Re: Mixing it...

Subject: Re: Mixing it...
From: Charlie Richmond (
Date: Mon May 24 1999 - 12:53:55 EDT

On Mon, 24 May 1999, KEVIN AUSTIN wrote:

> About 6 minutes before the train arrived, we heard the first, very distant
> whistle, followed by, what appeared to be a very faint echo. It appeared
> to be continuously descending in pitch. Shortly after (since the train was

This would be a result of the train slowing down.... Doppler says that
the pitch will be higher than normal as objects approach each other and
lower as they separate.

> approaching), the horn sounded again, this time with a longer echo, and a
> very clear echo, with the pitch slowly descending. A third time, the horn
> sounded, closer yet, the echo lasted more than ten seconds, with a
> descending pitch shift throughout.

All of this is consistent with the train slowing down - the pitch would
gradually reduce from the higher pitch resulting from the train moving at
a high speed toward you down to the normal pitch as it stopped.

> About 1 minute after the train left the station, the horn blew again --
> with echo. This time, the glissando on the horn was ascending.

Yep.... as the train left the station, it increased in speed and the pitch
rose again from normal toward the higher pitch resulting from two object
moving toward each other...

> It took a couple of days to think this one out. It was ... but that would
> be giving it away ... any solutions?

Sounds normal to me as long as the train was always moving toward you....
If it was moving away during any of this, you've got a problem.... ;-)


+-------- ---------+
"Lo, thus, by day my limbs, by night my mind
 For thee, and for myself, no quiet find." - Sonnet XXVII

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