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Topic: cause of voice coil failures? |
Mike Shockley
From:
Lufkin, Texas, USA
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Posted 21 Jul 2008 5:42 pm |
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What causes voice coil failure?
I've been playing for 50 years and this is my 1st.
Anybody know?? |
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Steve English
From:
Baja, Arizona
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Posted 21 Jul 2008 7:00 pm
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Heat/energy is one culprit..
In some cases contamination, little things sticking to the magnet in the voice coil.
_________________
Always remember you're unique..... Just like everyone else |
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Danny Bates
From:
Fresno, CA. USA
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Posted 22 Jul 2008 12:25 am
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Square wave distortion from a solid state amp could be the culprit too. Basically, to reproduce a square wave, the speaker must go all the way in, to all the way out. While it does this, the voice coil can lose it alignment easy and hit the magnet and either short out or break the coil. Tube amp distortion isn't as likely to produce a square wave compared to a solid state amp.
When it gets fixed, the repairman will know which one it was. Ask them to report this info so you will know why you blew it up and hopefully not do it again.
Or you could have direct current (DC)coming out of your amp and it will fry any speaker you put in there. Basically, the DC is like your battery cables getting hot when you jump a dead battery. I think this is what causes the heat that Steve English mentioned. I think the energy he mentions is just too much power to the speaker. In that case, you might want to upgrade instead of replace the speaker.
I would ask an electronics expert like Chuck Fisher or Ken Fox because they might know other reasons besides the ones we mentioned. |
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Mike Shockley
From:
Lufkin, Texas, USA
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Posted 22 Jul 2008 4:22 am
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| Thanks Guys, I may have been pushing it to hard. |
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Jim Kennedy
From:
Brentwood California, USA
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Posted 22 Jul 2008 7:48 am
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I had a PA woofer go bad because their were to many chiefs and not enough indians. Speakers and mic's were getting plugged and unplugged and one of those pops you get hit the speaker just right. Plugging in and unplugging gear on a hot amp or PA can do more than just make noise. I now mute or tun off my gear before connecting or dis connecting anything.
_________________
ShoBud Pro 1, 75 Tele, 85 Yamaha SA 2000, Fender Cybertwin, |
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Larry Scott
From:
Virginia, USA
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Posted 22 Jul 2008 5:43 pm Re: cause of voice coil failures?
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| Mike Shockley wrote: |
What causes voice coil failure?
I've been playing for 50 years and this is my 1st.
Anybody know?? |
Our old freind Billy Ray 
http://www.youtube.com/watch?v=VFSlAqmpu94
He has not had a drop in 20 years.......MY  AXXXXXX |
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Donny Hinson
From:
Glen Burnie, Md. U.S.A.
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Posted 22 Jul 2008 5:56 pm
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Playing with distortion really puts a strain on the voice coil. The culprit is average power, which is way up when running this way, and the voice coil has no chance to cool. Amps (tube or transistor), can put out far more than their rated power when pushed into distortion.
Once, while trying to sound like Jimi Hendrix, I "cooked" a speaker rated at 200 watts RMS with a 60 watt B/F Twin Reverb. A mere 60 seconds of abuse made that speaker light up (literally) like a 100-watt bulb!  |
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Chuck Fisher
From:
Santa Cruz, California, USA * R.I.P.
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Posted 23 Jul 2008 4:58 pm
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my name was uttered so i will give a typically verbose technical littany.
Solid state amps frequently go DC when a output transistor/device shorts. amps in this condition can break a voice coil loose, sometimes denting or shorting it on the magnet structure. When you blow an amp or speaker keep this in mnd lest you dmage new speakers on a bad amp. turn on the amp with no speaker and measure the output for a DC offset. There should be little or no DC present across live output with no input signal.
sometimes old speakers just have voice coils just break glue joints due to age and vibration fatigue
solid state amps driven to distortion also emit spikes that damage voice coils , more frequently on tweeters. |
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