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View Full Version : Could someone from sundown confirm if this is normal (SA8v2 d4 reading 3ohms)



htownrsx
02-24-2013, 01:24 AM
Hello,

I just want to make sure before I install my subs today, that this is indeed normal. I just received these bstock sa8v2s, and checked them via dmm.
http://i.imgur.com/kd9S3P7.jpg
Thank you,
Rob

mylows10
02-24-2013, 01:34 AM
might be why they are b stock

htownrsx
02-24-2013, 01:41 AM
might be why they are b stock

Is this going to affect the performance? I mean they will not receive the correct amount of power?

mylows10
02-24-2013, 01:44 AM
Is this going to affect the performance? I mean they will not receive the correct amount of power?

depends on if both coils are reading 3 ohms or not and how you wire them to the amp. i'd say that the coils are damaged ,usually the 4 ohm coils wont read that low ,but maybe not to bad ,they may still work for a while like they are .

Popwarhomie
02-24-2013, 01:44 AM
Sure your Multimeter is correct?

Isnt there a trick to testing them? Touch the - and + together and take the reading and + or - the difference from what the coil is reading? :confused:

htownrsx
02-24-2013, 01:45 AM
I'm pretty sure that the dmm is accurate, bc I also have a brand new sa8v2 dual 2, which reads a perfect 2 ohms each coil via the same dmm. The readings are the same for both of my d4s, across all coils.

hispls
02-24-2013, 01:46 AM
might be why they are b stock

Not likely. More likely OP has an inaccurate DMM or that's just how the coils are on them. Really if all the coils are done with the same wire, with the same length, and same number of turns, how could a coil be different from the next?


Is this going to affect the performance? I mean they will not receive the correct amount of power?

It's fine. Very few woofers DC resistance is the same as nominal impedance.

htownrsx
02-24-2013, 01:47 AM
depends on if both coils are reading 3 ohms or not and how you wire them to the amp. i'd say that the coils are damaged ,usually the 4 ohm coils wont read that low ,but maybe not to bad ,they may still work for a while like they are .

Aren't b stocks supposed to be mechanically fine, just minor scratches or blemishes?

htownrsx
02-24-2013, 01:48 AM
Not likely. More likely OP has an inaccurate DMM or that's just how the coils are on them. Really if all the coils are done with the same wire, with the same length, and same number of turns, how could a coil be different from the next?


It's fine. Very few woofers DC resistance is the same as nominal impedance.

I'm just trying to understand, since i'm pretty new to car audio. I wouldn't think it's too big of a deal, but the exact same dmm reads my dual 2 sa8s @ exactly 2.0 ohms.

mylows10
02-24-2013, 01:49 AM
Aren't b stocks supposed to be mechanically fine, just minor scratches or blemishes?
not always ,some have mechanical issues also .most d 4 subs read usually around 3.6 not at 3 ohms

htownrsx
02-24-2013, 01:53 AM
not always ,some have mechanical issues also .most d 4 subs read usually around 3.6 not at 3 ohms

This is the description of the open box subs that I purchased, from the companies website:
"Open Box Value! These are Sundown B-Stock. The woofer may have cosmetic flaw like excesive glue or scratch on backplate of magnet."

I really don't want to mount and install, and have something go wrong.

esmokah
02-24-2013, 01:55 AM
They are FINE. when you measure a voice coil, you are measuring it's RE value (coil resistance) this is listed on the SA website of being 3.3ohms.

This is different from the 4 ohm impedance rating.

This is the second time i've answered this question this weekend on this forum.

htownrsx
02-24-2013, 01:58 AM
The only problem I have with your answer is that my brand new sa8v2d2 reads 2.0 ohms, while the website says that the RE is 3.36 ohms. So are you saying that my brand new sa8v2 D2s are supposed to read 3.36 ohms as well?


They are FINE. when you measure a voice coil, you are measuring it's RE value (coil resistance) this is listed on the SA website of being 3.3ohms.

This is different from the 4 ohm impedance rating.

This is the second time i've answered this question this weekend on this forum.

esmokah
02-24-2013, 02:05 AM
by 2.0 i assume you mean 3.0, as pictured.

do you know how much .36 ohm is? not enough to be concerned with where you're going! you would have a real hard time trying to find a sub that isn't that far out of tolerance one way or another. if it were a direct short or something way off, then yes, you would have something to worry about. hook em up and enjoy.

when you wire them all up to a one ohm load on your amp, that RE reading will only be off by .09 ohms. That's off by less than a c*nt hair.

(.36 / 4 = .09)

htownrsx
02-24-2013, 02:09 AM
I actually have a pair of brand new sa8v2 dual 2 ohm subs, which I measured @ 2.0 ohms each coil. I was just thinking that 3.0 is pretty close to the dual 2, which makes me believe that there would be some sort of negative affect to wiring the dual 4ohms @ 1 ohm.


by 2.0 i assume you mean 3.0, as pictured.

do you know how much .36 ohm is? not enough to be concerned with where you're going! you would have a real hard time trying to find a sub that isn't that far out of tolerance one way or another. if it were a direct short or something way off, then yes, you would have something to worry about. hook em up and enjoy.

mylows10
02-24-2013, 02:12 AM
prolly fine , maybe jacob will see this and chime in .in any acct sounds like your ok

esmokah
02-24-2013, 02:19 AM
so you have a set of d4s and a set of d2s? the d4s are reading 3 and the d2s are reading 2?

htownrsx
02-24-2013, 02:23 AM
That is correct.


so you have a set of d4s and a set of d2s? the d4s are reading 3 and the d2s are reading 2?

esmokah
02-24-2013, 02:30 AM
I bet it's a typo on the site saying the d2 should have 3.36 re. I still think you are good2go on all of those drivers.

htownrsx
02-24-2013, 02:32 AM
Ok cool. I would just like someone like Jacob to reassure that it is indeed ok, not that I don't trust you!



I bet it's a typo on the site saying the d2 should have 3.36 re. I still think you are good2go on all of those drivers.

esmokah
02-24-2013, 02:40 AM
I wouldn't trust me either. I installed my whole system myself and I don't even have a dmm. ;)

Happy Bumping

momax_powers
02-24-2013, 06:57 AM
Ok cool. I would just like someone like Jacob to reassure that it is indeed ok, not that I don't trust you!

i just tested both of my sa8v2 d4
DDM with no load = 0.3 ohm
DDM on each coil separately = 3.3 ohm (both subs yielded same results)
Therefore all coils are 3.0 ohm

i think you are fine