i plan on making a slate and glass call...i want the best sound i can get and heard a sound board is needed....should htat be slate or glass?? which works best and has the best sound you think?? i will make 1 slate and one glass..but what should be under the slate and glass? thanx..im not sure if i want a slate over slate or slate over glass or a glass over slate or over glass or what...what do you guys think? also does the wood of the pot make a diffrence? like oak cherry maple ect?? will that effect sound at all or is it all looks?? thanx...