I have a slight alternator noise problem in my system. The volume has to be turned almost all the way down before you hear it, but I still don't like it.

I have both amps using 8 gauge ground wires going to a distribution block to a 4 gauge ground wire. I am using a strut tower bolt as the ground point. Does any of this sound like it might be the cause of my noise? Can using a distribution block for your ground cause alternator whine in the system? Is my ground location ok?

I spent alot of time putting this system together and I am getting tired of messing with it. If somebody has a suggestion that will save me some time in getting rid of this noise, I would appreciate it.

 

Make sure that your ground is touching bare metal, sand all the paint of in the spot the bolt is on, and i would move the actual grounding spot closer to the amps, it can also be cuased buy cheap patch cables.

 

That ground location is the closest I could find to where my amps are mounted (on mdf board attached to the back seat). I didn't spend too much time sanding the spot under the bolt but I did it good enough, I thought.

Anybody else chime in please.

 

plus check ur RCA's...


btw...what size is your power wire( i presume that it's 4ga)

 

I have 4 ga. power wire too.

I thought my cheap y-splitters for my 4 channel amp might have been the problem. I got some good streetwires y cables and it didn't help. My regular RCAs came with the 4 gauge kit. They are twisted with gold ends, but I don't know much more about them.

Here is a link to the kit I used. It shows a pic of the RCAs.
http://www.rockfordfosgate.com/ezcom...e.asp?key=1558

But I think alternator noise is more often caused by ground issues.

 

in most cases...yes over 90% is caused by bad ground....but the other 10%01 can be anything from bad RCA's to faulty system components...
for an example....about a week ago we installed a system for this customer that consisted of component set, 6x9's, two mtx subs, equlizer, new HU, 4ch amp, and a mono amp....wehn everything was done we were getting alt noise crazy style so after troubleshooting we repalced the 4ch amp....the noise was cut down in half...the the equlizer was also replaced(helped out a lot)...then we could only hear the whine at very low volumes...after replacing RCA's the noise went away....
like i said it's really hard to say what's causing that noise...bad ground accounts for the most part...but it can also be something else....RCA's amp's etc etc

 

Well I can't get rid of my amp lol. Do you think that the ground d-block can cause it or is that generally a safe way to ground multiple amps?

 

try grounding the amps(in the same location) without the dist block...see what happens

 

Yes try that, but sand that sucker down till its nice and shiny silver

 

I tried sanding the spot down real good last night and separating some of the wires even more than I had before. I still have the noise.
I couldn't get rid of the d-block yet because I didn't have any more 8 gauge ring terminals to use for the seperate grounds. I guess I'll have to get some and try that next.
Is my ground spot on the strut tower bad? I could use the seat belt bolt for a ground but I will have to extend my ground wires about one to two feet to reach it. Im not sure that will solve anything but I'll try that if getting rid of the ground d-block doesn't help.

 

if you unplug one set of rca's to the 4channel amp, does the noise go away?
let me know b/c i had a similar problem

 

The strut tower bolt typically is not a good grounding point...too much friction there. Try a more solid spot. Also eliminate the dist block, your just adding more resistance going through it.

--Don

 

Where would you suggest grounding the amps at then if the strut tower bolt is no good? The only other place I see is the seat belt bolt but I would have to extend the wires two more feet to ground it there. Isn't the ground supposed to be less than 18" or so?

And to answer the question before that, I only have one set of RCAs going to the four channel amp. I split those with y cables to accomodate the four channel imputs. I tried eliminating the y cables and just plugging the rca into the front channels and I still got the noise. I really don't think that the noise has anything to do with my RCAs. I could be wrong but Im betting this is a ground issue. Thanks for your imput though.

 

i had that same problem. i had a sony headunit that only had 1 working set of RCA outputs and i had those split off to 3 amps. i just got a new pioneer headunit with 3 sets of RCA outputs and used RF RCAs and it completely solved my whining problem.

 

Seat bolts are also typically bad as the manufacturer usually loads them up with 'locktite' thus not making a clean ground. Any spot of metal properly grinded/sanded/etc down will work.

You arent by any chance running a Kenwood HU are you? They are notorious for engine noise issues....

--Don

 

I don't think the ground block is your problem. i usually use a ground block and have never had problems. ground that thing right to the frame. sand everything down and clean it with alcohol. if that still doesnt work, whip out the multimeter and make sure its grounded properly. If the ground isn't your prob, the next easyiest solution is your rca cable. try another one or try it without the y cables and see if the noise is there.

 

I have a newer pioneer h/u.
I sanded the hell out of the strut tower last night and it didn't make any difference. I looked for another spot to ground it in the trunk and cannot find one. I really don't want to drill into it without knowing what is on the underside. I'm about to say f**k it and live with the noise. I put so many hours into putting this together and I am really tired of messing with it.
Is it true that a ground loop isolator lowers the sound quality? Maybe I could try that? Or maybe I should just keep the volume above 15% because you can't hear it at that point anyway. What do you guys think about the ground loop isolator?

 

on the contrary don. it is ideal to ground to the same spot (using a distribution block). this helps avoid a voltage potential between seperate grounds which in turn can induce alternator whine into the system.

 

On my way home today I could barely even hear the noise. In fact I have to really try to hear it. I have to turn the system almost all the way down and rev the engine to pick it up.
I have probably burned through a half a tank of gas by keeping the rpms way up listening for this crap lately. It seems like it comes and goes. For now I am going to leave it alone since any other ground points would require a much longer ground wire. If it comes back louder tomorrow I will probably change my mind and stress about it all over again. I hate car audio.

 

I have some new info. that might help you guys diagnose my problem.
When I first start the car in the morning the whine is very noticeable. After I drive and everything warms up for a while the whine seems to almost completely go away. This morning it was very bad because I drove the camry all weekend and my car sat the whole time. By the time I got to work the whine was almost gone. Anybody have any ideas why this is happening?