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Topic: Miss match? |
George McLellan
From: Duluth, MN USA
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Posted 20 Sep 2019 6:54 am
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My amp says 8 ohms on the external sport jac, I’ve been using a black widow speaker. It seems to work just fine but I’m wondering if it makes any difference if the speaker is 8 or 4 ohms, I can't find any markings on the speaker.
Geo |
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Donny Hinson
From: Glen Burnie, Md. U.S.A.
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Posted 22 Sep 2019 6:03 am
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The speaker in the amp is probably an 8-ohm, so adding another 8-ohm speaker would pull the total load down to 4-ohms. (Apparently, that's what the manufacturer is recommending as a minimum.) But if the additional speaker was 4-ohms, the total load would drop down to 2.67 ohms, which is pretty low. Now, you might get away with that if the volume was kept low and you weren't driving it hard. But if you pushed the amp, you'd be risking overheating the output stage, and it might burn something out.
I'd get a cheap multimeter and check the resistance of the additional speaker just to be safe. (About $10 at Harbor Freight.) The DC resistance is always slightly lower than the rated impedance, so a speaker that measures around 6 ohms DC resistance is likely 8-ohms impedance, and one that measures around 3 ohms resistance is likely a 4-ohm speaker.
Hope that helps! |
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George McLellan
From: Duluth, MN USA
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Posted 22 Sep 2019 6:46 am Thank you
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Thanks Don. That’s what I wanted to find out. The speaker is a Black Widow so I can assume it’s 4 ohm as that’s the only ohm I’ve heard of.
Geo |
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Jonathan Cullifer
From: Gallatin, TN
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Posted 23 Sep 2019 7:02 am Re: Thank you
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George McLellan wrote: |
The speaker is a Black Widow so I can assume it’s 4 ohm as that’s the only ohm I’ve heard of.
Geo |
There are several 8 ohm Black Widows, like the 1201-8.
I would disconnect the speaker and measure its resistance to verify. |
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Travis Wilson
From: Johnson City, TX
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Posted 23 Sep 2019 8:11 am
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If you wire you speakers in parallel it halves the impedance, if you wire in series it doubles it. Eg 2x8ohm parallel=4ohm; 2x8ohm series 16ohm |
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b0b
From: Cloverdale, CA, USA
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Posted 23 Sep 2019 2:57 pm
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Travis Wilson wrote: |
If you wire you speakers in parallel it halves the impedance, if you wire in series it doubles it. Eg 2x8ohm parallel=4ohm; 2x8ohm series 16ohm |
External speaker jacks are never series. Almost all are parallel. The rare exceptions have a separate transformer coil or power amp.
Series wiring (which increases impedance) is only used internally in multi-speaker extension cabs. _________________ -𝕓𝕆𝕓- (admin) - Robert P. Lee - Recordings - Breathe - D6th - Video |
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George McLellan
From: Duluth, MN USA
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Posted 25 Sep 2019 5:31 am It’s 8 ohm
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Thanks Jonathan. I found a small tag by the terminals. It states. “1504 8 ohmâ€.
Geo |
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