Hollow sound in pot call center

[longbearded1]

What can be done to eliminate this? Edges sound good Center very hollow. Will making shelf wider for playing surface make a difference, not making bottom too thin?

[mastevt]

Shorten up your distance from the underside of the soundboard to the bottom of the call, which I call the back wall.  Also thicken up that back wall a bit.  I like it around 1/4. 

[longbearded1]

I will try that sir, thanks!!