Eeyore wrote:

"Michael A. Terrell" wrote:

Eeyore wrote:
N Cook wrote:
Michael A. Terrell wrote in message
That would be AWG 34 (143 TPI) or 35 (158 TPI), or British SWG 38 or
39. I don't see how it could handle 300 watts at 8 ohms.

Exactly my problem , I cannot square the blurb statement with analysed
physical reality.
Oh for heaven's sake guys, it's *force cooled* !

Certain manufacturers have also demonstrated their voice coils operating red
hot, the materials are that good.

Graham
Really? How do they maintain the impedance? The resistance would go
up quite a bit,

It does ! The effect is usually called 'power compression' and it can typically
knock up to 3dB off the speaker sensitivity with prolonged high power use. That'll
give you some inkling as to the temp rises involved.

Since such speakers are invariably used with 'active crossovers' on the inputs to
the amplifiers it doesn't cause any adverse issues with crossover responses.

The company that first made that 'red hot' claim was Precision Devices. You can
find a 1000W continuous rated speaker of theirs here.

http://www.precisiondevices.co.uk/showdetails.asp?id=17


and the insulation wouldn't last very long. It sounds
like another audiofools dream.

Kapton voice coil formers are now the norm for decent quality speakers.

I have *never* seen a purely thermal failure in any *modern* voice coil.

Graham


I`ve seen the pigtails melt before the voice coil does.

Ron(UK)

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