I put new brakes Pads & Rotors on last weekend and noticed today (rainy day), that their is a slight rubbing noise from the rear back wheel.

Sounds like (whomp...whomp...whomp). When I press on the brake and slowing down, the noise is still there, which seems like it wouldn't be the brakes?!? Would it. There doesn't seem to be excessive heat from the one wheel either which I would expect from brakes.

Any ideas? Wheel Alignment?

 

My fronts did the same thing with new Brembo rotors and carbon-metallic pads. I did 3 things: Cleaned the rotors with brake cleaner to remove all residue, use some emory paper and lightly sanded the rotors in a circular motion to give the rotor a non-directional scuffing, then I swapped rotors from side to side. All has been well since.