Is this normal (white noise through speakers when car is off)

[TypeRx]

Hi guys:

Question for those of you with a B7 (mine is an RS4 with RNS-E). Regardless of how long my car has been off, I can hear faint white noise coming from the speakers. The sound is similar to what you might hear from relatively quiet HEPA filter.

I realize that the audio system on this car can be powered on for a period of time after keys have been removed from the ignition. Curiously enough, I can leave my car off for 24 hours and still turn the radio on/off (with no keys). Also, I can't get a remote on/off to work from the wiring on the amp in the trunk.

So, is my car possessed or is it just me? Does anyone else's car produce white noise whenever off?

[05.5SilverS4]

Youre radio will always turn on when they keys arent in the car. As far as the white noise, i cant help you with that, mine doesnt make it.

[405Z]

Mine does the same. The white noise isn't on all the time, but starts up once you open the door. I'm wondering if it has something to do with nav, as all 3 of my current cars have nav and they all start hissing as soon as I open the door. None of my previous cars did it, and none of them had nav.

[drew]

its the nav

[charliemike]

its the nav

I have it too, so this is good to know.

It's also nice to own a car so quiet I can hear it :)

[iconoclast]

are you referring to the fan in the rns-e?

[TypeRx]

Guys, the noise definitely comes from my speakers (all of them). It is faint and sounds like a quiet hepa filter.

As an aside, why in the world would Audi design the stereo to operate indefinitely with no key in the ignition? I can understand a few minutes...but until the battery is dead?

[RAudi Driver]

I'm sure it's a normal thing. My B6 did it or maybe it was my B7, I can't remember but one of the cars did it.

[S4pedro]

In my 05 B6, stereo only runs about 15 minutes with key off.(no nav).

[drew]

Guys, the noise definitely comes from my speakers (all of them). It is faint and sounds like a quiet hepa filter.

As an aside, why in the world would Audi design the stereo to operate indefinitely with no key in the ignition? I can understand a few minutes...but until the battery is dead?

the faint hum from the speakers is caused by the nav because it runs even after you turn of the ignition to completely shut down. some are louder then others in this respect.

[justinperkins]

why in the world would Audi design the stereo to operate indefinitely with no key in the ignition?

All VW and Audi vehicles have been doing this for quite some time. It's handy if you're sitting in your car or maybe you're parked somewhere with the doors open. Somebody said it only runs for 15 minutes but I thought it was more like an hour. Whatever, it says in the owner's manual how long it will run.

[handyvorb]

Yup exactly ^, don't forget bluetooth and Onstar also use the speakers.

[Philosophyy]

This doesn't happen with me but, I am also very hard of hearing. Maybe It does happen in my car as well.

[handyvorb]

Yes, I haven't personally heard the white noise from my speakers with the RNS-E (I have the bose speakers). I haven't got down close to them to try and listen for it. If it's actually loud, I would say the coding or adaption may not be quite right (maybe the bose equipped selection) and to re-check those.

[sear]

I've got the RNS-E with Bose speakers and I hear this noise sometimes too. It's been happening for a while, but I havn't really been too worried about it.

[GotRS?]

Just timed mine. A few seconds over one minute. The level is high enough to turn on my auto sensing sub amp. Still find it odd to turn the amplifiers on without the head unit being on?

[Retsujou]

Sometimes people hear a sound which is the low pressure fuel pump priming the lines. Is that what you are referring to? it happens once you open the door after unlocking the car and has a slight whooshing/white noise sound to it.

[zx9]

Yah its normal, mine does it as well. Kinda sounds like a low level hiss from the speakers.

[TypeRx]

Just timed mine. A few seconds over one minute. The level is high enough to turn on my auto sensing sub amp. Still find it odd to turn the amplifiers on without the head unit being on?

Agree -- I think this might be why the remote power lead I am using from the bose amp runs hot all the time. It sucks -- I have to pull a fuse everytime I want to shut the amp off.

[PetrolDave]

Still find it odd to turn the amplifiers on without the head unit being on?

The head unit IS on, but in a "hidden state".

When you unlock the car the head unit is booted up - this gives it more time to boot up (initialise the sat nav, read the map, get a GPS fix, etc.) - but it displays a blank screen until you turn the ignition on.

Similarly when you turn the ignition off it doesn't actually turn off the head unit, it again goes into this "hidden state" which it only exits when you either lock the car or after around 30 minutes. This is so that it won't have to reboot if it's only a short stop.

The amplifier enable line is (unfortunately) taken active even when the head unit is in this "hidden state" - hence the hiss from the speakers even when the head unit is apparently off.