Support for a high fidelity stereophonic system

May 28, 1968 J. MAGYAR ET AL 3,385,929

SUPPORT FOR A HIGH FIDELITY STEREOPHONIC SYSTEM

Filed July 23, 1964 3 Sheets-Sheet 1

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INVENTORY

May 28, 1968

J. MAGYAR ET AL

3,385,929

SUPPORT FOR A HIGH FIDELITY STEREOPHONIC SYSTEM

Filed July 23, 1964

Sheets-Sheet 2

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orrottreys

May 28, 1968

J. MAGYAR ET AL

3,385,929

SUPPORT FOR A HIGH FIDELITY STEREOPHONIC SYSTEM

Filed July 23, 1964

Sheets-Sheet 3

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3,385,929

Patented May 28, 1968

United States Patent Office

2

3,385,929

SUPPORT FOR A HIGH FIDELITY STEREOPHONIC SYSTEM

John Magyar and Richard Houghton Spencer, Toronto, Ontario, Canada, assignors to Clairtone Sound Cor- 5 poration Limited, Rexdale, Ontario, Canada Filed July 23, 1964, Ser. No. 384,607 11 Claims. (CI. 179—1)

ABSTRACT OF THE DISCLOSURE

A high fidelity stereophonic system including a turntable, a pair of speakers and a common support for these components including a column which supports the turntable and also an elongated boom, the speakers being mounted, in practice, on opposite ends of this boom such that vibrations from the speakers are effectively dissipated during travel along the boom to prevent feedback to the turntable unit.

The present invention relates generally to an improved high fidelity stereophonic system, the improvements broadly being concerned with a common support physically integrating the various components of said system, and more specifically with selective regulation of the ²³directional sound radiation of the system to promote an optimum stereophonic effect.

The usual basic components of a high fidelity stereophonic system include a turntable and associated turntable components and a pair of loudspeakers, said com- ³⁰ponents in a usual custom installation being separately housed in individual enclosures which only in rare instances are physically integrated on a common support. By spacially isolating the system components, and more particularly, the low frequency sound loudspeaker from the turntable, the problem of vibration feedback therebetween is obviated. However, but for the vibration feedback problem it unquestionably would be more commercially preferable to have the system components integrated on a common support.

Accordingly, it is broadly an object of the present invention to provide a common support for the individual enclosures of the component parts of a high fidelity stereophonic system which achieves physical integration of said system and which also maintains a spacial relationship ⁴' between said enclosures to a degree which is effective to prevent the transmission of vibration therebetween which adversely affects sound reproduction of the system.

More specifically, it is an object to provide a common support for said various component enclosures which, on the one hand, permits a relatively compact spacial arrangement of said enclosures, and on the other hand offers a sufficiently long path through which vibration can be transmitted therebetween to substantially dissipate _ggmuch of the system vibration.

The present invention is moreover concerned with closely matching the acoustical characteristics of the listening environment to the known characteristics of the recording environment to correspondingly promote a _eQcloser match between the reproduced sound and the original sound. Thus, for example, a musical piece recorded in a cathedral and under usual conditions therein where the performers are hidden and the audience hears only reflected sound waves, is recognized according to the present invention as requiring playback in the listening environment in a manner which duplicates this total indirect transmission of the sound to the listener. Similarly, a musical piece recorded in other environments, as for example in a nightclub, might require playback which transmits the reproduced sound both directly and indirectly to the listener to more closely match the sound transmission of the original recording and listening environments.

Thus, it is a further object of the present invention to provide in a common support for a high fidelity stereophonic system means for mounting the loudspeaker and enclosure assemblies thereon which permits selective adjustment in the directional sound radiation of said loudspeakers to achieve any desired degree of direct and indirect sound transmission.

A common support according to the present invention includes an upstanding hollow column having opposite vertical slots in its upper end accommodating the medial portion of a laterally extending boom. A mounting plate accommodating a turntable enclosure is provided with a 15 cylindrical collar which is slidably disposed in the upper end opening of the column and seats against the boom to secure the same against movement under the weight of the turntable. The loudspeaker enclosures are mounted on the remote ends of the boom in spaced relation from 20 and on opposite sides of the turntable enclosure supported on the column. More particularly, the arrangement of said enclosures on the boom is, on the one hand, compact in that the enclosures at their closest point are not far removed from each other, while on the other hand, the path through which vibration can be transmitted therebetween as determined by the points of connection of said enclosures to said boom is sufficiently long to substantially dissipate much of the vibration of the loudspeakers of the system.

Additionally included within the scope of the present invention are several embodiments of rotatable mountings for the loudspeaker enclosures which permit selective adjustment in the directional sound radiation of the loudspeakers of the system to regulate, as desired, the manner in which the reproduced sound is transmitted to the listener, that is whether directly or indirectly by reflection from surfaces of the listening environment.

The above brief description, as well as further objects, features and advantages of the present invention will be more fully appreciated by reference to the following detailed description of presently preferred, but nonetheless illustrative embodiments in accordance with the present invention, when taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a front elevational view of an assembly of a high fidelity stereophonic system and a common support therefor embodying features of the present invention;

FIG. 2 is a side elevational view of the assembly of FIG. 1;

FIG. 3 is a plan view of the assembly of FIG. 1, as seen from a vantage point beneath the assembly;

FIG. 4 is a partial side sectional view, taken along lines 4—4 of FIG. 1, illustrating on an enlarged scale the mounting of the boom and turntable enclosure support plate on an upstanding column of the support;

FIG. 5 is a partial front sectional view, taken along lines 5—5 of FIG. 4, further illustrating the mounting connection shown in FIG. 4, and additionally the manner in which the electrical wiring is disposed through such connection;

FIG. 6 is an exploded view of FIG. 4 more clearly illustrating the order of assembly of the parts making such connection;

FIG. 7 is an exploded view of FIG. 5, with the electrical wiring removed, and particularly illustrating notches on the boom for seating the same on the column;

FIG. 8 is a detailed isolated view, on an enlarged scale, of a loudspeaker and enclosure assembly with portions of ‘ the enclosure broken away to illustrate one embodiment of a loudspeaker mounting;

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FIG. 9 is a still further enlarged detailed view of the assembly of FIG. 8, with portions thereof in section to illustrate one embodiment of a rotatable boom mounting for said loudspeaker and enclosure assembly;

FIG. 10 is a view similar to FIG. 8 but of another embodiment of a loudspeaker mounting;

FIG. 11 is a plan view, in reduced scale, projected from FIG. 10 as seen from a vantage point beneath the assembly of FIG. 10;

FIG. 12 is an elevational sectional view, taken along lines 12—12 of FIG. 11, of another embodiment of a rotatable boom mounting for a loudspeaker and enclosure assembly; and

FIG. 13 is a plan sectional view, taken on lines 13—13 of FIG. 12, illustrating the cooperating stop pins of such rotatable mounting which limits rotation of said mounting to one 360 degree traverse.

Shown in FIG. 1 is a preferred embodiment of a common support, generally designated 10, for the several component enclosures 12, 14 of a high fidelity stereophonic system. The relatively large generally rectangular enclosure 12 will be understood in practice to house not only the turntable of the system, but also the amplifier ^and other such component parts of the system, but for simplicity s sake will herein be considered as principally an enclosure for the turntable (not shown) of the system. The generally spherical enclosures 14 each house a loudspeaker of the system. As shown in FIG. 1, the enclosures 12, 14 are relatively compactly arranged on the support 10, each of the loudspeaker enclosures 14 being spaced at their closest point only a comparatively small distance D from the opposite ends of the turntable enclosure 12. However, while achieving this desirable compact spacial arrangement, it will be noted that the path through which vibration of a loudspeaker could be transmitted to the turntable of the system, taking for example the left hand loudspeaker enclosure 14 relative to the turntable enclosure 12, is determined by the respective points of contact A and B of these enclosures with the common support 10 and thus is several times the distance D. Accordingly, the common support 10 of the present invention which permits, on the one hand, such a compact spacial arrangement of. the enclosures 12, 14 while, on the other hand, maintaining a comparatively long vibration path between said enclosures represents an optimum solution to obviating vibrational feedback between the component parts of the system consistent with an economy of space.

As shown in FIG. 1, the common support 10 includes a hollow cylindrical column 16 supported in a vertical upright position on a wide leg base 18 suitably connected to the base of the column. As is best shown in FIGS. 4-7, the upper end 20 of the column is provided with opposite vertical slots 22 for accommodating an elongated horizontally disposed boom 24 (see FIGS. 1, 2) and also cylindrical extending collar 26 welded to the underside of a mounting plate 28 for the turntable enclosure 12. In order of assembly, the medial portion 30 of the boom 24 is first slidably disposed in the slots 22 such that spaced notches 32 provided on the underside of said boom engage the bottom surfaces 34 of the said slots for generally seating the boom 24 within the column 10. Following this, the mounting plate collar 26 is slidably disposed in the end opening 36 of the column 10 and seats against the upper surface 38 of the boom, this sliding connection between the collar 26 and column 10 being secured against rotation by the engagement of the upper end of each slot 22 with spaced blocks 40 welded to the outer periphery of the collar 26. To further prevent rotation of the collar 26 within the column 10 and also to interconnect the collar 26 and boom 24, the length provided the collar is such as to project the lower collar end. 42 beyond the upper boom surface 38 and such projecting collar end is provided with seating slots 44 engaging this surface portion of the boom. Moreover, not only is it provided that the collar 26 seat against the 75 boom 24 as just described, but also that the supported weight of the turntable and other components (not shown) which in practice are housed in the enclosure 12 and mounted on the plate 28 bear against the boom 24 to securely hold this support member in its mounted position on the upright column 10. This is achieved by providing the upper portion 46 of the mounting plate collar 28 from the seating slots 44 to the connection of the mounting plate 28 thereon with sufficient length to clear the upper end of the column 10 when said collar is telescoped in said column, such clearance being exaggerated in FIG. 4 and designated C. Due to the weight of the enclosure 12 bearing against and firmly holding the boom 24 at its medial portion 30 in position within the column 10, there is no problem in providing sufficient length to the boom 24 so that the overhang of this member on either side of the column 10 is adequate to project the opposite ends 48 of said boom sufficiently beyond the ends of the enclosure 12 to accommodate the loudspeaker enclosures 14 thereon. Moreover, since the enclosure 12 as best shown in FIG. 1 is mounted with considerable overhang on the mounting plate 28, a pair of spaced brackets 50 are bolted on the underside of said enclosure, as shown in FIG. 3, and are seated on the boom overhang to stabilize the mounted position of the enclosure 12 on the support 10.

Returning to FIG. 5, it will be seen that the loudspeaker electrical wiring 52 is directed from the components housed in the enclosure 12 (not shown in FIG 5) through aligned openings 54 and 56 in the mounting plate and boom 28, 24 respectively, to a channel 58 machined in the underside of the boom 24, and as best shown in FIG. 3, is then directed to each of the loudspeaker enclosures 14 for connection to said loudspeakers as is hereinafter described.

In accordance with the present invention, the loudspeaker enclosures 14 are each mounted on a boom end 48, the mounting connection therebetween being such as to permit rotation of said enclosures 14 for selective adjustment of the directional sound radiation of the system for the purpose of matching the sound transmission in the listening environment to the known sound transmission of the original recording environment. Thus, where it is known that the musical piece is recorded in for example a cathedral and under usual conditions where the performers are hidden and the audience hears only reflected sound waves, the loudspeaker enclosures 14 are correspondingly orientated in their rotatable mountings to transmit the sound by reflection from surfaces within the listening environment to duplicate this total indirect transmission of the sound to the listener.

One preferred embodiment of a rotatable mounting tor each of the loudspeaker enclosures is shown in FIGS 8 and 9 and generally designated 60. Mounting 60 includes a spindle 62 provided with a machined slot 64 which slidably receives the boom end 48. After being thusly fitted on the boom end 48, the spindle 62 is physically joined to said boom by a bolt 66 which is conveniently extended from the underside of and through the body of the boom in the working clearance C of the channel 58 into the body portion of said spindle 62 which extends inwardly of the end of the boom 24. Disposed in a vertical central through bore 68 provided in the body of the spindle 62 is a hollow threaded stud 70 which interconnects the loudspeaker enclosure 14 and the spindle 62 and also serves as a vertical axis of rotation for the mounting 60.

As is best shown in FIG. 9, seated in an upper end counterbore 72 of the through bore 68 and about the stud 70 is a stationary plastic bearing block 74 which presents a conical seating surface 76 to a similarly shaped conical surface 78 of a rotatable bearing member 80 also disposed about the stud 70 and in practice seated in saul bearing block. By providing the bearing members 74, 80 with confronting conical bearing surfaces 76, 78,

3,385,929 5 6 mounting a particular lip 138 which in the assembly of the enclosure 14' accommodates the conical speaker baffle 104' in a sliding force fit. More particularly, the end of the speaker baffle 104' fitted on the bottom shell half 5 96' is provided with contiguous walls 140 and 142 of varying diameters, the larger diameter wall 140 being the one force fit on the circular lip 138 of the bottom shell half 96'. Additionally, plural perforated top shell halves 144 and 146 are employed in this speaker en1Q closure embodiment, the perforations of which when mounted on the bottom shell half 96' are out of alignment with each other to make the interior of the enclosure 14 less accessible to the passage of dirt particles and to outside probing.

In order of assembly, the wall 140 of the speaker baffle 104' is force fit first about the lip extension 138 of the bottom shell half 96' and the perforated inner top shell half 146 disposed over said baffle in a force fit with the baffle wall 140. The construction of the spherical enclo20 sure 14' is then completed by disposing the perforated outer top shell half 144 in a force fit over the baffle wall 142. Incorporated in the construction of the loudspeaker enclosure 14' to promote richer acoustical characteristics in the reproduced sound is a relatively hard acoustical material 148 lining the inner surface of said enclosure and backed with a lining of softer acoustical material 150.

From the foregoing description it will be appreciated that the common support 10 of the present invention represents an optimum solution to the vibration feed back 30 problem usually encountered in the operation of a high fidelity stereophonic system in that the various enclosures 12, 14 (and 14') for the component parts of said system are mounted in a relatively compact spacial arrangement on said support, while the comparatively longer path 35 through which vibration can be transmitted between said enclosures is maintained at a length which for all practical purposes results in substantial dampening out of said vibration. Additionally, the loudspeaker enclosures 14, 14' are supported on said common support 10 on ro40 tatable mountings 60, 60' which permit selective adjustment of the directional sound radiation of the system.

A latitude of modification, change and substitution is intended in the foregoing disclosure and in some instances some features of the invention will be employed without _4g a corresponding use of other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the spirit and scope of the invention herein.