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Topic: Speaker Resistance |
Skip Ellis
From:
Bradenton, Fl USA
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Posted 24 Oct 2009 11:25 am |
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Approximately what dc resistance should I read when measuring an 8 ohm speaker? I've got a 15" out of an old Polytone bass amp that I thought about putting in a cabinet and using for an external speaker for my Roland Cube 60 which calls for 8 ohm. I thought the 15 might make the amp a little more suitable for steel.
Thanks!!
_________________
2022 Brook Lyn, 2014 Martin 000-18, 2022 Ibanez GB-10, two homebrew Teles, Evans RE200 amp, understanding wife of 49 years. 'Steeless' at the moment |
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Georg Sørtun
From:
Mandal, Agder, Norway
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Posted 24 Oct 2009 11:33 am
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| 6 to 7 ohm DC resistance is normal for 8 ohm speakers. |
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Ray McCarthy
From:
New Hampshire, USA
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Posted 24 Oct 2009 11:35 am
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| I don't believe you can determine the impedance of a speaker by measuring the DC resistance--the impedance would be determined by several factors, including the magnet's properties. If it is a 4-ohm speaker, It will allow the amp to produce a little more power, but it should work OK. |
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Skip Ellis
From:
Bradenton, Fl USA
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Posted 24 Oct 2009 11:43 am
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Thanks, guys!
_________________
2022 Brook Lyn, 2014 Martin 000-18, 2022 Ibanez GB-10, two homebrew Teles, Evans RE200 amp, understanding wife of 49 years. 'Steeless' at the moment |
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Greg Cutshaw
From:
Corry, PA, USA
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Posted 24 Oct 2009 1:32 pm
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You can see from this chart that the rated impedance of a speaker is 20% higher than the speaker's measured DC resistance.
Greg |
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Gary Jones
From:
Mount Vernon, Wa
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Posted 24 Oct 2009 1:51 pm
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The general rule of thumb is to measure the DC resistance of a speaker (with nothing else attached) and multiply that by 1.3, so an 8 Ohm speaker should measure around 6.15 Ohm dc.
Of course this is only a ballpark figure, but since musical instrument speakers usually only come in 4, 8, or 16 Ohm varieties, that measurement should be enough to tell them apart.
Here is a good article on speaker impedances. http://www.epanorama.net/documents/audio/speaker_impedance.html
Gary Jones
Yes, I'm still alive, I just smell funny. |
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