Hi I came across this website and two audio articles on the subjects below on Clarinet Inconsistency
http://www.ridenourclarinetproducts.com/audionewsletterpage.html They're worth a listen.

Inconsistency in Clarinets:
the Causes and the Cure
An Anecdotal Reflection

Audio RCP Newsletter: May, 2008
Fundamentals and Pre-requisits for
the Competent testing of Clarinets and Clarinet Equipment