Here are some helpful links you may enjoy.

If you have found some links yourself pertaining to DIY speaker building, email them to me. 

This is the Midwest Audio Club website page of someone who measured and made slight modifications to the DIY 3.1 Very good article.

This is a series of how to articles by Jared Kirby who also has a great site -  Kirby Meets Audio  for those interested in kit speakers.

Great website for anybody that wants to learn more about DIY audio