Talk:Voice coil

the cone has been known to tear off the cone????

Voltage and current in loudspeaker coils
The cone force (equivalent to cone displacement with a linear compliance) is proportional to the current. The induced (terminal) emf is proportional to the coil velocity. See Lenz law and Flemings rules.--Light current 17:39, 26 February 2006 (UTC)


 * I'd have said "eventual cone displacement" (to indicate that that would be the static end point rather than the dynamic situation) and "counter EMF", but otherwise, this is correct.


 * Atlant 19:59, 26 February 2006 (UTC)

Yes, but if you drive a coil with a sinusoidal lowish frequency current, is not the cone displacement proportional to that instantaneous current? (assuming a linear compliance of the surround) --Light current 20:54, 26 February 2006 (UTC)

Thumping noise
Does anyone know what this highly scientific term means and what causes it?--Light current 21:19, 4 March 2006 (UTC)


 * Are you referring to how speakers sometimes "thump" upon power-up (of the amp)?


 * Atlant 02:29, 5 March 2006 (UTC)

Probably thats what the author meant (an effect due to excessive current).--Light current 02:33, 5 March 2006 (UTC)


 * Probably due to the various parts of the amplifier train powering up in an unexpected order and amplifying a unintended DC offset to full-scale that causes the speaker to be driven to one of the extremities as the system stabilises. Numerous amplifiers have a relay that leaves the speaker output disconnected during power-up to mask this behaviour.
 * Idyllic press (talk) 09:01, 4 August 2015 (UTC)

aluminum rings
"Some magnet designs include aluminium rings above and below the magnet gap, to improve conduction cooling, significantly improving power handling." I don't have the reference handy to feel comfortable deleting this right now... but IIRC the aluminum rings are not for cooling. They are to dampen a certain motion or magnetic field. The ring appear as a shorted coil to the moving coil and the current induced in it counter-acts the field generated by the voice coil. The field from the voice coil otherwise adds and subtracts from the field in the gap (created by the permanent magnet). Marvin Glenn 08:38, 9 October 2007 (UTC)

Pretty pictures
I find it amusing that there are no images of voice coils in this article. Perhaps I will take a few this evening and upload them - maybe one picture with a variety of coils, and a ruler or something to indicate approximate sizes? Huw Powell (talk) 22:40, 4 December 2008 (UTC)
 * Take ya two and a half years to choreograph that photo right :)

Daniel Christensen (talk) 06:40, 8 July 2011 (UTC)


 * Good picture, notice the clear slit in the aluminium bobbin to minimise eddy current losses/heating.
 * Idyllic press (talk) 09:06, 4 August 2015 (UTC)

voice coil is an important part of loudspeaker.
I just entered in this line,from a Chinese girl Hailey. —Preceding unsigned comment added by 116.4.4.221 (talk) 02:04, 20 October 2009 (UTC)

Over hung coil con
I wonder if it is a real problem or my imagination.

When a coil (or part of it) is locked or out of the air gap it will be generating no back EMF, this will effectively reduce the speaker impedance to it's DC resistance. This could potentially be much less than expected resulting in overheating. Is this a real problem with the over hung coils or is this just paranoia?

Idyllic press (talk) 09:04, 4 August 2015 (UTC)