Alternator Whine

[Guest Guest_BenW_*]

Someone help me.

Got all the goodies hooked up and there is some alternator whine. I need to know what wire is the ground off of the factory SC-815 HU. Specifically, what color is the HU ground?

Dont worry, the volvo HU is getting canned soon, but for now, i just wanna get the noise out.

Thanks for any help

[Bing_0]

one thing you would want to makes ure when you are using horns is that your system is totally devoid of noise, wtih the 110+ effieicny on those puppies, any alternator noise is going to really show through.

my key to eliminating alternator whine is as follows:

1. use twisted pair RCAs on mid/high amp channels

2. keep the power wire and RCAs running on opposite sides of hte car, try not to cross them at all, if you must, cross them at 90 degree angles

3. keep the ground wire the same size as the power wire and as short as possible and grounded solidly to a study piece of the car, sand whree the grounding point is down to bare metal

after these three stesp are taking, the rest is:

1. make sure you ahve a high quality amplifier, low quality amps are more prone to noise issues

2. high a relatively high output voltage going into the amps (4volts is pretty good), and then you can adjust the gains so most of the noise is filtered out

i have never had a noise filter work well, but if your noise is caled by ground loops, go to radio shack and get a ground loop isolator, they may work well in certain situations...but use it as your last resort, these are other higher quality ground loops isolators around bu the radio shack one has worked fine in the very few times I have used it...

b

[Guest Guest_BenW_*]

I'm now conviced that the noise is coming thru the power wire. Some sort of EMI or RF interference.

1. disconnecting the inputs from the HU and running a thumb test at the amp with a every short RCA gets the same hum (whine).

2. jumping the main power to to the amp remote turn on, so no remote signal from the HU, gets the same hum (whine).

Could this be a battery/alternator/ground issue "in front of the firewall?"

Re: your questions

1. Yes, Stinger Zero Noise

2. not entirely, about 16 or so inches apart. But i already found that even running no input from head unit that amp was still spittin' out that whine.

3. Yes, amps are grounded right at the amp to the body of the car. bare metal, sanded past the paint and undercoat.

after this

1. amps are PPI Powerclass 4400.2 and 2200

2. output voltage is from factory HU so it's probably gobbled up.

I wonder if i run a new ground from alternator if that would help.?.?.?.....

[Bing_0]

go to radioshack, get a 15 dollar ground loops isolator, plug it inline with your rcas going into the amp, see if it helps, if its doesnt, return it, it never hurts to try...

your power wires does not induce noise, only your signal wires (rcas, speaker wires) can induce noise, and out of those two, really the rcas are the only thing prone to noise...

b

[Guest Guest_BenW_*]

Alright.

NOw dont expect a reasonable explanation but i cured my problem. I was a ground problem with the home made RCA adapter from the HU.

Something to do with a third wire that ended up needing to be grounded and it wasnt. NOw it is, and there is no alternator whine and NO hiss.

(note: this will be solved entirely when a new HU is installed but until then, im going with this!)

darn what a sound those horns put out. Even without any eq they sound pretty darn good. real darn good. now im totally jonesing for the sub to be installed.

oh yeah, and the front doors......they rattle....... a little more than id like

oh yeah, and another thing, the door pods have been resurected but another form. they are primed and mounted. just gotta figure out how to run new speaker wire to them without removing the entire dash. any ideas?