checking speaker ohms
Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=121992
Printed Date: May 23, 2024 at 10:55 AM
Topic: checking speaker ohms
Posted By: rt jam
Subject: checking speaker ohms
Date Posted: May 24, 2010 at 9:14 PM
Does your ohms reading jump around when you move the speaker cone?
Replies:
Posted By: anonymous1
Date Posted: May 24, 2010 at 9:17 PM
Are you asking if this is possible or normal? Yes, it can happen. It has no bearing on the information you need by measuring the coil. ------------- I know just enough to be dangerous. VERY dangerous.
Posted By: i am an idiot
Date Posted: May 24, 2010 at 9:32 PM
yes a moving speaker will make huge fluctuations in your meter reading. HUGE it does not even have to be visible motion. when a speaker that is not being driven by some source of power, it is now a microphone, any sound it hears moes the voice coil and this causes the coil to produce voltage, this fluctuation in voltage will make your meter swing severely, from near a dead short to probably 5 times it's actual resistance.
Posted By: rt jam
Date Posted: May 24, 2010 at 9:52 PM
Thanks for explaining it. I first noticed it one a sub set up I'm not happy with, then when I checked some other speakers, they also moved around.
One pair I was checking was my Kicker Solobaric S12C's. One measured 8 but the other was 92 ohms. Does this mean it's blown?
Posted By: roadshop570
Date Posted: May 24, 2010 at 10:15 PM
If you are getting an inconsistant reading that high, reconfirm with another meter and if its the same then yes you have a blown voice coil.
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Chadillac
Posted By: rt jam
Date Posted: May 25, 2010 at 7:34 PM
I have a pair of Kicker Solobaric s12c subwoofers. One subwoofer measures 8 ohm, the other is measuring 92 ohms. Does this mean it's blown? Why not an open circuit?
Posted By: roadshop570
Date Posted: May 26, 2010 at 8:23 PM
Never had issue with open circuit if im checking the voice coil with sub out the box, check for any breaks at the terminal all the way inside the basket, but still sounds blown. I never recommend using just one side of speaker vc but has worked many times.
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Chadillac
Posted By: i am an idiot
Date Posted: May 26, 2010 at 8:39 PM
A 92 ohm reading would lead me to believe that there is a problem with that coil. You can safely use one voice coil of a dual voice coil woofer. The speaker will handle around 75 percent of it's rated power handling.
Posted By: rt jam
Date Posted: May 26, 2010 at 9:38 PM
Another thing I forgot to mention. The 92ohm speaker seems to works well. They are wired in parallel and both speaker move the same, sound decent but that odd ohm reading.
Posted By: i am an idiot
Date Posted: May 26, 2010 at 10:23 PM
Connect only the 92 ohm coil. Does it play like that?
Posted By: rt jam
Date Posted: May 27, 2010 at 3:17 PM
Yes. I during the test it was wired up to the amp by itself. Then the other one, by itself. So each speaker by itself will work. This was not installed in the box at the time. So it's not the air pressure in the box influencing the movement. They seem to sound the same too.
So everything seems ok except for the ohms reading.
Posted By: i am an idiot
Date Posted: May 27, 2010 at 4:30 PM
Connect ONLY the 92 ohm coil. Not the woofer with the 92 ohm coil, connect only the coil that reads 92 ohm.
Posted By: rt jam
Date Posted: May 27, 2010 at 9:54 PM
I"m not sure I understand what you are saying to do.
These only have one pair of connections. A POS and a NEG. An ohms reading across the 2 connections on my left speaker reads 92 ohms.
The right speaker is 8 ohms.
The parallel wiring is outside the box. There are 4 connections. 2 for each speaker. They are wired parallel outside the box by gold or metal strip between the 2 positives and one between the 2 negatives.
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