Posted by olituba on December 01, 2001 at 17:48:12:
In Reply to: Re: False tones... posted by Why??? on November 30, 2001 at 17:03:07:
Either I canīt read or my english is just too crappy, or the actual question wasnīt answered at all so far!!
Now, here comes my answer to what I understand as the question:
Now, neither a trombone nor a tuba are strictly cylindrical, the tuba even less so. On a strictly cylindrical tubing in my information that false note is very close to the 2nd natural. I havenīt tried that out, yet, for lak of a piece of straight, cylindrical tubing in brass of some 20 feet length... Take a trombone, now, and you get a more conical tube, the note moves downward to somewhere near a fourth ( = low f or close to that). Go to the next more conical instrument, i.e. tuba and it moves even further down to a 5th (= EEb or near) that.
Conclusion: Going from cylindrical to partly conical in just a slight way to partly conical in a stronger way to ( takeing the other extreme) strictly conical in a very strong fashion that false note moves downwards continously due to the changes in tubing-diameter. Any closer and more exact explanation would defenitely get you in realm of higher mathematics.
BTW: That also describes the way manufacturing inexactnesses influence the intonation-differences between instruments that otherwise (brand, model, material etc etc) are absolutely identical. So, minor differences where conicalness is tronger or less pronounced make not only false notes come out elsewhere but also the "real" ones. Or what did you guys think why all those so called TOP QUALITY PRO INRTUMENTS tend to look so much alike no matter where they come from...??!
Oli