[The Ruler]

hi, a buddy of mine just installed some car-hifi in his
2.3i prelude, it's all quallity stuff, but he is getting
this noise over the speakers when he is reving the
engine. It's kinda like the sound u get from a turbo
but it's over the speakers. We already grounded
evrything like the engine,headunit,amp. and an extra
ground lead from the alternator to the negative battery
terminal. all other connections are fine too.
Still the noise doesn't go away. at low volumes
it's really irritating. How can he kill the distortion, what
other things need to be grounded?

thanks,

Roel

 

[GSteg]

how long is the ground cable on the amp?

 

[The Ruler]

it's almost 5 meters. say 4.7

 

[Team Zzyzx]

Happened to me. What you should tell him to do is, since the ground wire is so long (does it connect to the battery?) If it does, use a distrib. block and have one end grounded to the car near the amps and still going to the battery. ALSO it could be a "BAD" ground inside on of the components or "BAD'' RCA cables. Those can pick up some noise if they arent good.

 

[The Ruler]

well, all cables + and - and remote and RCA run through the
center of the car to the back. the ground cable is connected
directly to the negative battery terminal. So should I ground from there to the distib too? By the way the RCA cable are EMI shielded
and twisted if that says anything? they were 30 dollars for
5 meter

thanks

 

[GSteg]

whoa!! 5 meter for the ground on your amp? no wonder..lol...get it about 6 inches and ground it to the chassis. make sure you sandpaper the area so it will get better contact with the metal.

 

[The Ruler]

hey thanks!, were gonna try that.
but another question we did get 16mm2 < the "2" has te be small
of thickness. I learned from school that a thicker cable
has less Ohms resistance. So it's still too long then?
anyways, We are gonna bolt it up to the chassis as well
and see what that does.

thanks for the help

 

[dmny77]

you said that the rca and power cable is runin together. if the other stuff dont work separate the rca from the power cable by like a foot.

 

[The Ruler]

Ok, I will try that too. I can also get some EMI shielding tape
from my work. Will that do any good cuz it's quite pricey?

thanks

 

[k67p67]

Recommend you shorten the length of the ground cable. Power and ground cable gauges should be the same. Also, if you are running components in the front, try changing the location of the crossover as the inductors are susceptible to picking up alternator whine.

 

[The Ruler]

Ok, we're gonna shorten the length of the cable's
run the RCA cable apart from the power cables
and get some EMI shielding if neccesery.
that should do it.

thanks everybody.