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Discussion Starter · #1 ·
So I have noticed that as soon as I add a sub into the mix I am getting suppression all of a sudden… no new amps just bridged 2 channels of my existing 4 channel amp..

So either the additional current draw is affecting the alternator or the battery is getting too old…

Any ideas here


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Discussion Starter · #2 ·
So I bridged 2 channels on my 4 channel amp and now I have suppression I am wondering if this is related to current draw

Either battery or alternator?

Any ideas on this?


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Suppression? Please elaborate...

Voltage, SPL or other?
 

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So bridging raised the noise floor and you're hearing engine whine you didn't have before?

Is the whine only in the sub channel or system wide?

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System…


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That's odd but wouldn't be caused by the battery and wouldn't be caused by the increased electrical demand unless it only happens when the bridged amp is under a heavy load.

More likely you need to clean grounds as the old ground is not up to the task of the increased demand.
 

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Discussion Starter · #10 ·
That's odd but wouldn't be caused by the battery and wouldn't be caused by the increased electrical demand unless it only happens when the bridged amp is under a heavy load.

More likely you need to clean grounds as the old ground is not up to the task of the increased demand.
Hmmm I am using the factory earth point in a BMW - never had issues using that point before in my other car…

I wonder if I am getting some sort of noise from the alternator - maybe I should try a cap and see if I can filter out the noise


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Hmmm I am using the factory earth point in a BMW - never had issues using that point before in my other car…

I wonder if I am getting some sort of noise from the alternator - maybe I should try a cap and see if I can filter out the noise


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Engine whine usually comes from the ignition not the alternator - you can try and eliminate it with a cap but I'd try running a dedicated ground from each amp back to the battery and see if you can get rid of it that way. One of the amps will usually be the culprit and then you can clean the grounds (or upgrade them) to that amp.
 

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Discussion Starter · #12 ·
Engine whine usually comes from the ignition not the alternator - you can try and eliminate it with a cap but I'd try running a dedicated ground from each amp back to the battery and see if you can get rid of it that way. One of the amps will usually be the culprit and then you can clean the grounds (or upgrade them) to that amp.
I hear you… I am so space limited right now the thought of running more wires isn’t as easy as it sounds..


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I hear you… I am so space limited right now the thought of running more wires isn’t as easy as it sounds..


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It's not meant to be a fix - troubleshooting technique to locate problem before throwing other fixes at it that could create future problems.

If you can isolate the point that's picking up the RF noise then you can fix that so it doesn't happen anymore rather than trying to filter it out.

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Discussion Starter · #14 ·
It's not meant to be a fix - troubleshooting technique to locate problem before throwing other fixes at it that could create future problems.

If you can isolate the point that's picking up the RF noise then you can fix that so it doesn't happen anymore rather than trying to filter it out.

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Let me see how it behaves tomorrow when I drive the car and see if it goes away like before if not I’ll have to see if I disconnect the sub if the noise goes away


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That's odd but wouldn't be caused by the battery and wouldn't be caused by the increased electrical demand unless it only happens when the bridged amp is under a heavy load.

More likely you need to clean grounds as the old ground is not up to the task of the increased demand.
I think you hit the nail on the head there, dirty ground can't handle the increased current. And the intermittent improvement is just from vibration temporarily improving contact.
 

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Well engine noise went away after 2mins of driving so I dunno…


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Sounds like a thorough deox and cleaning is in order in your near future.
 
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