# Voice coil impedence



## Bopster (Feb 18, 2010)

I have a dual 4ohm VC speaker.
One VC measures 3.4ohm the other 7.2ohm.
This does not seem right????

Bop:scratch:


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## Anthony (Oct 5, 2006)

Hmm, that doesn't seem right, although DC resistance is different than the actual impedance load during operation. I would still expect them to be similar, though.

What is the brand and model?


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## Bopster (Feb 18, 2010)

Soundstream R-12SQ Rubicon

I am wondering if one of the VC's is bad. I have yet to fire it up and was measuring for modeling.

Bop


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## Anthony (Oct 5, 2006)

The only other thing I can think of is that the grounds were tied together and you accidentally measured both coils in series the second time (+ to +) -- but that is very unlikely; or this is the worst labeled driver ever.

My vote is for a bad VC, but hopefully others here can chime in. Can you measure the other T-S parameters? That might also be an indication of a problem if those are way off spec.


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## Bopster (Feb 18, 2010)

The terminals are on opposite sides of the driver. No chance at grounding while measuring.
Either to the other terminals or the speaker housing.
I am leaning to VC also.

Bop


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## dyohn (Apr 17, 2008)

Sounds like a bad VC to me. The DCR of both coils should be within about 10% of each other.


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## bambino (Feb 21, 2010)

I would agree with the rest of the folks on VC being bad. Hope it's under warrenty so you can get a replacement, good luck to ya.


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