Why are there so many wooden box speakers out there?

"We are simply saying why are all speakers wooden boxes when the reserach has shown that they should be spherical? "

Now, what research are you referring to? Can you provide a link? 

@dill 

yes heres a link

@kenjit

yes here’s a link

Interesting how close the two 'truncated pyramid and parallelepiped’ examples were to the sphere. And better than the hemisphere. Andrew Jones should be stoked.

But note the somewhat limited scope of measurement: 100-4000 Hz and single point microphone. A good start but you’d probably take the investigation further. Interesting also that the discussion focusses on diffraction rather than internal dynamics.

We also have to consider the compromises involved in full-range or co-axial driver implementations. The former especially with respect to suitable SPL and dynamics, the latter with complex diffraction from the drivers.

Look at KEF Blade for example: co-axial treble/mid but separate bass drivers to achieve sufficient dynamics in the lower octaves (Devialet adhere more closely to the sphere but take a similar approach).

@Kenjit:
Who was this speaker designer? Can you show us how and why he/she reached these conclusions?

Wood is used cause it's an insulator, by insulating the current you increase efficiency.  If you have no wood you have no joy.