Wayne Parham Messages: 18791 Registered: January 2001
Illuminati (33rd Degree)
I suggest CARA. There are online room calculators, but they only show the frequencies where standing waves are produced, not the positions of the nulls and peaks. At low frequencies, i.e. first axial mode, they line up pretty evenly. But above that, sometimes the modes interact with one another and bunch up in odd places.