After thinking and researching I have decided to build an experimental acoustic guitar. In order to increase the sound volume by increasing the board vibrating area, I will make the following changes:
Two sound holes - one on the upper side for the player to hear the sound better and one on the bottom side, directed towards the audience.
Floating fret board
No upper bout (water drop style)
New top braces layout (leaf veins style)
New bridge design
To make the guitar more ergonomic while playing, I will make these changes:
Heavy kerfing and no purfling, round over or chamfer on the joint between the top and the sides will reveal the kerfing (Emboya wood) will be more comfortable to play
Back and sides: African Black wood.
Top: AAAA Caucasian Spruce.
Braces: Sitka Spruce.
Fret board and bridge: Rosewood.
See my work at Martin Koch's site: