rca static only when i use 4 channels

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=125032
Printed Date: May 12, 2025 at 11:37 AM

Topic: rca static only when i use 4 channels

Posted By: dr_sinist3r
Subject: rca static only when i use 4 channels
Date Posted: December 14, 2010 at 3:35 AM

hey guys

im running an alpine HU with DEGO components both front and rear powered by a VDO amp. i have a sub aswell but theres no issue with that section of the system.

heres my problem. when i first installed the system i had quite an annoying static noise soo today i decided to try i isolate the problem.

ive followed all the guide ie moving the ground around and everything.

what ive concluded soo far is that if i run only 2 channels ie only the front speakers i dont get any static, ive swaped different rca's and ive tried running only the rears and its the same. As long as i run 2 channels theres no noise. once i run the full 4 channels i get annoying static.

this is the first time ive ever come across a problem like this.

any advice would be very helpful

thanks

Replies:

Posted By: DYohn
Date Posted: December 15, 2010 at 11:39 AM

What do you mean by "static"? Are you hearing alternator whine - does the sound change with the engine RPM? Does it go away if the engine is off? Or are you hearing static-like noise coming from the speakers that is the same no matter if the engine is on or off?

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Posted By: dr_sinist3r
Date Posted: December 15, 2010 at 6:33 PM

hey its not alternator whining. its more of a light hiss. just very annoying when theres no volume and the windows are up.

soo far

ive ran channel 1 and 2 individually with no static.
3 and 4 individually with no static
ive used a splitter from channel 1 and 2 from the HU to open 4 channels on the amp and there was no static

I only get static when i use 4 channels from the HU to the amp

soo i reckon it must be a HU problem. the aircon is right behind the HU but i dont think its that because when i run RCA's on the outside of the car and the HU its not in place i still get static.

Posted By: i am an idiot
Date Posted: December 15, 2010 at 10:08 PM

If you turn all of the gain controls all the way down, does the noise go away?

Posted By: dr_sinist3r
Date Posted: December 16, 2010 at 4:48 PM

yup it does.

Posted By: i am an idiot
Date Posted: December 16, 2010 at 4:59 PM

Turn the gain up till you hear the noise again, then back it off a bit.

Posted By: mrm1776
Date Posted: December 19, 2010 at 12:47 AM

i am an idiot wrote:

Turn the gain up till you hear the noise again, then back it off a bit.

Yup... This... I had the same problem with my 4 channel. You might need to either step up to a larger 4 channel if you're not happy with the volume settings with the gain being lower... or you'll need to get a head-unit with higher voltage pre-outs to help control that noise floor.

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