What do we really know about the transonic zone?

[beltfed]

Jim,
Re. your comments on stix barrel placement.
FWIW, I check for the node point on the barrel with a hammer handle: ring ring ring ring CLUNK ring ring ring, etc
Then I mark that spot with a piece of tape or yellow machine marker paint. That is the point I choose(try to remember to) place the barrel each time on my well felted stix.
Perhaps not the right place, but it is the same each time
arnie