I've got a strange noise that is on constantly once I hit around 25mph. I think it sounds like it is coming from the front left but it maybe a bit more central. I had discs and pads all round just over 200 miles a go and the front left had a new caliper as after fitting the new brakes, it seized so may have warped the disc slightly.
The noise is more of a whirring noise instead of a whining noise if that makes sense. I also rotated the wheels at the same time as doing the brakes.
It's a 05 wrx, about 88000 on it. It feels fine to drive.
Any ideas?
What do I have to look out for if the diff is starting to go?
Could it be a wheel bearing?

 

Could be the abs tone ring cracked when changing the brakes............just a guess

 

Would that bring the ABS light on? How easy is it to fix that and is there any way I can see the problem myself? Is it obvious?