it still might be your brake pads...does the noise get louder/more intense as you go faster? or is it more like if you're moving then it's there, but if you're stopped, then it's gone?

if you have a pneumatic jack or some easy way to get one or more of your wheels off the ground, try doing that and manually turning each wheel, and see if you can make that sound come back. this will also help you isolate it to a corner.