Hollow sound??

[wareagle22]

What makes a call sound hollow with no rollover?  I've been fooling around with a different copper call and it just sounds hollow with no rollover??  No matter what striker I try, it's just a terrible sound.  This is a 3" pot call using bubinga wood.  I've tried using a thicker pot, thinner pot, thicker bottom, thinner bottom and have came to the conclusion that its either pedestal heigth or wall heigth that is causing it.  Any suggestions would be greatly appreciated. 

[ol bob]

1/8 inch gap between your sound board and the copper is a good place to start go down from there untill you get the sound you want.

[Gobblerstopper]

The pedistal too high can do it. 

Before you glue you copper in, lay it on a flat surface and make sure it's flat. If that makes any sense. A blank of wood laying on top of it and a good tap on the blank with a rubber mallet is a good way to check.