DMM and VC Q

[saywhat? 5,000+ posts]

when using a DMM , if the sub is blown (coil wise) will it measure anything specific or will it just read zero? im trying to see if the sub i have is good to put in my brothers car (old eclipse black cone ??81244?? or something like that. it had a black alluminum cone with eclipse ghosted on it. deffinately an SQ sub, and thats how i plan on using it. but what will the DMM read (if anything) when i plug it up if the coils are blown?

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[InhumanAcura 5,000+ posts]

should read a bit above or below the nominal impedance..

if the coil is bad, you'll know it

 

[saywhat? 5,000+ posts]

well when i wired up my type r for a two ohm load it read 2.3 .............................

 

[InhumanAcura 5,000+ posts]

well when i wired up my type r for a two ohm load it read 2.3 .............................

keep in mind that 99% of subs dc resistance differs from the nominal impedance..

for instance the re dual 4 is a dual 2.8...dual 2 is a 2.6, dual 1 is a .7 etc..

on top of that, chances are the dmm is a tenth or 2 off

 

[saywhat? 5,000+ posts]

alright. so ur sayin that a dual 4 ohm sub is actually a dual 2.8....

 

[InhumanAcura 5,000+ posts]

alright. so ur sayin that a dual 4 ohm sub is actually a dual 2.8....

for that particular manu. though...i cant recall ever coming across a sub thats dcr was identical to the nom imp....might not be such a difference as the example, but 99% chances are it will differ a bit

 

[amedeuce 10+ year member]

alright. so ur sayin that a dual 4 ohm sub is actually a dual 2.8....

It's not an exact measure of impedance, if you leave the DMM on the coils you could see the numbers move up and down. A dual 4 ohm sub could read 3.8 or 3.2 or whatever.

 

[InhumanAcura 5,000+ posts]

It's not an exact measure of impedance, if you leave the DMM on the coils you could see the numbers move up and down. A dual 4 ohm sub could read 3.8 or 3.2 or whatever.

the resistance shouldnt move if the cone stays still. If you even breathe on it, it'll change drastically.

 

[amedeuce 10+ year member]

the resistance shouldnt move if the cone stays still. If you even breathe on it, it'll change drastically.

You're right, I meant as soon as you touch the ends of the DMM to the subs terminals it may take several seconds to get the reading and even then it won't be the same every time.

 

[InhumanAcura 5,000+ posts]

You're right, I meant as soon as you touch the ends of the DMM to the subs terminals it may take several seconds to get the reading and even then it won't be the same every time.

gotcha, tis true..

i actually saw a pic someone posted of an odd # they were getting with the dmm sitting on the cone lol

 

[squeak9798 5,000+ posts]

dual 2 is a 2.6

And RE is the only company I've seen who has a DCR higher than the nominal impedance.