Ground Loop Issues

[tyusha]

So i waited with this issue and tried troubleshooting myself.....

But here is the deal. I recently istalled a clarion 4 channel amp, adding it to the factory head unit. Before this amp i had a simple 2 channel amp feeding 2 rear speakers, and had no ground issues, or so i thought anyway.
However now with this new amp i tapped into all 4 channels in order to feed all the speakers. As soon as everything was complete and i trned the power on, i immidiately heard alternator wining THROUGH MY FRONT SPEAKERS. So at first i blamed it on a bad scoche LOC. However with a simple test of unplugging both front channel RCA cables the wine was still there. After unplugging all of the channels (today) and removing the LOC completely the wine was gone. So i felt kind of releaved, but not for long as the wine came back as soon as both RCA cables were plugged into my now new deck (clarion DB345MP) which has 2 sets of pre amp outputs. Although an improvement in over all sound was def. there, the wine was still there also. This makes me think that this should definately be the amp that has grounding issues...
some info:

1)I pulled new wires to every single speaker, they are nothing spectacular but much better that factory wires, this also allowed for a cleaner (as i thought connection)
2)I have components in front, so the wire i pulled through is the input for the crosover. The crosovers currently reside in front door pockets and all the wires go through a hole in the door pannels.
3)The amp is installed under the front passenger seat. All the speaker leads are routed under the carpet. The amp's ground lead is attached to the center tunnel, where the plastic center console gets attached to the bracket
on the right side of the tunnel (i believe).
4)I used Stinger wire terminals and a good quality ratcheting crimper on all of the connections that i made.
5) Most of wires (all speaker wires both RCA wires and the power wire) are in excess (too long) so they are zip tied into neet circles that reside by the amp.
6) Both of my KnuKonceptz RCA cables run side by side under the carpet on the right side of the center tunnel to the center of the dash.
7)The speaker wire leads near the stereo harness are cut where i tapped for the LOC and capped with end caps on all the ends (inside the door as well) The only original car wires attached to the new head unit via factory harness + Metra harness are the 12v, memory wire and ground wire. All connections there were made using gold plated butt connectors.

This just about describes my set up. I am puzzled with this ground loop issue as i don't know what could be causing it. From what i understand the whine is comming only from the front speakers, and with the RCA wires unplugged from the stereo, the front tweeters hiss lightly.

I would really appreciate any input at all. Sorry for my apparent noobness and for the ridiculously long post. I look forward to getting this problem resolved.

 

[tyusha]

Wow, no suggestions?

 

[tyusha]

Bump

 

[DrummerJim50]

would help ya but I dunno about that stuff. free bump though!

 

[tyusha]

thanks and bump again

 

[toucci]

have you upgraded your alternator wire? I have upgraded the ground wires, alternator wire, and fuse box wire and haven't noticed any more alternator whine (I used to get a bit, not too bad)

 

[Poseur]

Is your ground scraped down to bare metal? if you've got noise with no rca's connected, that's more or less your only solution. also, I'd try different grounding locations. I've had different amps that liek to be grounded in different places in the car. there's no real rhyme or reason, no right answer, you just have to sorta be willing to play with it a bit. My current grounding is now back to the center console rear-mount wher eit attaches to the "tunnel" but that's nto to say it's ideal for your car. The ground-wire upgrade is a sound suggestion for many reasons, but won't necessarily solve your problem (though it might) hate to sound vague, but ground loops are a strange thing.

 

[tyusha]

Is your ground scraped down to bare metal? if you've got noise with no rca's connected, that's more or less your only solution. also, I'd try different grounding locations. I've had different amps that liek to be grounded in different places in the car. there's no real rhyme or reason, no right answer, you just have to sorta be willing to play with it a bit. My current grounding is now back to the center console rear-mount wher eit attaches to the "tunnel" but that's nto to say it's ideal for your car. The ground-wire upgrade is a sound suggestion for many reasons, but won't necessarily solve your problem (though it might) hate to sound vague, but ground loops are a strange thing.

Thanks poseur for the suggestion (and for how to pull wires )

Yeah, i am just wondering whether the "mess" of wires could be causing it.... Or maybe some other stuff.... There was not whine at all when the both of the RCA cables were unplugged though.... So i am not sure about that eather.... I am just not sure anymore, you know..... oh well if you can think of any other stuff, please let me know....

 

[Poseur]

oh, simple solution there is to try stringing a pair of rca's directly form your hu to your amp over-seat and all. if that takes care of the problem, then you're good. if it doesn't perhaps re-grounding your deck to your chassis somewhere. Also, if you've got metal-ended rca's tape them off or something, sometimes metal-ended rca's hitting eachother or grounding or anything else is a big cause for noise.

 

[DrummerJim50]

have you upgraded your alternator wire? I have upgraded the ground wires, alternator wire, and fuse box wire and haven't noticed any more alternator whine (I used to get a bit, not too bad)

Where do you get these wires and how much do they cost?

 

[tyusha]

OK. So i did some more tweeking, which revealed that the rear speakers are actually the ones to wine more.... With them unplugged the wine is less.... I took the front speaker RCA cable out from under the carpet and just temporary ran it on the left side of the tunnel just on top of everything.... The sound is a little better. The rear speakers are completely unplugged now.... There is still a bit of a whine left in front. Now i think one other problem that i might be having is the remote turn on wire which is integrated into the rear RCA cable.... Maybe it is the one causing interferance.... I don't know.... Maybe it's just all things put together.... But Pose, what do you think of the remote turn on wire being a b****? Could it be causing this? Should i just run a separate remote wire? What do you guys think? Tnaks a bunch...

 

[Poseur]

REmote turn on carries SOOO little current that it's very doubtful that it is a problem. I'd really look into moving your grounding location, that seems like it's the most likely culprit at the moment.

Thatsaid, running a seperate wire wouldn't hurt, but again, it's such a small amount of current flowing through there it shouldn't matter.

 

[toucci]

Where do you get these wires and how much do they cost?

I used 4 gauge with gold connectors from www.knukonceptz.com

 

[tyusha]

Huh... too little current... OH well Regrounding it is.... Do you think grounding point could be causing just the overall speaker hum and not the whine?

 

[1sty]

If you can, you can come up this weekend and I'll help you figure that one out.

From the sound of it, you have a large coil of power and ground wire right near the ampif not on it? This needs to be cut to length. That wire is creating a major electrical field that could be part of your problem. Also, be sure that the RCA's are no where near the power wire and where they cross, cross them at 90% anlges.The remote wire will have no effect here.

Another thing to consider is that the ground wire needs to be on the floor metal, I couldn't tell if it was on the bracket or not.

If you disconnect the RCA's from the LOC, does the noise stops?
What happens if you only disconnect the RCAs at the amp?

 

[tyusha]

Hey firsty thanks for the generous offer to help me... I'll keep it in mind : ) But honestly i would kind of be ashamed to to even show my set up to the sound god of the forum : ) It's my first honest attempt to do car stereo, without anyone teaching me how to do this stuff... So it's a mess....
You are right about there being circles of wires near around the amp, they are sort of neat though.... But yeah the rca might be touching the power wire at some angles as well as they might be touching speaker wires under the carpet. There is no LOC anymore, as i got a new headunit with 2 sets of RCA's If I Unplug the RCA's no matter from where there is no whine at all, however as soon as the amp powers up there is constant hiss which is not as bad as whine but still quite unplesant... and indicates that there is still someting wrong..... I don't know.....

 

[tyusha]

another thing i really need to do is to put some resistors in line going towards the tweeters as they are killing my ears.... My friend said that he put 10ohm resisters and it helped him a lot... So we shall see... What do you think of that firsty....
Oh by the way i know my tweets are not in the best spot possiblle (sail pannel) but i really am not up for making more holes in the doors....
Oh also front doors soon to be dinamatted as with the added base the rattles are just unbearable....

 

[1sty]

Hey firsty thanks for the generous offer to help me... I'll keep it in mind : ) But honestly i would kind of be ashamed to to even show my set up to the sound god of the forum : )

Don't worry about that, my trunks a damn mess too. No one that really likes to installs ever has a nice setup because the day they finish is the day they start all over again.

Its not the RCAs touching the power Wire I am concerned with. Its the massive field that the power wire will be pumping out and interfearing with the RCAs even if they are a foot away, not to mention interfearing with the amplifiers internal circuits. Its just a long shot to rule out.

IF the amp powers up with no RCAs hooked up to it, is there a hiss?
I am stating to think the amp is the problem. Come on up and we can swap in either my alpine 4 channel or JL 300/4 and we'll see what happens. We can also plug in some muting plugs and see if the amp still has an issue.

 

[1sty]

another thing i really need to do is to put some resistors in line going towards the tweeters as they are killing my ears.... My friend said that he put 10ohm resisters and it helped him a lot... So we shall see... What do you think of that firsty....
Oh by the way i know my tweets are not in the best spot possiblle (sail pannel) but i really am not up for making more holes in the doors....
Oh also front doors soon to be dinamatted as with the added base the rattles are just unbearable....

Are they the stock tweeters or part of a component set?

 

[tyusha]

They are the are a part of the component set. I doubt the amp is a problem since i had hissing with the other amp as well. I think it's the mess of wires that is creating this problem mostly.... but what do i know..... I might be wrong.... I believe if the amp powers with no RCA's there is still some hiss. But then again as far as i remember there was some hiss from front tweets with no amp powering them.... Oh it's a mess....
thanks again for the offer. I might take you up on it. What day is better for you this weekend?