Buzzin sound through Stereo problem

[RED2003COBRA]

This is probably a weird one, but my car has an intermittent buzzing noise coming through the rear speakers. It sounds like feedback and rpm's make the pitch of the buzz change. I'll pop the trunk to check is out and many times the instant I hit the trunk button, the buzz stops. The other day it stopped when I released my seatbelt. I took it to the dealer and they couldn't get the problem to present itself, but they sent the amp for the rear speakers to the shop. The "fixed" amp does the same thing. I'm thinking its the amp since when it's not plugged in the buzz goes away, but obviously so does the sound from the rear speakers. This issue is driving me crazy. Any thoughts about what the problem could be. Could it be a grounding problem with the amp like one of my buddies suggested? Thanks.

Lance

 

[CobraMac]

Well coming from someone who installed car audio for two years, it culd be one two things. 1) There IS a grounding problem like one of your buddies said and it is picking up the engine feedback...make sure all grounding wires coming from the amp are connected correctly and are not loose. 2) The power wire or, speaker wire is exposed and is running close to one of the other power wires. Literally there are 60 wires back there all in the same area. Make sure no wires from the amp are exposed. Make sure all connections are firm and not loose.

It could also be a few other things, but check that out for now. Also, do you have any aftermarket sound equipment in there? It could be a number of things if you do. Aftermarket deck? Speakers? An extra amp and sub?

 

[PistolWhip]

Do you have any stereo upgrades at all? All factory and never changed? That's probably the most important questions, but there could be some other things attributing to your problem.
This can happen if you take off the hood blanket (rare, but happens sometimes). The hood blanket is not just a thermal shield, but it is also designed to shield interference from the powerful ignition system. If you took that off, try putting it back on.
Another thing I'd look into is the main chassis ground strap. Make sure it's tight and that the points of contact are not dirty or corroded. Sounds far fetched, but everything grounds to the chassis and once there is a ground circuit malfunction or bad contact, it causes all sorts of weird issues that can be hard to diagnose.

 

[97CobraTT]

Well coming from someone who installed car audio for two years, it culd be one two things. 1) There IS a grounding problem like one of your buddies said and it is picking up the engine feedback...make sure all grounding wires coming from the amp are connected correctly and are not loose. 2) The power wire or, speaker wire is exposed and is running close to one of the other power wires. Literally there are 60 wires back there all in the same area. Make sure no wires from the amp are exposed. Make sure all connections are firm and not loose.

It could also be a few other things, but check that out for now. Also, do you have any aftermarket sound equipment in there? It could be a number of things if you do. Aftermarket deck? Speakers? An extra amp and sub?

I agree with this to the fullest...Any break in the insulation will cause interference. With a break it will just jump to whatever wire(s) that are around it. Take a peek back there and see if you can just visually see anything.

 

[RED2003COBRA]

Thanks for the replys. The sound system is stock all around and never touched. The hood blanket is removed, however, this problem existed long before I removed the hood blanket so I'm pretty sure the removal isn't the problem. The front speakers that are powered by the drivers side amp are totally normal. Only the passenger side amp powering the back speakers exhibits the noise. I plan on crawling in the trunk this afternoon to look for any loose wires. Thanks for the inputs.

Lance

 

[ALA G8R]

Does the buzzing go away when your fade to the front?

 

[RED2003COBRA]

Does the buzzing go away when your fade to the front?

Yes, it does. Soon as I fade the back up to normal levels, the buzzing sound comes out of the back speakers again. The buzzing is a definite radio interference type noise. I poked around today and couldn't find any loose wires are anything that looked like it would be a problem. Granted, I'm not a electrical expert, but nothing stood out to me. The fact it is intermitent drives me nuts. Why the heck would it stop sometimes when I hit the trunk release button. That seem so odd. Turning the stereo off then back on usually doesn't help. I drove around for a while with the rear amp unplugged just because it bothered me so much. The dealer has been no help, but now that I've done my mods, I'm very hesitant to take it to the dealer again unless I de-mod.

lance

 

[ALA G8R]

That tells me that the buzzing (noise) is in the pre-amp signal before it gets to the amp. The amp is just amplifying the noisy signal being passed to it. When you fade to front, the signal is attenuated and the buzzing stops. If it were the amp power/grounding then the buzzing would be present regardless of the signal being input into it.

You might want focus on the head unit as the problem.

Hope this helps.

 

[RED2003COBRA]

Thanks I'll look into it.

 

[RED2003COBRA]

Does the buzzing go away when your fade to the front?

Actually, It doesn't go away. Sometimes, just turning my stereo on and off will make the buzzing go away for a little while. It definitely buzzes even though I fade to the front. Sorry for the bad info.

Lance

 

[RED2003COBRA]

Anybody?

 

[HRSEPLA]

I have the same noise on my '03, did you ever find out what it is???

 

[PDubs]

Longshot here...do you have a Blackberry?

 

[Beetle6986]

Longshot here...do you have a Blackberry?

My 04 does it sometimes also. I just turn of the radio and turn it back on. Sometimes it take a couple tries to fix it. If that doesnt work , I just roll down the windows and listen to the exhaust. :rockon:

 

[RED2003COBRA]

Longshot here...do you have a Blackberry?

Nope. I'm deployed at the moment so I'll mess with it some more when I get home. Three guys now have this problem that I know of.

Lance

 

[mrose75]

Buzzing in sound system

(Merged thread)
Installed my new Pioneer AVIC X920BT and everything is working except now I'm getting at buzzing/whining through the sound system(not the Eaton for all the smart asses ;-)). Only thing I can think of is I had all the grounds going to one. Gets a little annoying. Any ideas? Thanks.

 

[xtremeskime21]

I have heard of people having that problem with the original head unit...I'd recheck your wiring imo.

 

[mrose75]

Everything works fine, I just hear the sound(more like a whirring) in sync with engine speed, at leastthat what it seems like to me.

 

[04redfireRO]

I would guess that there is a negative wire not doing it's job in your system. It is important to make the negative or ground wires as short as possible and tight to a chassis component. Check all ground wires for good connections to chassis and also i would relocate the grounds in to different locations and not all in the same spot. Also if your Pioneer doesn't have one, get a power supply harness with built in line filter to keep extra engine noises from coming in.The sound that you said it syncs with engine RPM is coming from the alternator as far as i know so you need one of those inline filters to stop it.

 

[mrose75]

I would guess that there is a negative wire not doing it's job in your system. It is important to make the negative or ground wires as short as possible and tight to a chassis component. Check all ground wires for good connections to chassis and also i would relocate the grounds in to different locations and not all in the same spot. Also if your Pioneer doesn't have one, get a power supply harness with built in line filter to keep extra engine noises from coming in.The sound that you said it syncs with engine RPM is coming from the alternator as far as i know so you need one of those inline filters to stop it.

I agree with the ground theory. Where would the online filter go?