Magnetic fields...

[Howard]

In a normal loudspeaker driver, the voice coil hangs between the pole piece and the top plate, and when current is run through it, its field is either attracted to or repelled from the magnet structure.

Now, my question is this: if a clone of the existing magnet(s) was attached above the top plate (a mirror image across the top plate) whose field orientation were reversed, would the field strength between the pole piece and top plate double? Or stay the same?

I think that the voice coil would then be pulled/pushed, rather than just one at a time, doubling the response time.

Thoughts on this?

 

[Eli]

Hmmm....

If it were that simple, they would have them.

 

[KingNothing]

You're probably going to get more intelligent replies if you ask this in Highly Technical.

^
The most intelligent reply I could muster.

 

[Howard]

Eli, with the additional magnets, price is going to go up. But then again, no audiophile drivers I know of use this technique.

 

[KMurphy]

No, the top plate you speak of is usually some sort of metal, which has much greater permeability than free air. The magnetic flux would pass completely through the top plate, thus negating any effect on the coil. What was your intention? To create a passive gain in power? Additionally, you would increase the impedance of the coil, limiting its response to changes in current which would lower response time. Your theory is flawed. Energy is not free, even though rare earth magnets can excite a field; it is typically very weak in comparison to the energy required to achieve the desired result.

 

[Howard]

Thanks for your input.

 

[silverpig]

I think you're sort of thinking of a humbucking speaker driver

Most single coil guitar pickups buzz somewhat, but humbucking pickups have two sets of coils right beside each other, wired oppositely and 180 degrees out of phase. They make the sound more accurate. It's sorta similar to what you're thinking of I guess, but not really.

 

[Cuda1447]

bump


it was lonely on page 15

 

[Howard]

What is the purpose of this?

 

[Howard]

^?