have been generalized and are sometimes used to refer to galvanometer-like mechanisms that use solenoids to displace an object back or forth within a magnetic field.

Generally, it is commonly used to address a wire coil that moves the read or write heads of a moving disk drive. In this type of application, a low-weight coil of wire is mounted inside a strong magnetic field that produces earth magnets.

Advantages of Voice Coils

Overhung coils have a low to medium sensitivity due to their relatively higher coil mass. Furthermore, they show a soft nonlinearity when the coil exceeds working limits. Underhung coils also have a gap height larger than the coils’ height, which significantly keeps the magnetic flux constant.

Electrical & Electronic Components

Featured Industries