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How to measure voice coil resistance?


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I have a DVC power acoustik mofo. Since it's a power acoustik... I don't really trust their specs.

How can I measure the resistance of a coil?

And a side question: what is typical box rise?

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get a 9 volt battery, 2 long pieces of wire, a clamp meter, and a volt meter.

connect one wire to the neg of the coil and the neg of the battery, connect the positive to the pos of the coil and pos of the battery, set the clamp meter to dc current, and the volt meter to dc volts. get the current off the clamp meter, we'll call it "I" and the volts from the volt meter, we'll call it "V". now divide V by I and youll get R or your resistance of the coils

or a quicker way would be get a dmm and set it to measure ohm and itll pop right up on the screen,

and there is no "typical" box rise

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I should add that I don't have a clamp. If I hook up my DMM right to one of the coils, it measures zero and changes if I tap the sub.

And let me clarify my box rise question: I want to wire the sub to 2 ohms, but my amp is rated for 4 ohms and I was wondering if I could safely have it wired. If I had a clamp, then it wouldn't have a problem - but I don't. :(

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If its rated at 2 ohms per coil (dual voice coil means there's two of them) then your possible wiring options are 1 ohm, and 4 ohms. Its generally not a good idea to wire below the lowest rated stable ohm load of your amplifier.

If your ohm load is 0 but changes when you tap the sub you've either hooked up the DMM incorrectly, have a dead coil, or have a poor connection from the DMM to the sub terminals.

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Not to mention, not every coil is going to read exactly 2ohms for a D2, 1 ohm for a D1, S1, etc. Power Acoustik does exaggerate certain points, but coil resistance isn't something I would be too worried about, lol.

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I feel like I had a brain fart. I kept on wondering what I was doing wrong / checking the sub, etc... It turns out that my ancient voltmeter has a loose connection on the ohms terminal.

I used my friends multimeter to debug and it reads the resistance just fine. Its exactly 4.0 ohms

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