I just finished my amp rack where my amps are now mounted on wood. i didn't have this problem before and all i meant to do was remount them on this board. so far i have regrounded the head unit [pioneer].didnt work so i put it back. i ran new rca cables thinking that maybe it was an induced noise...no luck the power and remote wires are ran on thedrivers side and the patch cables are on th pass. side. with the head unit pulled out i unplugged the rca's from the unit and it is quiet. if touch the cable with a finger i can hear it again but it is less obvious. there are 2 amps and teh ground is through a dist. block. but it is the same as it was before with no noise. i have went the extra mile and tried regrounding it at least 10 seperate places. 2 preouts...both have this noise PLEASE HELP. IM RUNNING OUT OF OPTIONS.im going to be out of my envelope soon
How long are your grounds from your amps and headunit? I don't think it's the greatest idea to run your grounds through a dist. block. How many volts are your pre-outs on your Head Unit?
hey joe, the ground form the amps are probably 15 to 18 inches with the dist block in between. maybe 6" in front of the block. the block is mounted right in between the amps. after trying 3 seperate head unit grounds unsuccessfully i put the ground on it back to the factory ground. they sounded the same so i figured the factory ground would be the best bet. the head unit is a pioneer deh 4500. i believe it is 2.2 volts
Well, I had something greater in mind. Don't run out of options and you won't have to bother us! Hence DONT LICK THOSE ENVELOPES CLEAN! I'm just kidding bud. Whoo...been a long week...
ok....... i went through the entire system with my walkman as the sourceusing a set of 1/4" to rca plugs i found at radioshack. it is obvious that the problem is the head unit.i've tried regrounding it 3 times and it hasnt worked. does anyone know how i can fix this or whether or not the head unit is defective.maybe there is some way to fix this. thanks in advance for the help
What you need is a ground loop isolater. It will connect inline to your preanp output to your rca jacks. You can find a cheap one that gets that noise out at autozone in there cheap audio section or at a local shop.
i have read that ground loop isolaters significantly reduce sound quality and should only be used when it is absolutely necesary.if this is a myth then i'll go get one tomorrow. is it odd that this sort of seemed to happen overnight,one day it was fine and the next it was ruined. i also read the richard clark autosound 2000 thing on troubleshooting. it stated that a new power source should be ran to the head unit if regrounding doesnt workand if the noise is still present after that either replace the head unit or get the entire electrical system checked. that seems excessive so i hope the isolater works out.thanks.joseph,joe and tb
try the loop isolator. if you think it reduces the quality at all, pull it out. if it fixes the problem then keep it.
you can also try running your own switched and constant +12V lines to the head unit in addition to a direct, short chassis ground wire for the unit as well. the noise may be introduced by the factory harness being near something else inducing the noise. usually caused by the ignition +12 sharing a circuit with your actual ignition box..
i have put in a loop isolator.it seemed to help a little.i ran a new constant and a new ground which also seemed to help. i went back through all of my gains settings and redone them. while i had it out of the dash i tried to put an in line filter in it too. the whine is now low but most definately still there so i have to assume that my hu is nearly shot.am i correct in assuming this. thanks again for all the help.this problem is ridiculous.all in all i think i have done everything i can do.its nearly rewired completely.
If you say this problem only cropped up after building the amp rack I'd go through your system looking for things that have changed. Are your RCA plugs crammed up against anything where they go in the amps and are putting undue stress on the inputs? I had a similar noise problem after installing an active crossover in my center glove box. Turns out one of the RCA plugs was binding against my arm rest support. I relieved the pressure and the noise disappeared.
Oh and my experience with those in-line ground loop isolators/matching transformer dealies has been very poor. They do work but always seem to kill frequency response enough to bug the heck outa me.
If you've got two sets of RCA's running from your headunit(one for mid/highs, one for subs) you could try swapping them out at the amps(and the h/u if necessary) to see if you have a damaged cable. Chances are if this is the case only one(the mid/high) will be fubarred. If you've only got one set coming from the h/u and have a spare RCA cable that'll reach you could try temporarily swapping with that.
Oh nm you said both preouts have noise. Try the RCA swap thing at the amps and see what happens. At what point did you hook up the Walkman? At the h/u or at the amps? If you hooked it up at the h/u and no noise then it may not be your RCA's, but it still could be as the Walkman isn't grounded to your car's chassis.
I just don't see how it could be your h/u as nothing in that vicinity was changed when you installed your amp rack.
i dont understand it either fishy. i never touched anything in the dash when i remounted the ampsunless i inadvertently allowed something to touch something it shouldnt which shorted the head unit. i started at the amps and plugged the walkman directly into the amps.it was noise free so i moved to the huand tried unplugging both sets of rcas and one at a time using couplers tried the walkman through the cables. it was also noise free. when i plug the rcas back into the deck it is whining though.i have rewired the deck and it is still doing it.so my only option it seems is that something shorted the hu. thanks for the input fishy
i had a terrible problem with whine in an older car of mine went thru all the crap you went thru and finally gave up with a little background whine(drive me batty) went out a bought an audiocontrol xover to add to my system unrelated to whine and voila the isolators in the xover cured my problem something to do with unbalanced and balanced inputs for rca try it if you have a bill to spare
i think i may try to round up a three.1. i had a four.1 in a past install and it was absolutely amazing. just bought some new re se12's though so i may have to deal with my whine for a while until the money tree blooms.with a wife and 2 children things arent as forthcoming as they once were. thanks
Hey Jamie I ran across this post and thought of you:
You can induce noise into a system via power wires, but not through the RCA's.
After I installed my amplifier, my car had wierd ignition noise, even after the system was totally powered down and the amplifier removed. Mystified, I put the amp back in and drove around for another week before I complained at Eric Holdaway that I had mystery ignition whine noise in my car and I just couldn't understand. Eric asked me if the power wire ran close to the passive crossovers. I answered "yeah, why?"
Three zipties and one rerouted by 3" power wire and the noise was gone. Apparently the coils in the passives induce noise when placed too close to the power wire. Who'd of thought.
Apparently the power wire/rca/noise thing is a myth(see Richard Clark's post above that one), but if you've rearranged any passive xovers in your reinstall and placed them too close to a power/ground wire that could be the problem.
Thought I'd post here just in case you hadn't got things sorted yet, plus for some strange reason noise problems fascinate me.
