I saw this post on Love My Echo and just wanted to pass it along.
Amazon Echo Cases & Wall Mounts: Why Most Are A Bad Idea
http://lovemyecho.com/2016/02/12/amazon-echo-cases-wall-mounts-why-most-are-a-bad-idea/I'll add that I have the Fintie Protective Cases that April mentions in the blog post on my two Echos and while there is a very slight muffling of the sound with the cases on, it is not anything that bothers me at all and I like how they look with the cases on.
In other words, if you are thinking of buying one of those cases I would not let the blog post deter you from buying one.