audioman2007 wrote:
Several things could have happened. First you need to listen to where the whine is coming from. Is it coming from the speakers, subs, or what? Then after knowing where the sound is coming from, then you go and check the amps ground. For instance if the sound is coming from the speakers ONLY, then simply check that amps ground. Also, check those RCA's. Same goes for if the subs are making that sound. If both are making the sound, then check both amps grounds PLUS check the headunits ground. It is very possible that one of the grounds worked loose and isnt making a solid ground now causing the sound. Oh yea, the sound you are hearing is called a ground loop. Its caused when a certain grounding point has too high of a resistence which causes the alt noise to carry into the ground to the amp. Also check the location of the RCA's in comparision to the power wire. Never run both along the same side of the vehicle. The power wire being so big in gauge will cause the alt noise to transfer from it to the RCA's. I always run my power wires down the driver side and the RCA's down the passenger side. Another thing that could be the problem is the upgraded alt. You might have had a ground loop problem before but was small to where you couldnt hear it. Between the big power wire and the bigger alt, you could have magnified it to where you can now hear it. But I would first listen to where the noise is coming from. If its coming from the 4 channel amp but only the front or back, then its those RCA's not the ground thats causing the problem. Also you can use a DMM to check the resistence on each grounding point. Those readings for each should not be anymore than 1/2 ohm. If one or more are, then theres the problem and you need to find a new grounding point for that wire. If after you have done all this you STILL have the problem, then they do make ground loop isolators. They are basically band aids which go in line with your RCA's and filter out the noise so you cant hear it. I have those on 1 of my amps because I just cant seem to fix the problem. They work great but are only to be used if you have no other choice. Hope this helps.
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I def appreciate the reply, and here's a bit more info, just to further explain. The upgraded alt, and kinetic haven't been installed as of yet, we are still awaiting the delivery on those to get them in. As far as the ground loop, yeah I know the terminology of what I'm looking for was a little off, alt whine vs. ground loop, but I def understand as I went to school down in daytona for mobile electronics, where they def schooled me on terminology, and a vast array of other in depth knowledge. Thats why I wanted to present this question to people that have more experience than myself at actually troubleshooting than I do. The 1/0 gauge is routed solely down the drivers side, RCA's on the pass. Made every effort possible for those not to even come close to crossing paths, as for the ground, both amps share the same grounding point as it goes from the ground (start washer included)to the cap, dist, to amps. I'll still probe the shared ground with a dmm, just to see what the reading says, and hope that isn't the problem, as it is located directly under the box. The h/u ground is still possible, along with the RCA's, as the owner admitted to pulling the h/u out to fiddle with another part of the dash.
Update, while checking the RCA's, even though it only quieted part of it down, once I unplugged the RCA's from the amps front input, the noise subsided to about half the tone. Nothing more with any other set, but at least partial. Also, after I turned the stereo up over the half way mark, there was almost like a distant popping sound that came through the f/r speakers only.
I guess bad back or not, I have to see what I can do. Again, I appreciate the help, any other input, feel free to post it up, otherwise I'll post up what the prob was after the find/fix