hey guys, got noise in a sub/amp install. I got the rcas running down the passenger side, and 12v and remote running the driver's side. Bad noise when the key is on full accessory, okay when just on radio. where should I start?
while the amp is making noise, unplug the rca's. if theres still noise, check your ground. if theres not, make sure the rca's arent pinched or try plugging in one at a time to narrow down which side is faulty (if not both). Make sure the filter on the amp is set to low pass, engine noise will not play on lp unless theres a serious problem with the wiring or amp. other things to look for ; power wire zip-tied near or on sparkplug wires, broken power wire (two ends taped together), bad radio ground, any kind of aftermarket ign coil setup usually causes engine noise. I know this is a lot but unfortunately many things can cause engine noise. This will at least give you a check list to start with. PM me if you still have a problem or if you want me to meet with you to look at it. Good Luck!
thx guys. I'll try teh troubleshootz. (The (cheapy)amp doesn't have a filter, the kenwood HU has its own, and it buzzes on that.)
sadly, unplugging the RCA eliminates the noise. Its a quality twisted cable, sounds fine in home audio gear. Something is emitting the noise. not sure where else to troubleshoot, no aftermarket engine work, power wire is only next to the starter cable really, then runs into the grommett at the pedal, then down the driver's side.
Hope you don't mind me jacking your thread but... MY CAR SOUNDS LIKE A DAMN GARBAGE PAN!! I hate it! I hate it!!! Im running a 1000w kenwood amp w/ 2 10" kenwood subs in my trunk, and it sounds f**king ghetto. Turning my volume up to anything over 12 makes my trunk rattle like crazy...I'm tired of it. I love bass but this is just stupid. 1. Does the Dynomat/Other sound deadening stuff really work well enough to eliminate all that rattle? 2. Personally I can't stand the sight of Dynomat on the trunk, it just looks ghetto to me man!..what other options are there? 3. Ive also noticed that a majority of the rattle is coming from the rear bumper itself. How the heck do I stop that? 4. Can someone point me to a DIY or better yet, can you guys post pics of your trunk so I can see your setup? 5. How well does that home depot stuff works vs the real stuff? ...maybe I just have too much junk in the trunk. And I dont wanna end up like this fool << wrx youtube vid ( just terrible!)
Mad Mallard, Check to make sure your RCA cables are not crossing your amp power or ground wire anywhere. I had horrific noise once with an eD amp and moved the RCA's away from the power/ground wires and the noise went away. This was right at the location where the amp was installed. I have never had issues with noise in any of my 3 subaru's. Good Luck.
Since the noise goes away when the RCAs are unplugged I agree with this. I chased a ground loop in an old civic for a week. Re grounding several times, even grounding to the same place the HU was grounded too. I refused to believe it was the RCAs because they were high quality home stereo RCAs. Well, apparently not all shielded cables are created equal. I replaced with a cheaper car audio RCA cable and the noise was gone. Easiest way to check is just run them from the deck to the amp without running it underneath the carpet. At least you can narrow it down that way. Good luck!
At one point I ran them outside the whole car and still had noise when the ignition key was on, not the accessory, tho. This was weeks ago that I tried it.
Usually the RCAs are on one side of the back of the headunit and the power and ground are with the wire harness on the other side of the headunit. Just make sure they don't cross each other when you run the RCAs to the amp. Sounds like you isolated them under the carpet so you're good there.
well, i've moved the rca wire out of the car entirely while connected as a test and it didn't help. I don't think it crosses behind the HU, but i'll check. The HU is grounded to the frame its mounted with and to the harness ground. I'm confused how i get noise when ignition is on (not running,) but no noise on accessory.
still no solution, but i've found a temporary fix. I turned the gain control to the lowest level, and increased tghe gain from the HU. Its lowered the noise to where its not noticably while playing music... :/
It really sounds like you have either a bad set of RCA's or a bad amp....just sounds like something is grounding that shouldnt be. THe only time I had noise like you are describing is when I had a pinched RCA cable or a blown amp. What kind of amp is it? What is it running?
So you have the headunit grounded twice? Once via the chassis and also via the harness? That is suspect since in theory you created a loop. Disconnect one and see what happens.
that was the stock unit. It was grounded thru its harness and to its metal mounting bracket. the kenwood is just grounded thru the harness.
I had a similar problem recently with a Pioneer head unit. It sounds like your RCA's are grounding through your head unit. Doesn't really sound like a ground loop problem to me. On the Pioneers, there is an internal resistor that is prone to blow if you don't ground the the HU well enough. You have to ground the HU through the main wiring harness and run a seperate ground to the metal cage. Maybe other HU manufacturers have something similar? I blew mine and had to to get it fixed under warranty at a place in Alpharetta called something like Speedometer Service. They had it back to me in a week.
Sounds like you are getting feedback from the main electrical system. I had an old 63 Chevy 2 SS that you could hear when I turned on the windshield wipers, etc. The solution was running a heavier gauge ground wire to the amp and grounding it directly to the frame. Also curious what it is that causes heavy trunk rattle in these cars?
This sounds crazy, but try cleaning your battery terminals, and the connector that connects the Alternator to the Battery. pEd helped me do this about a week ago. I was having a light flickering issue, but also had engine noise and problems with my LCD screen not coming on. This fixed everything, and I no longer have any engine noise at all. The screen has booted up properly every time since, and their are no lines showing on the screen indicating a poor signal, etc... It may be as simple as this. If not, and you need some more help diagnosing what the cause of the problem is, hit me up.
It really sounds like you have a grounding issue. Is there anyway you can try a different head unit? One of the main culprits for the trunk rattle is the rear deck. I took some 3" foam and wedged it between the metal frame and the rear deck. It made a HUGE difference.
I guess another good question is how much power are you running wattage wise? Dynamat or spray on dampener gets rid of the rattling.