Slight whine (from speakers? since new stereo?)

[Patriks7]

Hi guys,

I have been noticing the following issue ever since (I believe) I installed my new stereo - I don't think I hear it every time I'm driving, but there seems to be a slight whine coming, I believe from the speakers, specifically when I accelerate.

Video here, you can hear it slightly:
https://www.dropbox.com/s/xy1zr1xraq..._6965.MOV?dl=0

Any ideas what could be up?

[eskirvin]

Originally Posted by Patriks7

Hi guys,

I have been noticing the following issue ever since (I believe) I installed my new stereo - I don't think I hear it every time I'm driving, but there seems to be a slight whine coming, I believe from the speakers, specifically when I accelerate.

Video here, you can hear it slightly:
https://www.dropbox.com/s/xy1zr1xraq..._6965.MOV?dl=0

Any ideas what could be up?

I'm not able to listen to your file, but the description matches a ground loop problem. If I remember from things I've read correctly, BMW uses a floating ground for their audio system, so if you introduce a piece to it, you'll be creating a ground loop.

If you've replaced the entire system, make sure not to use the BMW supplied ground wires from the harnesses, make your own. Use wire equal in size or larger than the power wire and attach it to a spot free of any paint. I use crimped on and soldered ring terminals.

Multiple audiophiles websites will strongly suggest every piece of equipment be grounded to the same point on the chassis to avoid loops, but I haven't found that necessary yet.

[Patriks7]

Originally Posted by eskirvin

I'm not able to listen to your file, but the description matches a ground loop problem. If I remember from things I've read correctly, BMW uses a floating ground for their audio system, so if you introduce a piece to it, you'll be creating a ground loop.

If you've replaced the entire system, make sure not to use the BMW supplied ground wires from the harnesses, make your own. Use wire equal in size or larger than the power wire and attach it to a spot free of any paint. I use crimped on and soldered ring terminals.

Multiple audiophiles websites will strongly suggest every piece of equipment be grounded to the same point on the chassis to avoid loops, but I haven't found that necessary yet.

Hmm that would sound about right.

Just to clarify, I have changed the screen up front and connected it to the trunk with the long cable.

Interesting that I have not seen this discussed anywhere in any of the aftermarket stereo guides (or did I just miss it?). Is there any guide or recommendation on how to best go about this? Wouldn’t be a big fan of screwing up my cable and having to get a new one and redo the whole process of taking apart half my interior

[Patriks7]

Also, I can’t seem to open the video either when I’m not logged in, any suggestions where else I can upload it easily?

[X5only]

I can open it fine (don't even have an account for the site and dismissed the login prompt) but I can't hear that whine ... may be I'm poor of hearing these days

[Patriks7]

Originally Posted by X5only

I can open it fine (don't even have an account for the site and dismissed the login prompt) but I can't hear that whine ... may be I'm poor of hearing these days

Funny, now it works again. It's about halfway when I accelerate, very subtle though. I wanted to do another video today where it would maybe be heard more, BUT today it didn't make a peep! Sometimes I think this car is just mocking me

[eskirvin]

Originally Posted by Patriks7

Hmm that would sound about right.

Just to clarify, I have changed the screen up front and connected it to the trunk with the long cable.

Interesting that I have not seen this discussed anywhere in any of the aftermarket stereo guides (or did I just miss it?). Is there any guide or recommendation on how to best go about this? Wouldn’t be a big fan of screwing up my cable and having to get a new one and redo the whole process of taking apart half my interior

The cable, that 6 meter fella, has a connection for the ground on your new stereo. I'd guess it is much like mine. If you think of it as a 6 meter antenna, picking up whatever it can on its 6 meter journey, you'll get why it isn't the best way forward, but it was very easy, right? I had a whine that disappeared after I tapped a hole in that bracing behind the stereo, the big metal piping, and grounded my Android head unit there.

As you've probably observed, and noticed from the price point, these Chinese head units are mass produced and although they work, they aren't any audiophile's dream. I suspect the grounding for the RCAs might not be dealt with properly resulting in any RCA cables making another ground loop. The ground near the head unit fixed my issue, but manufacturing differences could mean you need a different solution. It is a simple thing to try.

[Patriks7]

Originally Posted by eskirvin

The cable, that 6 meter fella, has a connection for the ground on your new stereo. I'd guess it is much like mine. If you think of it as a 6 meter antenna, picking up whatever it can on its 6 meter journey, you'll get why it isn't the best way forward, but it was very easy, right? I had a whine that disappeared after I tapped a hole in that bracing behind the stereo, the big metal piping, and grounded my Android head unit there.

As you've probably observed, and noticed from the price point, these Chinese head units are mass produced and although they work, they aren't any audiophile's dream. I suspect the grounding for the RCAs might not be dealt with properly resulting in any RCA cables making another ground loop. The ground near the head unit fixed my issue, but manufacturing differences could mean you need a different solution. It is a simple thing to try.

Great, that makes a lot of sense, I will look into doing that. I just noticed that the GPS has become flaky in my unit again (already had a replacement about 6 months ago due to the exact same issue), so I will need to take care of that first. Thanks.