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Speaker Static with the Radio Off???

69K views 52 replies 23 participants last post by  Peepg 
#1 ·
Yesterday I was treating the leather in my CS. I was sitting on a stool next to the driver's door and I heard a high frequency hiss. I determined the noise to be coming from the mid-range speaker on the door. The radio was off and the key was not in the ignition. I checked the passenger’s side but did not hear anything. I then checked Her987CS's CS and heard exactly the same thing on the driver's side and again nothing on the passenger’s side.

Has anyone else noticed this, and does anyone know what could be causing it?

Mark
 
#2 ·
Yesterday I was treating the leather in my CS. I was sitting on a stool next to the driver's door and I heard a high frequency hiss. I determined the noise to be coming from the mid-range speaker on the door. The radio was off and the key was not in the ignition. I checked the passenger’s side but did not hear anything. I then checked Her987CS's CS and heard exactly the same thing on the driver's side and again nothing on the passenger’s side.

Has anyone else noticed this, and does anyone know what could be causing it?

Mark
Could be a phone interface. Do you have the Bluetooth kits installed? They use the amplifer and the speakers on one side (programmable). This wake up of the amplifier could result in a little noise floor (hiss).

Check the TP button and the programming of your radio.
 
#3 ·
Gator, thanks for the quick reply,

No Bluetooth in either car. I initially thought it might have something to do with the 9500ci install I just completed, but when I also heard the same static comming from my wife's car (her car is totally stock with the same options as mine except I also have PASM) I figured it had to be something from the factory. I suspect if you listen to yours you might hear it also.

Mark
 
#6 ·
Do you have any aftermarket electronics in your car? stereo, radar or otherwise?

Initially when I had my SRX installed the speaker was mounted behind the center console too close to the main power line that runs from the battery down the center of the car, The speaker was picking up feedback and broadcasting an annoying high pitched wine, it's pitch would change with RPM. Moving it a few inches away fixed the issue.

In past cars I've had the same sound due to a bad electrical ground, I believe its called a "ground loop", though never heard of these issues in our cars.

Best of luck with troubleshooting the noise.
 
#52 · (Edited)
Several years later.... Sorry for the thread revival, but this is the best reference I could find to my own issue.

BLUF (Bottom Line Up Front): Anyone know where I can find the "GP Electronics electrical ground point?" Ie. where is the "Middle Support Frame?"

Background: I have the same high-pitched whine that fluctuates with RPM described by Blitzkrieg (back in 2009), but everything I have is stock (newly purchased pre-owned 2009 Cayman S with the CDR-30 headunit, no Bose). I also have the constant low-volume static in the background whenever the radio is on described by a number of other people with the CDR-30, but one problem at a time...

Both of these problem sounds are fixed by turning the stereo off (insert obligatory comment about leaving the stereo off and just enjoying the sound of that 3.4 engine sitting behind me... fair point). Additionally, disconnecting the amplifier in the frunk doesn't fix the sound, so I think my amp may be okay at this point. Finally, I did some reading up on "ground loops" and eliminating stereo system "noise," and I think the best initial step for me is to check my electrical ground for the system, just in case it is loose or is a bad connection. Then I found the 987.1 Wiring diagram provided by KS-CS (seriously, planet-9 is awesome), and I tracked down what I think is the correct ground (on pg 48/145). It shows the ground location as "GP Electronics (Left Side of Middle Support Frame)."

I hate to show my ignorance, but this doesn't really help me much. Can anyone here fill me in on where on the car I should be looking to find this? I'd move on to something else in the meantime, but this seems like the most obvious/easiest fix to try first.

Text Diagram Plan Technical drawing Floor plan
 
#8 ·
I believe this might have something to do with cell phone signals passing through unshielded wiring in some electronics... did you have your phone on you? Often, if I have my cell phone on a night stand next to a bed while staying in a hotel, I hear intermittent buzzing from the clock radio, even though it's off. In my 996 turbo, I at first put my cell phone in the small cubby-hole under the radio and A/c controls - like the empty spot we have in the Cayman, and got all kinds of interference - when removed, the audio system worked fine - in fact, when I was keeping it there, you actually got advanced warning of a call coming in - the audio system would explode with loud interference, and then the phone would ring a few seconds later. In the newer cars (997/987) they seem to have shielded the wiring better - I keep my phone down there now, and there's no noise.

brad
 
#9 ·
You should note that there is a delay in your radio turning off completely. When you remove the key and exit the vehicle, the radio receiver electronics will turn off immediately, it will however not completely turn off and will keep the external amplifier powered. The radio itself does not go to sleep immediately. It stays in a standby state for about 5 minutes, with the external amplifier powered on. This will result in some noise coming from the speakers. The noise is at a very low level and difficult to hear unless you are looking for it. I have noticed this if you leave the radio ON button, ON all the time and rely on the removal of the key to turn off the radio. If this is the case, you will find that the external amplifier turns on as soon as you open the drivers side door and you will hear the amplifier noise as well. This external amplifier enablement functionality is controled by pin 5 in the "A" ISO connector on the CDR24.

timbucthree
 
#10 ·
Thanks for this, very informative.

I normally keep the radio off and so I do not think that this is what is occurring. But just to be sure, tonight when I get home I will open the driver’s door, ensure that the radio does not come on, and check for the noise again.

The other issue is that I am only hearing it out of the driver’s side. There is no noise coming out of the passenger’s side. I would assume that if the amp is up and active I would hear noise floor levels out of both sides (the speaker balance is centered).

Also no cell phones anywhere around the car.

Mark
 
#11 ·
Very interesting. Mark I can assure that in time your ears will not hear that faint noise (I just tried various scenarios described above and heard nothing but it would have to be pretty loud to compensate for ears subjected to the R&R habits of my youth)...it may require another 20 or 30 years but what the heck.
 
#13 ·
:hilarious: I love this! Santa Fe you are right. I just need to be more patient and give it some time. ;)

I've noticed the same sound and theorized that part of the sound system is used to make the assorted chimes used for warnings both useful and others not so much. Seat belts, lights on, key in the ignition etc. Using the existing sound system would negate the need for separate noise makers. I've no proof one way or the other though.
This makes sense to me. I did another check yesterday and there is hiss coming out of the passenger’s side but at a much lower level. I suspect the warning/alarm system is tied into the sound system and so the speakers are always in a quiescent active state. The noise floor for the system does seem a bit high however. But I guess for a stock car audio system this is to be expected.

Mystery solved. Thanks everyone! :)

Mark
 
#12 ·
I've noticed the same sound and theorized that part of the sound system is used to make the assorted chimes used for warnings both useful and others not so much. Seat belts, lights on, key in the ignition etc. Using the existing sound system would negate the need for separate noise makers. I've no proof one way or the other though.
 
#14 ·
Actually the real solution is for one of us to get ambititious enough to do more than armchair experiments to verify. Shouldn't be hard. An ear by the speaker and make it sound some warning. The key in ignition, lights on or similar should be easy. I've just always had something with more priority while in the CS.
 
#18 ·
Re: speaker noise

door locked with alarm- noise gone
door locked - noise
door unlocked - noise
both speakers
I have not noticed any sounds like you describe, but a little more information might help me reproduce the sound, as I have the Bose system.

Is the power on for the Bose when you hear the sound? If so, what is the volume, and does this occur while playing the radio or a CD?
 
#20 ·
Re: speaker noise

Okay, I went out to my car and confirmed that the noise is present in it too, and just the way you describe it. It emanates from the smaller of the two speakers in the doors (and from no other speaker in the car), and is a little louder in the driver's door speaker. The buzz/hiss stops a few seconds after the alarm is engaged. When I disengage the alarm the buzz/hiss does not return until I open the door.

I suspect this is normal seeing as you and I have confirmed its presence. Maybe somebody that fully understands the electrical interaction between the Bose and the alarm system can explain why this occurs.

If you don't mind, would you read the thread I started in the electronics subsection, titled "TP and Popping Sound?" I am curious if your Bose makes the same occasional sound that mine does. I had only one reply and that fellow said his did not make the sound I have heard.
 
#22 ·
Re: speaker noise

Okay, I went out to my car and confirmed that the noise is present in it too, and just the way you describe it. It emanates from the smaller of the two speakers in the doors (and from no other speaker in the car), and is a little louder in the driver's door speaker. The buzz/hiss stops a few seconds after the alarm is engaged. When I disengage the alarm the buzz/hiss does not return until I open the door.

I suspect this is normal seeing as you and I have confirmed its presence. Maybe somebody that fully understands the electrical interaction between the Bose and the alarm system can explain why this occurs.

If you don't mind, would you read the thread I started in the electronics subsection, titled "TP and Popping Sound?" I am curious if your Bose makes the same occasional sound that mine does. I had only one reply and that fellow said his did not make the sound I have heard.


I have the same as you.. alarm, door etc etc Professor
 
#23 ·
Re: speaker noise

Thank you—I found that discussion informative. Like you, I am willing to bet that this low-level noise is present on all cars, its just that you really have to listen for it, as typical background sounds mask it.

Seeing as you have good ears :))), might I implore you to look at a thread I started in the electronics subsection regarding the TP button and a popping sound?
 
#34 ·
Re: speaker noise

To add another data point: I have this hiss/static too.

I have a gen 1 with Bose and PCM. I always leave the PCM on when I turn the car off (which means the radio is on). Last night, I was getting something out of the footwell and heard the static. I had to put my ear right next to the speaker to hear it. This is with the key out of the car. I just verified it this morning. The car has been sitting over night, I opened the driver's door, and heard the hiss. I leave a CD in the drive and I can hear the CD drive spinning up when I open the door, so obviously something is powering up when the door is opened. This is before I put the key in.

I suspect this is normal.
 
#38 ·
Re: speaker noise

I have the hiss as well. If this is really in every car, some of you guys need to get your ears checked, as it is quite noticeable before you start driving around.
Sorry for thread revival, and by lack of clarity in the original thread I guess there's no easy fix to this, but the static hiss from the smaller of the door speakers is super annoying.

Basic CDR-30 in a 2010 Cayman S.
Static really noticeable with either radio on (ignition off) or ignition on (radio on / off or mute)

Too old for warranty so may have to find auto-electrician if not a simple fix.

Any ideas?
 
#36 ·
So changing the amp was the solution for people who had this problem?

My 2011 Spyder just started doing this and I'm 100% sure this sound wasn't there when I first drove off the dealer lot.
The static/buzzing sound is coming from over left and right front dash mount speakers near the A-pillar on mine and it's driving me CRAZY! :(

When I get in the car and plug the key in, nothing, no sound but as soon as I turn the key, not even engine started, static/buzzing sound starts and doesnt go away until I take out the key.

I tried to turn off the audio/headunit and it's still making that noise...:crazy:
My car is equipped with bluetooth, CDR-30, regular audio system...
Can someone please help me out to fix this problem?... So I don't have to bring my car to the dealership?
Warranty or not I HATE going to dealerships....:helpme:
 
#41 ·
What sound solution do you got? Bose or Sound Package Plus? The latter has the amp placed in the trunk, and can easily be disconnected by pulling the plug on it.
Some of the Sound Package Plus ASK-made amps have a history of failing, either ending up completely dead or develop hissing/rumbling or a very high distorted volume level. All this can be fixed by modifying it, and to a lower price than getting a new one.
Cheers,
Tore
 
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