This is an Do It Yourself project on Instructable.

These tree speakers were handmade from +14" thick sections of what was once a towering elm tree, that have now been transformed into a completely unique piece of hi-fi art.  The speaker enclosure is made from one solid piece of elm, sectioned only at the rear of the speaker in order to hollow out enough material to create the speakers internal volume of air.

Read more and create yourself one