Weird squeal from rear passenger speaker

[meisanerd]

OK, so possibly a bit of a fun one. Haven't had the time to do much troubleshooting yet, but figured I would see if any of you guys have advice on what to look at.

The rear passenger speaker has recently (past week or so) started doing a high-pitched squeal. It seems to be directly related to the RPM of the engine, the higher the RPM, the louder and higher the frequency. It is barely perceptible at ~500, but is very noticeable above the music at ~2500. Turning off the head unit or changing the volume on it makes no difference. The sound happens regardless of which gear I am in, and also happens when I am in neutral. It seems to happen if the rear passenger door has been recently (past couple of hours) opened, but goes away if the vehicle has been sitting for a while turned off.

Not sure if any of this applies, but I have an aftermarket head unit connected to the factory Rockford Fosgate amp via the pre-outs through a ground loop isolator.

 

[Prime]

Do you have the RF system?

 

[meisanerd]

Answered in first post... but Yes, I do.

 

[Prime]

Haha. I read good.

Mine does it too. Intermittently. Also with aftermarket head unit. I figured it's something to do with the amplifier. Check all of your connections under the passenger seat.

 

[JeffPro4x]

Mine also does it. Is it possible interference from the cb antenna cable? Mine is routed in that area.

 

[CHUG]

Long shot.
try your balance Fade button.. shift sounds to front speakers.. If get the whine?.
if it moves to the front speakers. Would suspect a Alternator noise. Since its RPM created.

check ground cables, shielding, loose speaker wires?. Dunno.

IF your keying up the CB and get that whine.. I know its RF Noise.. Two fixes. Add Ferriate beads to the Coax cable an power cables. Noise goes away.
Then toss CB in trash.. For its issues... Been thar done that.!. CB was Issue.. $30.00 in ferriate beads solved it for a dang Radio with 2 mile Range..

it's all I got. time for a beer!!!

 

[General_Tarfun]

IME noise like that is usually a ground issue somewhere along the line. Is that an original speaker btw? I'd pull it to get a look at the connections.

 

[meisanerd]

Mine also does it. Is it possible interference from the cb antenna cable? Mine is routed in that area.

No CB installed. Was planning on getting a HAM setup, but I've been too busy/lazy to get my license, and it would just add another hobby to spend money on...

Long shot.
try your balance Fade button.. shift sounds to front speakers.. If get the whine?.
if it moves to the front speakers. Would suspect a Alternator noise. Since its RPM created.

check ground cables, shielding, loose speaker wires?. Dunno.

IF your keying up the CB and get that whine.. I know its RF Noise.. Two fixes. Add Ferriate beads to the Coax cable an power cables. Noise goes away.
Then toss CB in trash.. For its issues... Been thar done that.!. CB was Issue.. $30.00 in ferriate beads solved it for a dang Radio with 2 mile Range..

it's all I got. time for a beer!!!

It happens regardless of whether the head unit is on or off, so I am not sure adjusting fade/balance will affect it, but I will try. Doesn't hurt, and it could narrow down where I need to look...

IME noise like that is usually a ground issue somewhere along the line. Is that an original speaker btw? I'd pull it to get a look at the connections.

Current theory between me and my mechanic buddy is that there is a loose cable in the door, as it seems to pop up when that door is used. We are planning on popping the panel to get a look at the connectors next time we get a chance to meet up, just figured I would ask all the smart guys on here in case some of them knew something obvious.
It is the original speaker and connections, so it wouldn't surprise me if something is loose given the age and mileage of the vehicle.

I had a couple minutes to quickly fiddle with the connectors on the amp last night, didn't seem to have an effect.

 

[General_Tarfun]

it seems to pop up when that door is used.

Oh in that case it's probably an easy fix assuming the speaker hasn't been damaged yet. You'll probably find a worn through or loose wire in that door. Could be where it passes through the boot into the frame if that door has been used a lot. That panel is easy to remove you just have to be careful not to scratch or dent the plastic up.