pot call is a typical round slate call, like a primos or woodhaven. The base looks like a pot, so hence the name pot call
The slate thickness WILL affect the tone quality, as does the distance it is from the bottom, number of holes, how far your sound board is from the slate (or how close it is) and how far it is from the bottom of the slate, not to mentoin the wood the pot is made of and the type of peg you are using.
Lots of variables.
I did some zebra wood calls last winter, they pretty much all sounded really nice, but one....and it still worked fine.
Calling is rythm, not how well you sound. Some turkeys are the most horrible sounding callin the woods. Say the right words in the right context and at the right time, it wont matter!
Try it, you wont be dissappointed.... a hack like me can build them, anyone can.