ground loop

forbidden wrote: Before you jump on the headunit, what about the rest of the system? Are you using amplifiers in this system? Where are they grounded to? Is there a RCA cable that is pinched?

negative... RCAs are good... I am running MC 201XLNs to the back and 101xln from the Electronic Crossover. EC is new and amps work fine.Mark "Hamzter" Cinense

1991 Infiniti G20 w/JDM SR20DE

Eclipse CD8445

MTX Thunder 684

Polk DB6750

Polk DB6500

Optima Red Top in the Trunk

forbidden wrote: My bet is that you have a huge difference in potential between all the amps, the crossover and the head unit. List all of the equipment, model # etc. how they are installed, where they are installed and we can go forth from there. To me this is indicitave of a install related issue or a bad component further down the line. Lots to go over yet before you run out and purchase a new cd player. (try a new Eclipse though and if you still have noise, you know it is not the head unit - the wire harness is the same for all units over the last 6 years or so).

sure... here it goes: Eclipse CD-8445 to Memphis Audio 16-X03 3 way crossover to MTX 684 4 Channel amp powering Polk DB6750s Mids and Tweets MTX Thunder 1500dx powering 1 Infinity Perfect 12.1 1 Farad cap connected to the 1500dx Sir-ECL1 from CD-8445 Headunit. I am using Monster Cable 201xln to the electronic crossover and 101xln from the crossover to the amps respectively. I am not a pro installer, I am a hobbyist as my real job is computers. I get into the electronics part as a hobby because my real job does not allow me to play with electricity. so any help and education is definitely welcome.Mark "Hamzter" Cinense

1991 Infiniti G20 w/JDM SR20DE

Eclipse CD8445

MTX Thunder 684

Polk DB6750

Polk DB6500

Optima Red Top in the Trunk

Ah.  That crossover could be the culprit as it is also a line driver and it is way more likely to be bad than you HU.  Make sure your ground for the HU and the crossover is the same, and make sure you have CAREFULLY gain-matched the HU output to the Xover input and the amps to the Xover outputs.  Indeed, I suggest the next thing you should try is to take that out of your signal path completely and run directly from the HU to your amps and see if it helps.Support the12volt.com

DYohn wrote: Ah. That crossover could be the culprit as it is also a line driver and it is way more likely to be bad than you HU. Make sure your ground for the HU and the crossover is the same, and make sure you have CAREFULLY gain-matched the HU output to the Xover input and the amps to the Xover outputs. Indeed, I suggest the next thing you should try is to take that out of your signal path completely and run directly from the HU to your amps and see if it helps.

Good point and normally I would agree with you since I have not thought that the 8volt output would have made an issue. I am not sure if I can adjust that. I will have to read the op manual. The only thing is that I had a Coustic Electronic crossover before I had replaced it with the Memphis Audio EC. I recall that I had engine noise when I first installed this headunit, but was not sure if it was my battery run to the trunk or my alternator. When I initially installed my HU I did not have any amplifiers installed except the OEM amplifiers were inline as high level inputed from my speaker output. I am wondering if that is somehow the culprit. I removed the rear oem amp and everything is on its own separate run. So anyway I did run a seperate ground from the HU to the spot where the EC is grounded in the trunk. Eclipse TS told me to do that. AAMOF, they told me to run another ground in conjunction with the one I just ran to another location, ie chassis ground close to the HU. that is why my original question is does adding more grounds create a Ground Loop? this has got to be my most challenging install.Mark "Hamzter" Cinense

1991 Infiniti G20 w/JDM SR20DE

Eclipse CD8445

MTX Thunder 684

Polk DB6750

Polk DB6500

Optima Red Top in the Trunk

ok... sorry for not listening to you guys, my RCAs going to the amp from the crossover was the culprit. Not to mention that my Crossover was somehow on top of the flippin' positive cable from the front. about 98% of the noise was coming from this. I will be rearranging my layout. However I am still getting a little alternator noise. All my grounds are dead on potential. Without the car on 12.0v across all grounds With the car on 14.26 across all grounds any suggestions?Mark "Hamzter" Cinense

1991 Infiniti G20 w/JDM SR20DE

Eclipse CD8445

MTX Thunder 684

Polk DB6750

Polk DB6500

Optima Red Top in the Trunk

Eliminate the crossover, chances are you totally do not need it and it more than likely is the source of the noise as I first suspected.Top Secret, I can tell you but then my wife will kill me.

I have never used a ground loop isolator. Do they work? I mean really?Mark "Hamzter" Cinense

1991 Infiniti G20 w/JDM SR20DE

Eclipse CD8445

MTX Thunder 684

Polk DB6750

Polk DB6500

Optima Red Top in the Trunk