sound of a trumpet
RichD wrote:
This is what I don't get.
How do you get a reflection from the open end?
I can't picture that. It doesn't jibe with my (fading)
memory of studying transmission lines, in EM,
where you get standing waves, with a termination
at each end.
No, you DON'T get standing waves with a termination at each end.
If you short the end of the cable, you get an inverted reflection back.
If you leave the end of the cable open, you get a non-inverted reflection
back.
ONLY if the cable is terminated into an impedance equal to the characteristic
impedance of the line do you not get a reflection; the termination load
appears like additional cable and the signal goes quietly into it as if it
were so.
The same thing happens with an open or closed organ pipe and creates the
internal resonance of the pipe.
In a trumpet it gets interesting.... because the bell of a trumpet is
effectively an impedance-matching transformer....
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
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