Acoustic Diffusor, Basic

I came across this calculator for an acoustic diffusor and whipped up a basic static model of it:

http://www.mh-audio.nl/DiffusorCalculator3.asp

My model has a column width of 1cm and max column length of 1cm, which results in low and high frequencies of 17200 Hz, and you can scale the model to tailor it to your needs:

Z scale factor = 17200 / desired low frequency (Hz)
X,Y scale factor = 17200 / desired high frequency (Hz)

Put another way:

Low frequency (Hz) = 17200 / Z scale f