• 09-15-2005, 13:38
    littleangrygiant
    Anyone know how to check speaker polarity with a multimeter?
    i recently added a 4 channel amp and i need to make sure that i have the polarity right on my speakers. i read on a post somewhere that if you set the mm to volts and put the leads on the speaker terminals (+ to + and - to -) you would be able to tell. it said if the voltage goes neg, then polarity is reversed. that didnt make sense, but i thought id try it. didnt work. always said 0 volts. does that mean play music then put the mm on the terminals while the music is playin? then check if the voltage is pos or neg? all i can find is people sayin put a battery on the terminals, but my speakers are behing the door panels and under the rear deck so i cant see if theyre in or out when the battery is on them. any help? if anyone knows, im sure you guys know.
  • 09-15-2005, 14:12
    Easy E
    You use a battery. Hook positive to postive, and negative and negative. The cone will move out if its hooked up right, if not it will move in meaning the polarity is reversed.
  • 09-15-2005, 14:55
    littleangrygiant
    Quote:

    Originally Posted by Easy E
    You use a battery. Hook positive to postive, and negative and negative. The cone will move out if its hooked up right, if not it will move in meaning the polarity is reversed.

    yeah. i got that part. but you see, the speakers are covered. inside the door panels, and under the rear deck. i cant see if they move in or out. any more suggestions? thanks
  • 09-15-2005, 16:32
    Easy E
    Quote:

    Originally Posted by littleangrygiant
    yeah. i got that part. but you see, the speakers are covered. inside the door panels, and under the rear deck. i cant see if they move in or out. any more suggestions? thanks

    Rip open the doors and rear deck ;)
  • 09-15-2005, 19:16
    CVStroker
    You're testing it right, just not reading it right. It will say 0 volts no matter what. It depends on whether is says 0 volts or -0 volts, if it says -0 volts, then the one you have the positive probe touching is the negative wire. Remember, this only works with a digital multimeter, if you have an alalog multimeter (refering to the kind of display) it wont work.
  • 09-16-2005, 00:37
    Easy E
    Quote:

    Originally Posted by CVStroker
    You're testing it right, just not reading it right. It will say 0 volts no matter what. It depends on whether is says 0 volts or -0 volts, if it says -0 volts, then the one you have the positive probe touching is the negative wire. Remember, this only works with a digital multimeter, if you have an alalog multimeter (refering to the kind of display) it wont work.

    Nope will read 0 volts cause its a impedence load not a electric load.
  • 09-16-2005, 12:09
    littleangrygiant
    Quote:

    Originally Posted by Easy E
    Nope will read 0 volts cause its a impedence load not a electric load.

    so, if i set the meter to ohms, will it say -4ohms if its out of phase or will it just say 4ohms no matter what? it seems that there should be an easier way than to tear the car apart. :confused:
  • 09-16-2005, 14:40
    CVStroker
    Quote:

    Originally Posted by Easy E
    Nope will read 0 volts cause its a impedence load not a electric load.


    Oops, sorry, my mistake, I was looking at my multimeter wrong.
  • 09-16-2005, 14:47
    littleangrygiant
    Quote:

    Originally Posted by CVStroker
    Oops, sorry, my mistake, I was looking at my multimeter wrong.

    so, do i set it for voltage or impedance? im really quite confused by this. i just dont wanna tear apart my interior.
  • 09-17-2005, 10:02
    Easy E
    Quote:

    Originally Posted by littleangrygiant
    so, do i set it for voltage or impedance? im really quite confused by this. i just dont wanna tear apart my interior.

    Only way is to pull the interior apart...
  • 09-18-2005, 23:58
    Eventix
    You dont have to pull the interior if you are careful and have a grill covering the speaker. This method will not work for small speakers but if your testing 5" or larger you can probably get by. The seaker should move in or out depending on the polarity of the battery test. I think the speaker moves out if you have the batteries positive to the speaker positive and reverse for battery positive to speaker negative (someone confirm this for me). Have a friend touch the wires while your holding something slender enough to slide through the grill against the cone (don't put a hole in the speaker) and feel if it moves out or in.

    not possible to have a negative resistance and you probably need an oscilloscope to find out the polarity while speaker are in use. A multimeter alone is not going to help you.