Did not have a problem before the current stereo mod
Here is the situation I have installed two processors into the system. No part of the new processors, signal converters, or power inverter is toughing ground (body panel).
Using RCA to XLR powered converters to send the signal to the processors and then a XLR to RCA powered converted to change the signal back to RCA so I can send the signal to the AMP (Boston GT-50) All components that require 120VAC are powered by an inverter (sinusoidal).
There is no electrical buzz when the key is in the off position and the processors are turned on.
There is no buzz when the key is in the run position and the car is not running and processors are turned on.
No electrical buzz when car is running and processors are off.
There is only electrical buzz when the car is running and the processors are on. As expected this is the only time one should get electrical noise.

What

 

RCAs are unbalanced and XLRs are balanced....are you running through adapters or transformers? If just an adapter, maybe the ground of the XLR is lifted......

 

Powered transformers with gain controls for each direction of siginal XLR to RCA and RCA to XLR.

I am going to swith out one of the Transformers right now to see if that corrects the problem.

Nope still there!!!

This is what i am using
http://www.sweetwater.com/store/detail/CleanBox/

 

BUMP (BUZZZZZZZ)

 

Hmmm....it uses a "wall wart" for a power supply. Where is that connected?

 

Are you referring to a inverter. If so this is where all of the 110VAC components are getting there power. This inverter is hooked directly to the 1farad Capacitor with a 30amp relay acting as a switch triggered by the remote turn on lead from the head unit.
FYI all of my equipment including the head unit is hooked directly to the capacitor to prevent ground loops from existing.

I did some work last night moving some of the signal(RCA/XLR) wires and power wires both 12vdc and 110vac. Everything I could get my hands around was covered in aluminum foil (low tech) and then raped in electrical tape with the intent to have this foil act like a RF shield.

This seemed to helped as the relative volume of the buzz(1125hz) has been reduced.

Now the buzz is interment.
The buzz is uncorrelated with head lights, turn signals, ac compressor, rpm/alternator, or the underbody neons. Does not change pitch/ pop/ come and go, as the accessories are turned off and on.

I have inverted one of the processors functions (dynamic limiter to compressor)to act like a noise gate.
When the signal from the radio is below a specific threshold/when the volume has been turned down the processor now cuts the entire input signal to preventing the buzz from getting through to the amplifiers/speakers.

As the volume is increased to a point where the buzz has been masked by the audio signal the compressor begins to let the signal pass through the system.

This prevents the problem from becoming audible but does not fix or explain what is causing the problem.

I would rather fix the problem than just use the processors to cover it up.

 

heater fan?

 

Heater Fan?????

Are you talking about the Radiator Fan????

The Buzz is sometimes there despite the radiator fan being on or off. I does not seem to matter what is on or off(accessories) to make the sound come through the speakers.

On the qoute that was a slip on my part

 

just saw this...

let me go back and read up on this a bit. i'll edit or repost in a bit.

 

ok... i've actually seen stuff like this before, but only in stage/theater situations... how are the XLR/RCA boxes grounded? if you were in an all AC situation, i'd tell you to lift the ground or set a ground. given you're mixed into 12 V, i'm not quite so sure...

honestly? using a powered XLR to RCA converter is likely to be your problem imo. why not use a non-powered direct box or battery powered direct box? i can't think of a reason you need the gain controls....
typically, i use boxes similiar to this or this and refuse to use the AC powered stuff. (of course, you'd need like 1 for each channel... )
they even make non-battery versions (which i don't see any of on your site), but i'm not sure what gain level your processors need... they may not provide enough gain, but usually pre-amped stuff is more than adequate if the processors are designed for sound board use.

the 1100 hz hum that doesn't vary w/ any other car gear is pretty likely a a 10x multiple of the inverter bleeding through (*shrug* but it seems highly likely to be inverter related).


you might want to consider this... but be cautious as with me knowing so little about how things are wired or where the AC stuff is seeking its grounds...

can you run a direct ground from the RCA/XLR converter chassis to the inverter ground/chassis? i'm guessing the inverter has a 3 prong connector, and you're using a 2 prong wall AC/DC converter?
you may even try dropping a ground from the chassis of the box to the ground on the car...
but not knowing more details on your wiring, i'm not 100% sure what either of these might do... so be cautious. it should only ground the converter to the same ground as the inverter is using... which should be a chassis ground..
but not knowing how the wiring on the XLR/RCA converter is setup i'm sorta shooting in the dark here...

*hrm*
i'm just not quite sure with all the DC to AC to DC conversion going on here.

what about just wiring up some of your own XLR to RCA adatpers?



if you want, i'll PM you my number. i've simply too many holes in my understanding of your setup to even begin to ask or answer questions. and i'm not even sure i can begin to troubleshoot this remotely...


*edited yet again... i've edited this thing like 2 dozen times... i think this is a final. *