Hi Todd, great to see you.
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Hi Todd, great to see you.
No yours won't if they are GPA's.. Those numbers on the inside lip of the voice coil are Altec part numbersQuote:
Originally Posted by alancohen
Thanks, OG!
Hi Todd, sorry I don't know who Bill Hayes is? Was he an Altec employee or an Altec engineer? What I was told is not so much a change in the design but rather a change in supplier of the materials used to manufactur.. a better metallurgic mix if even by accident. Now I'm not sure if this is Urban legend or what.. just digging for confirmation/information. As to crossovers they are new GPA manufactured xovers designed by them for use with the 16ohm 604's. The listening tests were conducted with my face planted squarely infront of the speaker about a foot away.. moving back and forth between speakers and replaying certain passages over an over again for comparisons sake.. all other factors are the same. Speaker leads were swapped back and forth between mono block amps etc..Quote:
Originally Posted by Todd W. White
also in regards to magnetic loss.. this is copied from audio asylum forum and I have read and heard much the same elsewhere.
Actually, if not abused, they should last almost forever. After a magnet stablizes, the loss of magnetic strength is on the order of 1% per thousand years. Its rare for loudspeakers used in a home environment to be run at the levels that would cause demagnetization of the magnets. This is usually only seen in commercial venues that run systems at full rated input levels for long periods of time. And even then, its not as common as you would think, going by all of the repeated mis-information you always find on the internet. Take your loudspeakers outside, away from sources of reflections, and feed them the same input level with a signal generator, and measure the sound level of both, from the same fixed distance. If they measure reasonably close to each other, I would not worry any more about it.
another copy paste on the same subject..
Google up Alnico or Cobalt You will soon read that Alnico is projected for a 2,000 year Life before mag field Fluz degradation is significant.
ANYONE selling/pushing Re-Zap is either a Fool or just wants yer $$.
Bill was Director of the Acoustic Laboratory from 1958 or so through 1983. He was also an employee there from the late 40's, and worked for John K. Hilliard and Alex Badmaeiff. Brilliant, yet humble guy.
He said they routinely tested the diaphragms and would have noticed any measurable changes.
I don't care what the Audio Asylum (aptly named) folks say - Alnico V magnets used in speakers DO lose magnetism over time. This is measurable and can be easily demonstrated.
This is one of the best things about AUB - these wonderful factoids from the people who know.
There are some holes in your reading. Alnico CAN be discharged by impact. Most writers are NOT engineers, and don't fully understand things. Add to that that even among experts there are differences in opinions. Life is not cut and dried. My engineering degree did teach me that there is way more to learn. The fool is the one who thinks he fully understands an extremely complicated universe.Quote:
Originally Posted by HeathKitPat
GPA does not charge for remag when reconing AFAIK.
Quote:
Originally Posted by HeathKitPat
No they don't.. Re-mag is free with a recone or a diaphragm replacement. I have a couple pair of 416's that benefited from re-mag. :smile2:Quote:
Originally Posted by Old Guy
I would think Heat would be another factor that can degauss a magnet, but don't quote me.
Google "Curie Temperature". :DQuote:
Originally Posted by cradeldorf