How do i use a dmm to find impedance?

[stay_high 10+ year member]

Tryed to google it and cant find much info on finding impedence of a sub using a DMM. Theres tons of info of how to set gains with it just not how to find impendance. Any help would be appreciated.

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[ahole-ic]

You can't. You can only find resistance with a digital multi meter. You do this by setting the multimeter to ohms. If it has a scale, set it on the 20 scale. This is the resistance of the coil and NOT the impedence. There is a difference and that is important to remember.

 

[stay_high 10+ year member]

You can't. You can only find resistance with a digital multi meter. You do this by setting the multimeter to ohms. If it has a scale, set it on the 20 scale. This is the resistance of the coil and NOT the impedence. There is a difference and that is important to remember.

Ok well im trying to find out if my 2 12's are wired to 1 ohm. I posted pics of the wiring on here and no one seemed sure. What is resistance exactly?

 

[ahole-ic]

Resistance is the value in ohms in a DC (direct current) circuit. Impedence is the value in ohms in an AC (alternating current) circuit. When you attempt to measure 1 ohm with your dmm, you will get a value OTHER than 1 ohm because you are measuring it's DC resistance. Not its AC impedence.

 

[Kangaroux 5,000+ posts]

Ok well im trying to find out if my 2 12's are wired to 1 ohm. I posted pics of the wiring on here and no one seemed sure. What is resistance exactly?

Exactly what it sounds like. Every circuit has resistance, some a lot, some a little. Resistance on subwoofers controls what load your amplifier runs at.

If you have your subs wired up, set the DMM to measure resistance (ohms), and attach the leads accordingly it will tell you what they are wired to. Sometimes it's not always on the mark. For example, my sub is a dual 2, but when I have it wired to 1 ohm it's 0.8 instead of being exactly 1.0

 

[kramer_212 10+ year member]

this help?

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[stay_high 10+ year member]

Exactly what it sounds like. Every circuit has resistance, some a lot, some a little. Resistance on subwoofers controls what load your amplifier runs at.
If you have your subs wired up, set the DMM to measure resistance (ohms), and attach the leads accordingly it will tell you what they are wired to. Sometimes it's not always on the mark. For example, my sub is a dual 2, but when I have it wired to 1 ohm it's 0.8 instead of being exactly 1.0

ok so then i can find out if there wired at 1 ohm with a dmm? So if it read .8 or close to 1 ohm that means that if i hook it up to my amp the amp will run at 1 ohm?

 

[stay_high 10+ year member]

Heres a pic of the wiring. If someone could look at one more time and tell me what they think that would be great. Other users that posted on that thread said 1 ohm. But other people have told me otherwise so im not sure.http://www.caraudio.com/forums/subwoofers/531092-how-these-subs-wired.html

 

[BnGRacing 10+ year member]

Resistance is the value in ohms in a DC (direct current) circuit. Impedence is the value in ohms in an AC (alternating current) circuit. When you attempt to measure 1 ohm with your dmm, you will get a value OTHER than 1 ohm because you are measuring it's DC resistance. Not its AC impedence.

^ this