# Why ground nearby to the amplifier?



## routevegetable (7 mo ago)

Hey all, am new to all of this but reasonably versed in basic electronics/electrical stuff.

There is a lot of advice saying you should ground your amplifier as close to the amplifier as possible - with as short-as-possible wire.
I'm not saying this is wrong, but I don't understand why doing this would be a good thing.

Intuitively, I would want to ground my amplifier as close as possible to wherever the head unit/source-of-signal is grounded, to minimize the potential for ground loops - I want a very low resistance path between my amplifier's ground and my head unit's ground.

Even if my amp was in the trunk, and I had to run the ground all the way back up to wherever the head unit is grounded and attach to there, it seems that would be better than grounding through a stretch of car body of surely small, but unknown resistance; def no expert here, but would it perhaps introduce potential for EMI too?

Why does grounding close to the amp help?

Sorry if this is asked a lot - it seems like it would be, but I searched around and couldn't find anything.

Thanks
L


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## Speedhunter (Feb 21, 2020)

Each wire size has its max current rating which diminsh by the added lenght. This is why they recomend as short as posible for ground wire.
Chasis of the car is the biggest conductor you have to connect amplifier ground to the battery ground. There is a point where is necessery to run the ground wire all the way to the battery terminal, but leave that to guys who run 10kW+ amplifiers.


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## ckirocz28 (Nov 29, 2017)

routevegetable said:


> Hey all, am new to all of this but reasonably versed in basic electronics/electrical stuff.
> 
> There is a lot of advice saying you should ground your amplifier as close to the amplifier as possible - with as short-as-possible wire.
> I'm not saying this is wrong, but I don't understand why doing this would be a good thing.
> ...


Big wire is cheaper if it's shorter, also, the body/frame of the car will carry more current than you'll ever run through it. You want them grounded to the same place as your head unit, run a small ground wire from the head unit to the amplifier ground location.
That seems like a bit of a smartass response but I really don't mean it that way. 

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## routevegetable (7 mo ago)

Ah k, sounds like it really is just about the reduced copper cost. Which makes sense - sh*t's expensive! Stuff I was reading seemed to be suggesting it's about noise immunity, and I didn't understand how.

Thanks for the responses!
L


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## miniSQ (Aug 4, 2009)

i had a flashback to the 90's.


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## bnae38 (Oct 3, 2015)

miniSQ said:


> i had a flashback to the 90's.


A good time for music.


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## ckirocz28 (Nov 29, 2017)

routevegetable said:


> Ah k, sounds like it really is just about the reduced copper cost. Which makes sense - sh*t's expensive! Stuff I was reading seemed to be suggesting it's about noise immunity, and I didn't understand how.
> 
> Thanks for the responses!
> L


Yeah, it's cheaper and easier to run a small head unit ground than it is to run multiple large amp grounds.

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