Originally Posted by Rockadian
Agreed about Pinstripes...if this still persists after trying different heads, take your rims and heads off and gently place the shell on a hard very flat surface. Shine a flashlight into the shell and take notice if any light comes through the bearing edge. Hopefully not the case.
Check the hoop to. If the hoop is bent your head will never be in tune. You can place the hoop on top of a table. Grab a piece of wood. Place it across the hoop and use one hand to hold the hoop down with the wood and the other hand to "tune" the hoop back into shape on the corner of the table by applying pressure to the hoop in a downward motion with your hand. Use small motions when calibrating the hoop.