I would agree with the above ,,lots depends how maker designs a call mine the glass -glass run med. higher pitched sharp roll over with real nice rasp to it ,,, glass slate they still got a higher front but the roll over is not as sharp and got a deeper raspier sound ,,, but on the later a tighter striker hold can make a difference when running glass slate ,,,, glass wood I have made a few but never realy dug in to them