hi guys, i have just installed an amp to power my 6x9s at the back and anyway when the key is turned to the acc position i get clean audio, then when i turn to the on position i get a really high pitched ringing noise through the 6x9s. i dont get noise from the front speakers because they are connected directly to the head unit. then when the engines on i get what i beleive to be alternator whine as i get a high pitched whine that adjusts to the engines rpm. i have tried a inline noise filter but that didnt work (didnt make a change) it only just started happening when i put my amp in. also my ground cable for amp is only 1ft long and is connected to a clean bolt. power and rca are on seperate sides. I just got a new pioneer head unit today and still makes the noise at the on position and when the engine is on. Oh and i tried just connecting the amp to a battery charger and plugged the rca cables into the head unit and i got clean sound even when the engine was on. please help thanks
where exactly is your ground connected to? and is the surface to bare metal? also you may want to try to ground the RCA's at the deck. or try grounding the body of the amp as well... the problem is surely a bad ground
sounds like maybe something might be grounded out on the car itself (maybe) how is the remote wire ran ???
the remote wire is ran along side the power cable to the amp. From head unit, down to floor then ran under carpet till it gets to amp.
that may be your problem. I never liked the seatbelt harness as a ground... you may want change that or sand the part of the chasis (body) down to BARE metal then hook up the ground again.
ok thanks il try move the ground point. Also i used a multimeter to test voltage on the batt, head unit and amp and there was about 0.3v difference between the three if that means anything.
Temporarily run a wire from the neg battery terminal to the ground on the amp....Does the noise go away? I would double check the big 3 and MAKE SURE your battery is grounded very good to the engine AND the chassis of the car....I bet money the noise is from the poor grounding of the amp....I could be wrong....
did that and still noise i connected both negative and positive to battery and amp was away from the car. although i ran a battery charger to the amp and rca's to headunit and no noise. what now? thanks
so you ran it with a battery charger and you didn't get noise? sounds like some sort of ground problem to me.. maybe a chassis ground is messed up or something of that sort, meaning it's with the car and not your gear. you may want to run a new battery ground to chassis then and engine (ground the wire on the body of the alternator) to chassis ground as well all with at least 4ga wires. that should do the trick.
also did a random test today, i put an rca to headphone socket cable into the input on the amp and plugged other end into my ipod and i didnt get any noise.
so how do i re ground everything? i did notice that the cable from negative on battery is looking a little rusty and corroded. so for the new battery wire, do i just put a new lead to where its hooked up to now? and how about grounding alternator?
I have fixed alternator whine by putting a noise filter on the amp line but have to set the gain on the amp to minimum with engine off then with engine on I can turn the gain up to watever without anynoise. After the engine is turned off and on again I get alternator whine and have to turn engine off and reset the gain. What do I do to fix this happening everytime?
putting a noise filter isn't fixing the problem dude. it supresses it, that's all.... like i said before, you'll have to redo some grounds in the engine... 1. ground engine to chassis. 2. ground alternator housing to batt.
so the mesh strap that goes from body to engine needs replacing? and just soldier a wire to body of alternator and run it to negative on battery? and this will solve problem? thanks
What is happening is this.... The amp does not have a strong ground where it is grounded currently...So it is trying to seek a ground back through the connections leading back to the head unit that IS properly grounded... The largest ground wire in the vehicle is the chassis but on each end there has to be sufficient clean path for the chassis to get back to battery negative. The mesh straps are ok when new but they can harvest all kinds of corrosion. What is the best bet is to ground the battery to the chassis and to the engine (theoretically the engine is grounded to the chassis, but corrosion and dirt or looseness can cause a bad ground path) Using a large cable (4 guage or bigger) run from the battery negative to the engine. usually there is a bracket that the negative cable runs to on the engine. Also if you can ground from the battery to the chassis or run a cable from the engine ground spot to the chassis ground spot...Make sure all the mounting surfaces and fasteners are clean or new and tight... Willy
