Nine.1 amp running at 1.5 ohms instead of 1?

[ls1pimp 10+ year member]

The shop that installed my system measured the sub impedance of my RE XXX before and after they installed it, to make sure they wired the sub how I wanted. But they told me that before and after it was reading about 1.5 ohms on the voltmeter? Is that normal? Shouldn't it be reading 1 ohm? //content.invisioncic.com/y282845/emoticons/uhoh.gif.c07307dd22ee7e63e22fc8e9c614d1fd.gif

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[CBFryman2 5,000+ posts]

Not nessicarily. What's the RE of the coils? If it is wired to 1ohm nominal it should be below 1ohm DC resistance.

 

[djman37 5,000+ posts]

crappy dmm?

 

[adas Pro Seller]

Shouldn't it be 1.5 ohms per coil(?) If it's at 1.5 ohms wired to 1 ohm, that kinda sucks:crap:

I need to measure mine, I'll do it later today(you talkin about 06 xxx right?)

 

[acold7dusta 10+ year member]

when you wire a sub down to 1 ohm, thats just its nominal value. at different frequencies, the impedance will vary slighty, with the greatest difference being where you tuned your box

do some searches on impedance rise for more info

 

[CBFryman2 5,000+ posts]

Touch your leads togather and read the resistance before measureing the DCR of the speaker. Subtract what you got from touching them togather from what you get when you measure the speaker...

I really hope you wherent that lost but just incase.

 

[helotaxi 5,000+ posts]

You also aren't measuring the impedance, but rather the DC resistance and they are different.

 

[SAG3 5,000+ posts]

Your amp will blow.

 

[BassAddictJ 5,000+ posts]

Touch your leads togather and read the resistance before measureing the DCR of the speaker. Subtract what you got from touching them togather from what you get when you measure the speaker...
I really hope you wherent that lost but just incase.

this is correct. most all multimeters will have an internal resistance of anywhere between .4ohms and .7ohms +/-........see what urs reads, then subtract that from the measured coils, this value is the DCR (direct current resistance iirc, may be off by a word lol). the actual imp changes with the position fo the cone, as well as with the power being given and inefficencies/added resistance. you'll notice when you move the cone you dmm will go crazy, but then return to normal when the cone is stationary....

dcr vale of coils (re's included), are a little under thier rated imp value. the rating you get is the "nominal" and is close to what the amp should be seeing as a reactive load, though impedence rise is a *****, especially with spl....

2ohm nominal = 1.4ohm dcr

1ohm nominal = .7ohm dcr

.5ohm nominal = .35ohm dcr

.25ohm noiminal = .175ohm dcr

or at least very close to these values.....