just turned a bloodwood pot.i used crystal with a glass soundboard.sounded kind of hollow like there was too much space in the pot.i took the crystal back out and put 2 sound boards glued together ,put another crystal surface on.it sounds killer.has anyone else did this.
Also you can make the port hole by working them out a little at a time bigger and that hollow sound will start to disappear I had a call that sounded lik junk opened the hole sound move the right direction little bigger and it was right on guess there all kinds of ways to put fires out!