[78-L] Acoustic recording

[Michael Biel]

From: "DanKj" <MLK402 at verizon.net>
> Many of my instrumental Pathe records sound oddly "backwards" (Sergeant
> Legget cornet solos, especially; is this what we're talking about? (I can
> only describe it as MMahh MMahh MMaah as opposed to Wahh Wahh Wahh)
 

Pathe records are all dubs, so the polarity of the absolute phase is not
necessarily consistent.  What you are hearing is what Clark Johnson has
called "The Wooden Effect" which is the name of a little book he wrote
about it.  Some people are more sensitive to it than others, although he
says that it is a major cause of listening fatigue among people who
can't quite place what is happening.  (I am one of those who do not
consciously notice it.)  Most sounds will have a positive pressure at
the start of notes, but if the absolute phase of the sound is reversed,
the loudspeaker or the diaphragm will start the notes with a negative
pressure with the cone or diaphragm moving backwards instead of
forwards.  If you reverse the speaker connections it would solve it, and
it is something that those who are sensitive to the effect would check
for each record.  Clark gives examples of overdubbed recordings where
the orchestra and the vocalist are at different absolute phasing,
leaving the listener in a quandary as to which way to set it.

Let me make this clear that I am not talking about relative phase
between two stereo channels.  The two speakers must be in the same phase
as each other.  This is matching the phasing of all of the speakers with
the original sound.


Mike Biel  mbiel at mbiel.com