US2784253A

US2784253A - Electro-acoustic transmission system for stereophonic sound phenomena

Info

Publication number: US2784253A
Application number: US255246A
Authority: US
Inventors: Windisch Heinz
Original assignee: Hartford National Bank and Trust Co
Current assignee: Hartford National Bank and Trust Co
Priority date: 1950-12-14
Filing date: 1951-11-07
Publication date: 1957-03-05
Anticipated expiration: 1974-03-05

Description

March 5, 1957 H. WINDISCH 2,784,253

ELECTRO-ACOUSTIC TRANSMISSION SYSTEM FOR STEREOPHONIC SOUND PHENOMENA Filed Nov. 7, 1951 'INVENTOR HEINZ WINDISCH Agent United States Patent ELECTRO-ACOUSTIC TRANSMISSION SYSTEM FOR STEREOPHONIC SOUND PHENOMENA Heinz Windisch, Munich-Grosshadern, Germany, assignor to Hartford National Bank and Trust Company, Hartford, Conn. as trustee Application November 7, 1951, Serial No. 255,246 Claims priority, application Germany December 14, 1950 1 Claim. (Cl. 179-1) In radio transmission engineering the magnetophone is used as a sound recording device. In order to permit the use of stereophony for radio purposes two sound tracks have been recorded on a single band for twochannel transmission with the use of a stereophonic device comprising a double-action reproducing and recording head. Experiments made in thus recording intelligence and music by way of two channels proved that the magnetophone is suitable more particularly for stereophonic records of this kind.

The present invention is based on the recognition that particular results are obtainable by employing two-channel transmission magnetophones in electro-acoustic installations for the transmission of church bell-ringing and the like in such manner that the microphones used for recording the sound phenomena are arranged on both sides of the swinging bell(s) and at least substantially in the direction of motion thereof, two loudspeakers or loudspeaker sets for reproduction being arranged on two opposite sides of the location of the hitherto used bell(s).

The invention permits more particularly to replace the bell(s) at arbitrary locations by apparatus comprising a magnetophone, reproduction amplifiers and loudspeakers. It will be appreciated that a reproducing installation of this type is easily displaceable in contradistinction to heavy bells. In addition, the bell-ringing can be determined at will by a corresponding choice of the bell(s) used in recording and is easily variable by recording a difierent ringing on another band.

In order that the invention may be more clearly understood and readily carried into effect, it will now be described more fully with reference to the accompanying drawing, representing diagrammatically an electro-acoustic transmitting installation according to the invention.

Fig. 1 shows the arrangement of the individual parts of the installation used in the recording bell-ringing. Fig. 2 showing the arrangement used for reproduction.

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As appears from Fig. 1 microphones M1 and M2 are arranged on both sides of the swinging bell G and preferably in the direction of oscillation. In this arrangement now the microphone M1, now the microphone M2 will take up the major part of the sound in accordance with the phase of motion of the swinging bell. The microphone amplifiers are designated V1 and V2, the doubleaction magnetophone being denoted by M. Such a magnetophone comprises in a known manner double-action recording heads by which two sound tracks separated by a neutral zone are recorded simultaneously. By providing corresponding double-action reproducing heads the recorded sound can be reproduced stereophonically through amplifiers V3, V4 and loudspeakers L1, L2 (Fig. 2). The loudspeakers, which may alternatively be replaced by loudspeaker sets, are preferably arranged at opposite sides of the tower T in a direction in which the hitherto used bell(s) oscillate.

Advantageously the loudspeaker sets may, for example, each comprise three loudspeakers having a wide band.

According to the invention it is advisable to use a plurality of double-action magnetophones if particular ringing combinations and carillon playing are to be reproduced.

Fundamentally, two normal magnetophones may be used for the sound recording of both channels. In practice, however, it is difficult to operate both apparatus in step in an adequate manner for stereophony.

What I claim is:

A system for recreating the sound of a bell swinging in a predetermined arcuate path comprising means for separately detecting the sound of said bell at two spaced points on opposite sides of said bell substantially in the plane of said path, means for separately recording the sound detected at each of said two points in separate channels of a sound carrier, means for separately reproducing the sound recorded in said channels, and means for projecting the sound separately reproduced from each of said channels in opposite directions from the reproduction means to thereby audibly create the effect of a swinging bell.

References Cited in the file of this patent UNITED STATES PATENTS Kuniz Ian. 15, 1952