Ground Loop

[Stryker]

I feel bad about just reading your problems . I would be in full on OCD if something like this happened to my system. I read it all and I'm not sure if you've grounded everything to the same spot? Have you? Might be a royal
PITA but try that if you haven't already. Also have you tried eliminating the line driver? I'm thinking you use the one in the EQ tho. When I had noise after my original
install with my RSd amp setup it was from a high end RCA. I switched back to my old Scoshe EFX's and boom, gone . I hope you get to the bottom of this . my guess would be the external LD if thats how you have it setup.
keep us updated.

[ttocs]

I don't see a line driver in the system?

[Stryker]

I don't see a line driver in the system?

prolly using the one in the EQ then.

[ttocs]

is the chassis of the eq grounded at all? Try disconnecting all the connections(signal and power) from the eq and test for continuity to ground. I have found that line drivers do not like to have the chassis gronded and can cause the noise/static problems you described.

[stipud]

Sounds to me like one of your RCA shields is broken, or somewhere along the chain an RCA shield is disconnected on the amplifier/eq.

[ttocs]

also let me ask then how you do the DMM methode with a eq/driver?

I thought you had to calculate the output and then tune the amp to get that, when you mess with the input voltage how to you account for that in the equations to figure out what power you should see?

[dwnrodeo]

This is my third time responding to this because it has effed up twice.

Thank you for all of your input guys, I really appreciate your help. I will try and address all of the questions.

you have tried grounding the outer shiel already right? ]
Have you tried both cleaning and retightening the grounds, and trying to powerthe deck at the same point as the amp/eq? try running two wires to the amp/eq poiwer point for power/ground and see what happens.

We might have gone over this before but I really do not want to read all of it again.

I soldered individual jumpers from each RCA shield on the head unit to the chassis of the head unit itself and it did not alleviate the problem. I also have everything grounded to the batter as shown below. The amps and the head unit are grounded directly to the battery and positive is direct to battery. I swapped out the EQ with an ax204 for the time being and it is powed by the DD5 which is powered directly to battery. All remote amp turn on's and the AX204 remote turn on is controlled by the DD5 which gets its signal from the head unit.

ttocs wrote:
I don't see a line driver in the system?

prolly using the one in the EQ then.

Correct.

is the chassis of the eq grounded at all? Try disconnecting all the connections(signal and power) from the eq and test for continuity to ground. I have found that line drivers do not like to have the chassis gronded and can cause the noise/static problems you described.

It is mounted to plywood, completely isolated from the chassis of the vehicle.

Sounds to me like one of your RCA shields is broken, or somewhere along the chain an RCA shield is disconnected on the amplifier/eq.

I was thinking this is a possibility as well!!!!!!!!!!! I have 4 amps in my system and they are all 10+ years old. How do I check the RCA shields on the amps? Continuity test from RCA shield to amp ground?

also let me ask then how you do the DMM methode with a eq/driver?

I thought you had to calculate the output and then tune the amp to get that, when you mess with the input voltage how to you account for that in the equations to figure out what power you should see?

When I first tuned the system I used an o-scope to set the gains (before this problem). Now it is not tuned at all.

[dwnrodeo]

Also, I know my gain pot on my tweeter amp (XS2300) is VERY dirty and if I try and adjust it I get lots of static as the gain knob moves. I keep it all of the way down and control my gains through the ax204, but I thought this might be worth mentioning as do not know how it affects the signal or signal ground.

[ttocs]

try to tug/pull/manipulate the rca connections on the back of the deck and see if you can get the static to come on. I agree it sounds like an rca problem but I wonder if it isnt't the decks rca output connection.

Have you tried any technical taps on it to see if you can isloate the static?

[stipud]

Do you have a headphone -> RCA cable? Try hooking up a portable device to your amp, EQ, and up the chain to see if you can spot the noise source that way.

[dwnrodeo]

try to tug/pull/manipulate the rca connections on the back of the deck and see if you can get the static to come on. I agree it sounds like an rca problem but I wonder if it isnt't the decks rca output connection.

Have you tried any technical taps on it to see if you can isloate the static?

I've messed around with moving the RCA's plenty of times with no real luck. No "technical taps" yet. If I have to do that and it works, then I'll have no problem buying a new head unit.

Do you have a headphone -> RCA cable? Try hooking up a portable device to your amp, EQ, and up the chain to see if you can spot the noise source that way.

I do have that cable. I've hooked up my mp3 player to the EQ and the alt whine goes away, but the pops and clicks are still present. Do you recommend unplugging all amps then start one by one? Tweet amp -> EQ then Mid amp -> EQ, etc...?

[stipud]

Do you have a headphone -> RCA cable? Try hooking up a portable device to your amp, EQ, and up the chain to see if you can spot the noise source that way.

I do have that cable. I've hooked up my mp3 player to the EQ and the alt whine goes away, but the pops and clicks are still present. Do you recommend unplugging all amps then start one by one? Tweet amp -> EQ then Mid amp -> EQ, etc...?

Cool... so it sounds like the headunit or the headunit->EQ RCA is the source of the alt whine. Try replacing the RCA that runs between the headunit and the EQ temporarily (just run it over your seats quickly). If it's not the RCA, try grounding the RCA shield to the headunit chassis. If that doesn't help, try moving your headunit ground. You can temporarily connect a long ass wire to the ground and run it back to where your amps ground. Still noise? Headunit is probably FUBAR.

As for the clicks and pops, definitely try connecting at each one of the amps. If it's still present it would be amp issues most likely, or an issue with the amp ground.

[dwnrodeo]

Do you have a headphone -> RCA cable? Try hooking up a portable device to your amp, EQ, and up the chain to see if you can spot the noise source that way.

I do have that cable. I've hooked up my mp3 player to the EQ and the alt whine goes away, but the pops and clicks are still present. Do you recommend unplugging all amps then start one by one? Tweet amp -> EQ then Mid amp -> EQ, etc...?

Cool... so it sounds like the headunit or the headunit->EQ RCA is the source of the alt whine. Try replacing the RCA that runs between the headunit and the EQ temporarily (just run it over your seats quickly). If it's not the RCA, try grounding the RCA shield to the headunit chassis. If that doesn't help, try moving your headunit ground. You can temporarily connect a long ass wire to the ground and run it back to where your amps ground. Still noise? Headunit is probably FUBAR.

As for the clicks and pops, definitely try connecting at each one of the amps. If it's still present it would be amp issues most likely, or an issue with the amp ground.

I did a continuity check on the RCA from head unit to EQ, and it checks out fine. I will replace this evening just to make sure and get back with you guys. If I still have noise, I will run a ground to the - distro block in the back just to make sure. If that doesn't help, I'll buy a new unit from Crutchfield and pray to God that it works.

I can live with pops and clicks temporarily. I just want some music in my vehicle after 2 and a half months without!

[ttocs]

seriously try the taps. Just start with light taps on your finger tips, then move up to your knuckle, then go get a hammer, finally you will need a 15 lb sledge .

Ok forget the hammers but with intermitten static problems it sounds like a bad connection or a short. This is the perfect time to start the taps as if it is you will probably find it pretty quickly as when you tap the bad spot the static will be heard.

Learnen this my first freshman year in college and you would be suprised how often I used it to diagnose a problem.....

[dwnrodeo]

FINALLY!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

The culprit has been identified!
I just ordered a brand new unit from Crutchfield and switched it out. No luck. Same noise. I unplugged the antenna and the noise lessened. I started to assume it was induced noise from a noisy component in the vehicle (ECU, fuel pump, etc...) For some silly reason I looked at the wiring harness to make sure everything was copacetic. Everything looked fine so I decided to start disconnecting the speaker wires in the harness since I wasn't powering any stock speakers anymore. I cut the front speaker wires turned it back on and voila! Success! No pops, clicks, humm, buzzing, etc... When I cut the old speaker wires in the doors, I was certain I properly insulated them so as not to cause a short, but obviously something went awry. I am so fucking stoked that I got this solved! Thank you everyone for your input, advice, and support. Now I can finally put my vehicle back together (after 5 months)!

[stipud]

Well ain't that annoying! Good thing your headunit wasn't damaged at least...

Glad you got it fixed man! Enjoy the tunes!

[dwnrodeo]

Well ain't that annoying! Good thing your headunit wasn't damaged at least...

Glad you got it fixed man! Enjoy the tunes!

I was surprised it wasn't TBH.

[dwnrodeo]

My ground loop came back in early December, but I figured I wouldn't burden you guys with updates that went nowhere. It happened one day out of the blue, I just started the vehicle and there it was, back with a vengeance. After a week or two, it went away again on its own. Two days later, back again. Then my right tweeter started randomly increasing volume until it would distort and cut out completely. It would gradually come back on its own to normal listening volumes then repeat the volume increase and cut out about every 10-15 mins. I figured it was the gain pot that was dirty and sent in my tweeter amp to valeks1 for repair. Sure enough, dirty gain pot and cold solder joint were the issues (this is the second time this amp has gone to PG for repair, first time was previous owner fault). I got the amp installed today and no noise! Until I plugged in my sub amp RCA's then some noise came back. Turns out I had them plugged into the RCA output at the amp. Doh! Fixed that and problem solved! I still can't plug in my antenna and I have the wiring for the headunit plugged into my distro blocks because I still get noise if I have it powered straight from the battery (go figure?), but I don't listen to the radio anyways.

So after new RCA's, new crossover/line driver, new alternator, new headunit, several power wiring options tried, and an amp repair (almost $800) what will I take away from this experience/headache/mind fuckery?... Never again will I install a multi-amp system. From now on it is a single amp setup for me. Too many variables to troubleshoot.

[stipud]

That's some shitty luck right there! But yeah, that's always the main risk about adding extra amps... you also add extra failure points. Not to mention the added current draw and ensuing system complexity. I haven't faced the issues you have but I also got tired of complex setups, so I switched to single amp and haven't looked back!