ground issues
Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=86630
Printed Date: May 05, 2024 at 7:27 PM
Topic: ground issues
Posted By: absolute_honda
Subject: ground issues
Date Posted: December 04, 2006 at 1:28 PM
Ok so I have 2 amps, a alpine 4 channel running front and rear, and a bazooka mono amp running (1) sub. I have 3 seperate rca sets running to the back of my eclipse. The 4 channel amp will not come on unless the sub amp is also grounded and also have the rca's plugged in. the power wire is on a distrubution block and the ground is at the same point but (2) seperate wires grounded at the same point. It seems as though the rca's for the sub amp are grounding some how. I can unground the sub amp and pull the rca's from it and touch the outer part of the rca to the 4 channel amp and the amp will come on and work. This started when everything was moved around and the amps mounted on the box instead of sitting in the floor. also since moved i have a horrible whine noise. what is the problem? David Edmundson 757-288-0045
Replies:
Posted By: DYohn
Date Posted: December 04, 2006 at 1:59 PM
Sounds like your Bazooka amp is defective with a bad ground plane inside. Grounding through the RCAs is a bad thing indeed. It also sounds like it was grounding through the case in your previous mounting arrangement. Try running a ground lead to the amplifier case as a temporary solution, but ultimately you need to upgrade to a better quality amp. ------------- Support the12volt.com
Posted By: absolute_honda
Date Posted: December 04, 2006 at 2:07 PM
i thought that might be the issue but it wasnt i grounded the shielding of the rca's on the 4 channel amp and it now works fine but still has horrible alternator whine. the bazooka amp will run fine with no whine all by itself. but why would there be noise now and no noise before?
Posted By: jeffchilcott
Date Posted: December 04, 2006 at 2:34 PM
sounds like power may have possibly been fed back into the head unit, see if you can hook up another source to the 4 channel, mp3 player, another cd player, something besides what you have now, and see if you still have noise.
Seeing as how you have already grounded the shields on the 4 channel it shows that its not just as simple as an unballanced signal from the deck, sounds like a bad signal in general.
You could also try removing the deck from the dash and moving rca's as far from any power wire including the ones from the deck and see if that ight solve the problem.
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Posted By: absolute_honda
Date Posted: December 04, 2006 at 4:41 PM
no noise when i disconnected the rca's from the amp. tried regrounding the HU to the battery still got noise and then tried to the amp's ground location and still noise......... its the same car... just started for no reason
Posted By: jeffchilcott
Date Posted: December 04, 2006 at 4:44 PM
sounds like something might be wrong with the preout's ont he deck then. You have tried grounding the outter shield of the rca's? try also grounding them to the chasis of the radio and then grounding that to a good solid ground source
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2009 0-1000 Trunk WR 154.0DB 2009 1001+ Trunk WR
2007 USACI World Champion
2007 World Record
2006 USACI Finals 2nd Place
Posted By: absolute_honda
Date Posted: December 05, 2006 at 1:17 AM
yeah i grounded the shielding to the amp ground location and then the amp works but still have the noise. I can't seem to figure out where the noise is coming from. It sounds excellent unless the car is running.?.?.?
Posted By: DYohn
Date Posted: December 05, 2006 at 10:11 AM
absolute_honda wrote:
yeah i grounded the shielding to the amp ground location and then the amp works but still have the noise. I can't seem to figure out where the noise is coming from. It sounds excellent unless the car is running.?.?.?
This is a ground loop caused by one of the components in the audio chain being poorly grounded and/or defective. Reading back through this thread I agree it sounds like the internal ground plane in your HU is defective, although it could still be one of the amps or their ground connections. Read the grounding stickies and check all your ground return resistances and fix any high readings. Then try a dedicated ground for your HU. If this does not work something is fried and it's time to start removing and swapping gear. Start with the HU. ------------- Support the12volt.com
Posted By: absolute_honda
Date Posted: December 05, 2006 at 4:21 PM
i tired multiple grounding locations for the HU. the HU is only like 3 weeks old. and this only started to happen after moving the amps around
Posted By: electrostatic
Date Posted: December 05, 2006 at 4:49 PM
does the whine get worse when you separate the rca's? and if you disconnect any of the rca's to that 4 channel amp does the noise go away?
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Posted By: absolute_honda
Date Posted: December 05, 2006 at 11:23 PM
no the noise stays the same either way
Posted By: prodigal
Date Posted: December 06, 2006 at 12:50 AM
Just thinking could it be the size of ground wires cause if the grounds for the amps are too small it could also induce this whining noise
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Prodigal Son
Posted By: absolute_honda
Date Posted: December 06, 2006 at 4:48 PM
i am using 8ga grounds for both amps and they are quite small amps, and it just started for no reason. when i moved the amps the ground location and wire stayed the same
Posted By: prodigal
Date Posted: December 06, 2006 at 7:58 PM
i read your original thread again and i remember i had a similar problem when installing a crossover. It turned out that i screwed the crossover onto the metal part of the vehicle and the noise was terrble with very little audio output. I had to bolt the crossover onto an insulator to prevent direct contact with the vehicle chasis and everything went back to perfect. Try it out.
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Prodigal Son
Posted By: absolute_honda
Date Posted: December 07, 2006 at 11:09 AM
the amps are screwed into the speaker box
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