From Wikipedia, the free encyclopedia
A Jecklin Disk is a sound-absorbing disk placed
between two microphones to create an acoustic "shadow" from one
microphone to the other. The resulting two signals can possibly
produce a pleasing stereo effect.
Always, a matching pair of omnidirectional microphones are
used.
The technique was invented by Jorg Jecklin, the former chief
sound engineer of Swiss Radio. He referred to the technique as
an "Optimal Stereo Signal" (OSS). In the beginning Jecklin used
omnidirectional microphones on either side of a 12" disc of
about 3/4" thickness, which had a muffling layer of soft plastic
foam on each side. The capsules of the microphones were above
the surface of the disc just in the center, 16.5 cm apart from
each other and each pointing 20 degrees outside.
Nobody of the users wantetd to notice, that the master found
the 16.5 cm ear spacing between the microphone too narrow and
wrong. Now he tells us in his own papers that the disk has to be
35 cm in diameter and the distance between the microphones have
now to be 36 cm. Really no measures of the distance between the
ears anymore. In loudspeaker stereophony there is no use of the
ear spacing. See Jecklin's paper at:
Jecklin's German from his script: "Zwei Kugelmikrofone sind
mit einem gegenseitigen Abstand von 36 cm angeordnet und durch
eine mit Schaumstoff belegte Scheibe von 35 cm Durchmesser
akustisch getrennt." That means: Two omnidirectional microphones
have a distance from one to another of 36 cm and a separation
between them of a foam plated disk with a diameter of 35 cm.
External links
-
Josephson Microphones - This page has a picture of the old
Jecklin Disk
Categories:
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Wikify from January 2007 |
Microphones |
Sound |
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Audio engineering
