Before we can explain what dual voice coil speakers are, you first have to understand what a voice coil is and how a speaker works. All speakers have what is called a voice coil. The voice coil is a coil of wire wrapped around a cylinder that accepts the current from the amplifier. This current causes the voice coil to react with the speaker magnet which moves that cylinder up and down. The speaker cone is attached to the cylinder which produces air pressure when it moves creating sound.
A standard speaker has only a single voice coil and are perfect for standard stereo setups using multiple speakers. These are called single voice coil (SVC) speakers. A dual voice coil (DVC) speaker is a little bit different. A dual voice coil speaker has two voice coils that allow a single speaker to output both stereo channels through one speaker, creating a stereo sound from a single speaker location. Many classic cars came with only one speaker installed in the dashboard. Dual voice coil speakers are perfect for replacing a standard dash speaker, because they allow both stereo channels to come through from a single location.
Another advantage that a dual voice coil speaker has over a standard speaker is more control of impedance depending on how you wire it. A standard speaker can only be wired one way, but with a dual voice coil speaker you have much more flexibility.
For example, the standard wiring technique for a dual voice coil speaker is to wire with both channels in as left and right speakers – which uses both voice coils for a stereo mix:
Another method is to wire both voice coils in series. This will make the voice coils work together to create a 8 ohm mono speaker (most older dash speakers were mono 8 ohm or 10 ohm speakers):
RetroSound® offers many different sizes of dual voice coil speakers. For more information about different types of speakers, visit the following link: https://www.retromanufacturing.com/pages/speaker-basics.