ok simple question...

what makes this bov make its signature "whistle" when it blows off?


why i ask?... i had to take mine apart to fix the oring had some how blew around the bottom "plunger" so took it apart fixed o-ring, re assembled... now it no longer makes the whistle noise but sounds as if it flutters instead or just lets all the air out in one big whoosh!.



any insite on this i can take it back apart... do the 4 holes need to in the diaphram need to be pointing any certain direction?