DMM / polarity?

whats the best way to use a dmm to find out polarity? lets say on factory speaker wires on a door with or without the hu hooked up. i think i do it right but could always use advice.

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owner of
Motion Marine & Car Audio
the florida keys

are you checking the speaker it self or the wiring.. the wiring just hook up your dmm to the two leads and if the number is positive then its correct if negative you have your leads back wards. the speaker just use a 9v battery and test if the cone goes out then you have the leads correct if it goes in then you have the leads reversed.

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Quad L Handyman services

Thise are correct steps, but you can't really use a DMM to check polarity on a speaker lead, it is an AC output, and the DMM will just say "THIS MANY VOLTS", without regard to polarity...

...and if you are worried about hurting the drivers by hooking them up "backwards", you can't... BUT if you hook one up "backwards" make certain you do it to ALL of the speakers in the system... this is called "absolute phase", and as long as they are all in "absolute phase", all is good, otherwise you get some really weird, and usually unpleasant, (difficult to explain in type) effects in your overall sound.

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

if you have a aftermarket HU, you can plug in the HU harness and look at the leads on the factory side....

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If we learn from each success and
each failure, then we can improve ourselves