Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

Re: Sound Cancellation



Hi,

One additional comment on cancellation. I
suspect much of the confusion in this arises from
the use of idealized cases. Consider the organ
pipe. We never discuss that it is not a true
standing wave. Energy is being lost by the pipe
and contained air system. The nodes are not
points of zero amplitude because the the two
counterpropagating waves are not of the same
amplitude. Energy is lost at the reflection. (If
you have a full set of microwave stuff with wave
guides and a standing wave ratio meter and
associated wave guide with a moveable detector it
is easy to see this.) We also almost never
discuss the transition from no sound to an
established standing wave in an organ pipe.

Thanks
Roger