Ive read the manual and watched the video about ground balancing. The manual says to set the threshold until it barely makes noise then lower it to the ground. My machine is to sensitive and any movement makes it scream.I cannot ground balance it that way .Its impossible.I have to turn the threshold up some, only then will it stabilize to where i can pump it up and down and it doesnt scream. Ive been using it that way but is it correct?