Brass Acoustics info - sound production, resonance, etc.

[JayKosta]

This article includes good information about the basic physics of sound production of brass instruments - see chapter 3.

https://www.tnt-audio.com/casse/study_of_french_horn_harmonics.pdf

It discusses: basics of sound production, resonance, harmonics, impedance, standing wave, etc.

Much of the article is about French horn, but the acoustics section applies to all brass instruments.

This is from the beginning of the acoustics section -

" A pulse of air is introduced to the end of a pipe from the player via the lips, which produces a pressure wave travelling at the speed of sound. The wave impedance in the pipe is relatively high compared with the atmosphere, and when the wave reaches the end it suddenly meets a low impedance. As a result of this impedance mismatch a proportion of the wave will be reflected and will travel back down the pipe. The non-reflected portion of the wave travels out of the pipe and produces the sound that we hear."
_________________
Most Important Note ? - the next one !
KNOW (see) what the next note is BEFORE you have to play it.
PLAY the next note 'on time' and 'in rhythm'.
Oh ya, watch the conductor - they set what is 'on time'.

[kevinh8swriting]

Is this why bigger bell = louder? The bigger bell usually entails more flare, which means by the end of the pipe the impedance mismatch at the end of the horn will be less than it would be if the bell were smaller. That in turn would mean that less of the wave is reflected back into the horn, or, to put it different, more of the wave is projected out into the room.

[mograph]