Galaxy S4 Passive amplifier speaker

I needed to have both my hands free while on speakerphone so I have designed this.
The phone speaker has a channel to the open bar below amplifying the sound. I have also made a small hole for the mic.
Works for me...

I used raft and supports. The raft separates easily but the supports in the output space are a little harder to remove. They do not however need removing as they are "holey". Maybe try it first.
Just wanted to add that I have a Gel case on my phone for this design...

Enjoy!