That basic format is geared to ease of tuning for sure. The 30 degree thing is irrelevant, but the radius transition between roundover & counter cut is the important bit. Essentially, the very peak that contacts the head is where all the action is. The more generous/softer the peak, the more easy it is to tune up (all other things being equal). The outer edge has a part to play too. With a straight (45 or 30 degree) cut, the film is taken through a more severe transition. With a radius to the outside, the transition from vertical tension to horizontal playing surface is more gentle. This has an affect too, although lesser compared to the bearing edge peak itself. To repeat, the inside angle (30 degree, or whatever) is almost completely irrelevant in itself.Andy,wouldn't Ludwig Legacy 3 ply maple/poplar /maple,which have an inner 30 degree bearing edge and a 1/8 " radius roundover be a forgiving drum to tune also.It seems like the ones I played,were a breeze to tune,and seemed to have a pretty decent range.
Unless I just got lucky.