I just recently updated from using Luna to Freya (I basically ereased my drive and went with a fresh install from 0), and I have been getting this popping sound when I shut down my laptop (Lenovo Y410P). This had also happened to me before back when I used Luna, but I was able to fix it doing some google searching (I believe this is the solution I used https://askubuntu.com/questions/160882/popping-noise-from-laptop-speakers), but this doesn't seem to work on this new kernel.
I've been trying to find a solution on my own to no success; I'm a very superfluous Linux user so I would really appreciate some help here. Any information needed that can be of help I will provide as fast as possible. Thanks in advance.