So, over the last couple weeks, I have noticed a very faint metallic ringing/whistling sound from the right rear. I usually start to notice it around 10+ MPH, and can somewhat hear it at most highway speeds before road and wind noise overpower it. On certain roads(mostly freshly paved roads), it's less noticeable. It seems to be in tandem with the tire noise. It's not a rotational noise, and the pitch of it does not change. So I'm starting to think it might be some type of resonance sound caused by the tires. Like I said, it's extremely faint, but I know it's there. Windows have to be up, radio off, to hear it.

This is how my car sits right now:

-Rear wheels are 17x9 +40 with 255/40 RS3s
-KW V3s(car is lowered but not slammed)
-Alignment out back is -3.5 camber and OEM toe settings(can't remember the exact numbers).

Not sure if it's in my head, but it seems I started noticing this sound right after I had the alignment. Before the alignment, the rear camber was at -3. Could bumping up the camber half a degree really change the road noise the tire is making and possibly make a resonance sound like this? Like I said, it almost sounds metallic, but at times sounds like just some high pitched tire/road noise. I pulled off the rear wheels today, and inspected the calipers and pads, and found nothing. Reason I'm thinking this is more of a resonance sound, is because the pitch of it never changes... i.e.; it doesn't get louder or more high pitched the faster I go.

I was thinking wheel bearing possibly. But after researching that a ton on this site, it doesn't quite match up. Any help/input would be greatly appreciated!

EDIT: Also, thought I'd add, that the sound is not changed by applying brakes, clutch in, accelerating, etc.

 

Bump.

Still notice the sound. Hasn't gotten louder though, just still there.

 

I have the same noise as well but I noticed when I let off the throttle just a tad bit. Its not a constant sound. For me, its only when I gently let off the throttle at highway speeds around 3-4k rpms.

I'm not exactly sure what it can be. I had the back end of the car in the air and shook parts around without any luck. No bearing play either.

 

Pulled the caliper and rotor off just to inspect everything. It all looks good, and the sound is still there. I need to get a different set of wheels and tires out back to see if anything changes.

 

Figured I'd bump this...

The rear tires were at 30 psi cold, so I bumped them up to 33. After some driving, the sound I heard before is different and much more faint. So I'm guessing it's just some weird tire noise I was hearing. I also noticed that the rear right RS3 has some cupping to it. Didn't expect these tires to last too long anyways.

 

Another bump...

Have noticed on right turns at speed or just weaving the car back and forth, the noise will get a tad louder on the back right side. Only when it is unloaded though. When I load the back right side, the same noise isn't there. I've heard of people say that a bad wheel bearing will make more noise when you load the bad corner, but this isn't the case. Only makes the noise when the corner is unloaded. Different noise due to less weight on the back right tire?

Any help would be greatly appreciated!

 

Anyone?