Single Voice Coil vs. Dual Voice Coil. The Real Difference?


Single voice coils and dual voice coils are both commonly used in car speakers and especially in subwoofers.

They have different purposes, and also they each have their strengths and weaknesses. Everyone has their own opinion about which of these coils is better, and speakers with which one should you use for your car audio system.

All differences often lead to the question, what is the real difference between the single voice coil and dual coil?

Single coil speakers have one copper coil wrapped around the former in the speaker instead of two separate windings in a dual voice coil speaker. DVC speakers are more versatile and can be wired in multiple ways for varying impedance loads.

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There are multiple uses for dual voice coil speakers, and they are much more versatile than single voice coil speakers. While both speaker types are commonly used, let’s find out more differences between the dual voice coil and single voice coil speakers.

What’s the Purpose of Dual Voice Coils?

DVC vs SVC

For car audio, every speaker and amplifier is designed to run within certain specifications. If these requirements are not met, the speaker system will not function as well as it could.

A massive factor in wiring the speaker system correctly is impedance, measured in Ohms. The speaker’s impedance is the load that the speaker puts on the amplifier and the resistance that the speaker gives to the electrical signal.

The higher the impedance or the Ohm (Ω) rating, the less efficiently the signal can travel through the speaker.

The lower the Ohm rating, the more efficiently the signal can travel through the speaker, and the less signal resistance in the system is caused by the speaker.

Every amplifier is rated to work with specific resistance speakers, and most car audio speakers are built within these specifications.

The purpose of dual voice coil (DVC) speakers is they allow for more flexibility for how the speaker is wired into the system depending on the resistance required.

The dual coils within these speakers allow them to be wired as a single speaker with both stereo channels running through it, allowing one speaker to act as a stereo speaker. This is very useful, especially for older vehicles that are built with one central speaker rather than multiple speakers.

DVC speakers can be in parallel, which means that they reduce their load on the amplifier by half. A 4Ω DVC speaker wired in parallel will be reduced to 2Ω impedance.

This allows dual voice coil speakers to be wired with minimum impedance, allowing for the maximum output from the amplifier per speaker. Many car audio enthusiasts use this method to make their system really powerful and loud.

Dual voice coil speakers can also be wired in series, which will double the impedance of the speaker. This means that the speaker can be wired with an amplifier that required more impedance than it naturally has.

In short, the purpose of dual voice coil speakers is versatility.

DVC speakers can be wired to act as a single speaker that outputs stereo sound. Also, they can be wired to match the exact impedance required for the speaker system or for a particular amplifier, rather than being limited to only one impedance level that may be detrimental to a system.

What’s Better, Single or Dual Voice Coils?

Single voice coil (SVC) speakers and dual voice coil (DVC) speakers are commonly used for car audio.

The difference between these two speaker types is how they are wired and how they can be wired into a speaker system regarding their signal impedance and abilities to perform stereo signals.

There are many different opinions about SVC vs. DVC speakers, but which speaker is better?

The truth is, neither speaker type can be considered to be better than the other.

The speaker type you use should be based on your individual requirements and what you want to achieve from your car sound system.

SVC speakers are generally cheaper than DVC speakers, so they are better if you are on a budget. Use SVC speakers to build your audio system allows you to have more options to choose from when choosing speakers.

DVC speakers are more expensive, but they are much more versatile and are a great option if you are looking for one of the following:

  • to wire speakers in a very specific system
  • to achieve the absolute maximum output of your amplifier
  • be able to modify your speaker system easily in the future

The single voice coil and dual voice coil speakers operate at the same performance levels, so do not expect DVC speakers to perform better than SVC speakers when it comes to output or sound capabilities.

The difference between SVC and DVC speakers is not the speakers’ output or performance but rather how the speakers can be wired into a speaker system. So choose the type of speaker you use based on the system you are using or building.

How to Tell if Speakers Are DVC or SVC?

The difference between a DVC and an SVC speaker is usually relatively easy to see.

A dual coil speaker will have two sets of terminals, one for each coil within the speaker.

A single voice coil speaker will have one set of terminals only because the speaker itself only has one internal coil wrapped around the cylinder.

The terminals are the easiest way to tell if the speaker is DVC or SVC. The terminals are the connection points where the speaker can be wired into a system. These are either red and black plugs, ports, spring-loaded connectors, or access points on the speaker that receive wires from the system.

If the speaker is an SVC speaker, there will only be one set of terminals mounted on the speaker, rather than two.

If the speaker has no exposed terminals, which is very unlikely, then open the speaker and check for internal terminals. An SVC speaker will only ever have one set of the connection point, and they can be together or separated individually. In contrast, DVC speakers will always have two sets of connection points.

Do I Have to Use Both Voice Coils on a Dual Voice Coil Subwoofer?

When wiring a DVC subwoofer into a car audio system, it is important to use both coils.

A subwoofer that has only one coil wired into the system, essentially a subwoofer wired in series, will double the resistance of the subwoofer and significantly reduce its performance.

A subwoofer wired in this way is unstable and tends to distort. If only one coil in a DVC sub is used, it has an unbalanced frequency response, making it very difficult to EQ the subwoofer’s sound and set it up correctly for the perfect audio experience.

If only one coil is used, the system’s overall output will be drastically decreased, lowering the quality of the audio produced, even if the system is not pushed to the highest volumes.

This wiring of a subwoofer is why some car audio systems always sound distorted, even when used at low volumes. This will also lead to the sound quality of the system fluctuating wildly.

If you require a specific Ohm impedance from the subwoofer in a system, for example, if you need 4Ω resistance, using a 4Ω subwoofer wired in parallel (using both coils) will decrease the impedance and will not provide the necessary 4Ω resistance.

It is important to pair your hardware together correctly before purchasing it.

If you do run into this problem, if you need more resistance from your subwoofer in your audio system, run two identical subwoofers, both wired in parallel, and you will meet the required 4Ω resistance level.

Is a Bigger Voice Coil Better?

Using a speaker with a bigger voice coil comes with some advantages and disadvantages.

A speaker with a bigger voice coil is built with a bigger magnet to drive the coil, which means that the speaker has more power.

The more power a speaker has, the more dynamic the speaker can be and the more frequencies the speaker can produce.

A larger voice coil means that the speaker can produce better low frequencies, which require much more energy from the speaker to output them properly.

Using a speaker with a bigger voice coil will provide a better frequency response from the audio system, and you will more clearly hear all the frequencies present in the music, but it does draw more power from the amplifier.

A bigger voice coil does produce more power, which also means that it produces more heat. This is an essential factor that must be considered when mounting a speaker with a large voice coil in a sealed bass enclosure. You do not want the speaker to overheat and become damaged.

The voice coil will act as a heat-sync and help dissipate some of the produced heat, but it will not absorb all of the heat that it produces. These speakers still put off quite a lot of heat.

A bigger voice coil is better if you have fewer speakers in the system, as the frequencies that the system can output will be greater, and there will be much smoother transitions between the frequencies produced.

The only other option for producing the same level of performance and sound quality is to use more speakers in the system, having banks of speakers designed to output specific frequency rangers, rather than fewer speakers that can output all frequency ranges.

Having many speakers of smaller sizes that produce their own set of frequencies to fill up the spectrum will draw the same power from the amplifier. The benefit is that similar speakers are less difficult to be incorrectly wired. The downside is that not all amps can drive so many speakers, and this setup is much more expensive.

Can I Use 6×9 Dual Voice Coil Speakers in My Car?

In the past, in many vintage cars, there was only one speaker compartment in the front of the vehicle, and all of the cars’ sound was run through that one speaker.

This speaker is usually placed in the middle of the dash, and the original speaker used in many of these older cars is not generally very high quality.

6×9 is the standard speaker size for a center-dash, single speaker for most vintage cars, and is still a common speaker size in modern vehicles as well.

You can use 6×9 dual voice speakers in your car.

A 6×9 dual voice coil speaker is an excellent replacement for the single in-dash speaker for a vintage car.

Using a 6×9 dual voice coil speaker allows the original speaker cavity to be used without making space or cutting holes in the trim of the vehicle for additional speakers, as a dual voice coil speaker can be run as a single stereo output speaker.

This means that one speaker can be run as an output for both channels of a stereo sound system, allowing the speaker to play all of the sounds, resulting in a good quality audio experience, without missing any sounds or frequencies from one channel or the other.

Using only one 6×9 dual voice coil speaker may result in poor quality audio accuracy, so it is recommended that you run other speakers within the vehicle as well.

It is quite common for a 6×9 dual voice coil speaker to be used in the single speaker cavity of a vintage car to preserve the vehicle’s interior aesthetics instead of making holes in the trim for additional speakers.

But again, using only one speaker will never produce perfect sound, even if it is a dual voice coil speaker.

How to Wire Dual Voice Coil Speakers?

How to wire your DVC speakers mainly depends on the Ohm load that your amplifier requires, and in the majority of cases, it can be either 2 or 4 ohms.

Dual voice coil speakers can be wired in series or parallel. When using multiple DVC speakers, there are many combinations of wirings that can be used to match the impedance requirements of the amplifier in your system.

It all comes down to the impedance load that the amplifier requires. The speakers should be wired to match the amplifier’s impedance load, or the system will not function well.

For example, if you are using two 4Ω DVC speakers powered by a 2Ω impedance amplifier, the impedance of the speakers at the amplifier must be 2Ω.

To achieve this impedance rating at the amplifier, wire the DVC speakers in series. Connect one positive terminal to an opposing negative terminal for each speaker. This will leave one available positive terminal and one available negative terminal for each speaker.

The series connection will keep each speaker at a 4Ω load, and they can now be wired to create a 2Ω load at the amplifier.

To combine the two speakers to have a 2Ω load at the amp, connect all positive terminals of all speakers with the same positive amplifier terminal. The same should be done with all negative speaker terminals. All should be connected to the same amplifier’s negative terminal. 

This will produce a nominal 2Ω load from the speakers to the amplifier, matching the speaker impedance to the amplifier’s required impedance.

There are multiple ways to wire a speaker system that uses DVC speakers, but this is the most common wiring method for a two-speaker powered DVC speakers system.

Conclusion

DVC and SVC speakers are both commonly used for car audio systems.

SVC speakers are cheaper, but they have fixed impedance levels that can not be altered no matter how they are wired. These speakers are useful, but they must be matched perfectly to the correct amplifier and used correctly in the audio system.

DVC speakers cost more, but they are more versatile. They can be wired in different ways to alter their impedance load on the amplifier, and they can even be wired to output a stereo signal from a signal speaker.

Both SVC and DVC speakers have the same output and performance levels.

The difference between these two speaker types is their wiring configurations and connectivity variations.

When deciding between using DVC and SVC speakers, do not expect a difference in performance between the speaker type. Instead, use the speakers that best suit your system, requirements, and your plans for a perfect audio system in the future!

Martin

Welcome to ImproveCarAudio! I am Martin, and I love to write about everything related to car sound systems. I strive to provide the most accurate and helpful information about car audio through extensive research, as well as my experience with car audio installations.

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