How do two layer voice coils work?

[Frosteh]

I understand how single layer/wound voice coils work, where the positive lead is at one end of the coil and the negative is at the other, but how do double wound coils work where both leads terminate at the top? See photos below for what I mean by double and single wound. On the double wound, wouldn't the electrical charge take the shortest route and not even charge the layers below the two leads since it would just go straight to the negative lead? What am I missing/not understanding?

Single wound:

Double wound:

 

[AlephZero]

Unless I completely musinderstood the question, you seem to be missing the fact that the wire is insulated. The insulation is a thin coat of material sprayed onto the wire which gives ithe shiry appearance. For this sort of application, you don't need thick flexible plastic insulation to protect the wire against mechanical damage and withstand repeated bending without cracking, whcih you see in most housefold electrical wiring.

 

[Frosteh]

Well gee, now I feel like a dunce. I wasn't aware that there was insulation on it! I thought copper wire was just that, copper wire. Now it makes sense. Thanks for clearing that up! :)

 

[davenn]

Well gee, now I feel like a dunce. I wasn't aware that there was insulation on it! I thought copper wire was just that, copper wire. Now it makes sense. Thanks for clearing that up! :)

dont feel too bad... its all a learning process :)

but also think about your reasoned comment ... if it was bare copper, even just a single layer would short out as well ;)

but note, bare copper wire is a very different colour, the colour you are seeing there, a dark, brownish colour is the enamel insulation on the wire.
then they dip the whole lot in lacquer to keep the turns of wire held in place
This form of insulation is used on most coils, be they transformers, plain inductors, voice coils as you have shown.
It is also common to see an almost transparent enamel used on more modern coils where the colour of the copper is somewhat more obviousDave

 

[alphysicist]

First of all, let's clarify the purpose of a voice coil in a speaker. A voice coil is a wire wound around a cylindrical former that is attached to the speaker cone. When an electrical current flows through the voice coil, it creates a magnetic field which interacts with the permanent magnet in the speaker, causing the voice coil and cone to move and produce sound.

In a single wound voice coil, as you mentioned, the positive and negative leads are located at opposite ends of the coil. When an electrical current flows through the coil, it creates a magnetic field that is evenly distributed throughout the entire coil. This magnetic field interacts with the permanent magnet to produce sound.

Now, in a double wound voice coil, both leads terminate at the top of the coil. This means that the electrical current flows through the entire length of the coil before exiting at the top. The key difference here is that the coil is wound in two layers, with the top layer wound in the opposite direction of the bottom layer. This creates a more complex magnetic field that is stronger and more evenly distributed, resulting in a more precise and powerful sound.

To address your concern about the electrical charge taking the shortest route, it's important to understand that the electrical current is flowing through the entire length of the coil, not just between the two leads. This means that both layers are being charged and contributing to the overall magnetic field. The leads at the top simply serve as the exit points for the electrical current.

In summary, a double wound voice coil works by utilizing two layers of wire wound in opposite directions to create a stronger and more precise magnetic field. The leads at the top serve as the exit points for the electrical current, but the current still flows through the entire length of the coil, charging both layers. This allows for a more powerful and accurate sound production. I hope this helps clarify any confusion.