Impedance rise

[Mr FaceCaser]

So my subwoofers are/was wired down to 1 ohm the impedance rose to 3 ohms (witch to me I feel shouldn't be that high) could it be from a stock alternator. The lights don't dim or anything but I feel like i shouldn't be getting a 2 ohm rise. My car is a 2012 Nissan altima 3.5, the amp I'm using is a sundown SIA 3500D, the subs are sundown Uv2 12s.

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[deadrx7conv 10+ year member]

How are you actively measuring impedance?

 

[Mr FaceCaser]

How are you actively measuring impedance?

Multi took, and clamp multi tool

 

[Mr FaceCaser]

How are you actively measuring impedance?

i followed the video to test my output and impedance

 

[Brandon Ivie]

From my experience and from observing results of other builds, you're seeing a normal amount. It's usually a multiple of 2x to 4x the nominal load. Not necessarily +2 ohms or +4 ohms etc.. but a multiple of the nominal load. For example, if you're wired to 1 ohm and rising to 3, that's 3x the nominal load. If you were to rewire to 4 ohms you would likely see the same multiple of 3x which would put you at 12 ohms. And if you were at 0.5 ohms nominal you would see 1.5 ohms. Your system has a rise of 3x which is very normal. I personally had a DD M2 wired to 1 ohm and was rising to 2.66 which means a 2.66x amount of rise. Others have very similar results, some higher, so consider yourself lucky I guess.

 

[Mr FaceCaser]

From my experience and from observing results of other builds, you're seeing a normal amount. It's usually a multiple of 2x to 4x the nominal load. Not necessarily +2 ohms or +4 ohms etc.. but a multiple of the nominal load. For example, if you're wired to 1 ohm and rising to 3, that's 3x the nominal load. If you were to rewire to 4 ohms you would likely see the same multiple of 3x which would put you at 12 ohms. And if you were at 0.5 ohms nominal you would see 1.5 ohms. Your system has a rise of 3x which is very normal. I personally had a DD M2 wired to 1 ohm and was rising to 2.66 which means a 2.66x amount of rise. Others have very similar results, some higher, so consider yourself lucky I guess.

Okay that makes alot of sense

 

[shredder1 10+ year member]

Not to rain on anyone's output wishes, 2 U-12 in recommended usually model up where I'd be liking results between 5-8k input @ 1 ohm. Badazz subs but you gotta power em big for real results.

 

[Mr FaceCaser]

Not to rain on anyone's output wishes, 2 U-12 in recommended usually model up where I'd be liking results between 5-8k input @ 1 ohm. Badazz subs but you gotta power em big for real results.

Ok bet. Now would 8k destroy the subwoofers or should I be fine with 8k

 

[shredder1 10+ year member]

Ok bet. Now would 8k destroy the subwoofers or should I be fine with 8k

Quick reply indeed... Lol.
Throw an 8k on there without understanding limits and you'll clip em to death every time.
My thinking is big power yes but get used to the system slowly. Make sure everything is on point then with a peeled weather eye go for it.

Ive reconed so many subs needlessly because full send... Lol
At those levels it's fun and expensive.
I love those wipers slappin

 

[Mr FaceCaser]

Quick reply indeed... Lol.
Throw an 8k on there without understanding limits and you'll clip em to death every time.
My thinking is big power yes but get used to the system slowly. Make sure everything is on point then with a peeled weather eye go for it.

Ive reconed so many subs needlessly because full send... Lol
At those levels it's fun and expensive.
I love those wipers slappin

Man I'm getting another alternator at the beginning of November most likely 400 amp then obviously big 3 needs to be done (i started hooking the system up myself but the audio shop installed alot and didn't do big 3 to cheap out) then I'll get am amp. I know how to tune using a multi meter but I wanna make sure I know enough to tune before I do it

 

[shredder1 10+ year member]

Man I'm getting another alternator at the beginning of November most likely 400 amp then obviously big 3 needs to be done (i started hooking the system up myself but the audio shop installed alot and didn't do big 3 to cheap out) then I'll get am amp. I know how to tune using a multi meter but I wanna make sure I know enough to tune before I do it

Users still talking about the big 3 and planning 8k just sends dread vibes my way.

Cover all bases up front is best advice

 

[Mr FaceCaser]

Users still talking about the big 3 and planning 8k just sends dread vibes my way.

Cover all bases up front is best advice

Of course 100% I'm doing a high output alternator/big 3 in November!!! Then sometime December or January I might be able to get a bigger amp

 

[shredder1 10+ year member]

I'd consider a dual output alt lug and many heavy gauge grounds throughout. Alt case to batt, engine to batt, engine to frame, alt case to frame and frame to batt. Big 3?.. haha. Then rinse and repeat in back where the amps are. Wire always ate my wallet up but cost less than the alternative. 2 runs everywhere min, sometimes 3 and 4 from the rear (main) battery to amp, 4 from the rear battery to frame. This was for 3K clamped on a single sub. And with a 250a alt why maximize current flow? The results spoke volumes.

 

[Mr FaceCaser]

I'd consider a dual output alt lug and many heavy gauge grounds throughout. Alt case to batt, engine to batt, engine to frame, alt case to frame and frame to batt. Big 3?.. haha. Then rinse and repeat in back where the amps are. Wire always ate my wallet up but cost less than the alternative. 2 runs everywhere min, sometimes 3 and 4 from the rear (main) battery to amp, 4 from the rear battery to frame. This was for 3K clamped on a single sub. And with a 250a alt why maximize current flow? The results spoke volumes.

So i have a 2nd battery in the back running my amps. What is found wierd is they ran the 2nd battery to the main battery instead of the alternator (0 gauge wiring). Now with that said. The 2nd battery does have its own ground (not the best i gotta move it) but it does. So should I run the 2nd battery to the alternator instead or just run off the main battery (obviously with the big 3).

 

[Mr FaceCaser]

I'd consider a dual output alt lug and many heavy gauge grounds throughout. Alt case to batt, engine to batt, engine to frame, alt case to frame and frame to batt. Big 3?.. haha. Then rinse and repeat in back where the amps are. Wire always ate my wallet up but cost less than the alternative. 2 runs everywhere min, sometimes 3 and 4 from the rear (main) battery to amp, 4 from the rear battery to frame. This was for 3K clamped on a single sub. And with a 250a alt why maximize current flow? The results spoke volumes.

Do I need to run multiple postives or just grounds. Here's what I got so far please lmk if I'm wrong. The amps are wired to the wmd battery so right now I have ground and postive on both amps to the battery then 2nd battery postive to main battery postive and 2nd battery to frame. Where do I need to upgrade the rear