From Benade's book "fundamentals of Musical Acoustics" 2nd revised edition

Page 458

(b/a)2(L/te)=3.253

Benade states "this formula is easy to use" but it is only EASY if you know how!. and at the moment I don't

I am not too good with understanding formula, so can someone give me a simple approach to using this formula. Am i right in asuming the following...

b is the register hole radius

a is the bore radius at the desired register hole location

L is the distance from the cone apex to the centre of the tonehole for which the register hole is being designed.

te is the wall thickness of the neck + 1.5 times the register hole radius.

assuming that my above assumptions are correct then how do I do the maths

to make this = 3.253 ???

Many thanks to anyone who can help shed some light - so that I can understand more and continue with my experiments with register holes.

Regards,

Peter