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NoStoppin
10-05-2010, 03:01 PM
well I had a post up here earlier today, but then had the genius idea of calling JBL to ask them about heat and the alnico magnet. My 2214's seem to be rather lackluster compared to what they used to be.

apparently heat doesn't effect these to any extent, but time does. I have been directed to Orange County for re-magnetizing these 2214H's.

peace,
Tim O
Robh3606
10-05-2010, 04:24 PM
You normally do not have to re-mag Ferrite Magnets, Alnico yes.

Rob:)
badman
10-06-2010, 12:41 PM
You normally do not have to re-mag Ferrite Magnets, Alnico yes.

Rob:)

Though it's less about age and more about using too much power with them.
NoStoppin
10-06-2010, 02:46 PM
I wonder if heat would have deteriorated any components in the crossover? I'm sending mine to Duanedge for the upgrade to the T3 spec. After that, and having found this great article on Alnico magnets (http://vancouveraudiospeakerclinic.com/alnico.html), I'm quite sure it's time to get my drivers re-magged.

according to this article, it would require temps in excess of 1000F to even begin having a problem; hard knocks and bangs however can add up really quickly. Orange County Speakers charges $25 bucks a speaker, what a great deal!

peace,

Tim O
Robh3606
10-06-2010, 05:24 PM
Though it's less about age and more about using too much power with them.

For Alnico power would be an issue because they can be demaged during high current peaks. Ferrites are subject to de-mag from heat but it is temporary and they recover when cooled down. Take a look at the note Greg T wrote for us.

http://www.audioheritage.org/vbulletin/showthread.php?4031-The-Great-Alnico-Ferrite-Debate


Rob:)
ratitifb
10-07-2010, 04:09 AM
For Alnico power would be an issue because they can be demaged during high current peaks.see Eddy current ;) Usually woofers are mainly affected :(
badman
10-07-2010, 09:19 AM
For Alnico power would be an issue because they can be demaged during high current peaks. Ferrites are subject to de-mag from heat but it is temporary and they recover when cooled down. Take a look at the note Greg T wrote for us.

http://www.audioheritage.org/vbulletin/showthread.php?4031-The-Great-Alnico-Ferrite-Debate


Rob:)

You can partially demagnetize neo with heat, permanently, and ferrite with shock (impact), IIRC. Notice the heavy heatsinking on neo pro magnets. Shock, naturally, less of an issue :)