Of the three 12" (30.48cm) toms I've owned, one (a 1984 Gretsch USA) was absolutely impossible to tune, period. Nothing I could do would get that drum to behave. The other three — no sweat. All four 13" (33.02cm) toms complied with my tuning instructions without complaint. The Gretsch may have been slightly out-of-round, although I don't remember it having a problem with heads fitting. It was just plain ornery.A 33,02cm drum is no harder to tune than a 30,48cm one
Mongo, I kick myself daily because there was a 12x15 Phonic tom a few weeks back on Reverb and I didn't get it...always loved 15" floors...12x15. the most versatile. tune it way high or tune it way low and it sounds GREAT !