US3590942A - Omnidirectional loudspeaker system - Google Patents

Omnidirectional loudspeaker system Download PDF

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Publication number
US3590942A
US3590942A US884830A US3590942DA US3590942A US 3590942 A US3590942 A US 3590942A US 884830 A US884830 A US 884830A US 3590942D A US3590942D A US 3590942DA US 3590942 A US3590942 A US 3590942A
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United States
Prior art keywords
loudspeakers
loudspeaker
frequency
audiofrequency
housing
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Expired - Lifetime
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US884830A
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English (en)
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Peter Globa
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H H SCOTT Inc
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H H SCOTT Inc
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS
    • H04R1/00—Details of transducers, loudspeakers or microphones
    • H04R1/20—Arrangements for obtaining desired frequency or directional characteristics
    • H04R1/32—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS
    • H04R1/00—Details of transducers, loudspeakers or microphones
    • H04R1/20—Arrangements for obtaining desired frequency or directional characteristics
    • H04R1/32—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only
    • H04R1/323—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only for loudspeakers

Definitions

  • the present disclosure relates to a quadranttype loudspeaker particularly adapted for the audiofrequency band, having a pair of opposing low-band speakers mounted at different distances from the floor or other resting surface for the loudspeaker system and a plurality of asymmetrically mounted high-, and in some cases, mid-frequency speakers.
  • the present invention relates to loudspeaker systems, being more particularly directed to the so-called quadrant type of loudspeaker systems in which speakers or speaker assemblies are positioned indifferent quadrants and wherein the overall sound radiation pattern in the bands of interest is adjusted to be substantially uniform in all directions, or at least to provide what, to the listener, appears to' be substantially uniform sound quality and amplitude in such omnidirections.
  • Free-standing quadrant speakers and the like differ in their characteristics from ordinary speakers contained in housings and the like that are adapted to be set next to a wall or put into a bookcase or located on a shelf or proximal to other surfaces in a room. While such speakers have heretofore been used in spaced pairs for the reproduction of stereophonic sound, they inherently carry with them the limitation that the listener must be within a relatively restricted angle in front of the speakers.
  • a further object is to provide a new and improved loudspeaker system of more general utility as well.
  • the invention contemplates a substantially omnidirectional quadrant loudspeaker system for the audiofrequency band comprising a four-sided housing, mounting substantially centrally in each of a pair of opposing sides thereof substantially similar low audiofrequency loudspeakers, one mounted with its center approximately a quarter of the midwavelength of the low audiofrequency band above the bottom or the housing and the other mounted substantially three-eighths of said wavelength above the said bottom, and a plurality of high audiofrequency loudspeakers at least one asymmetrically mounted off center in a comer of each side of the housingnear the top thereof.
  • Preferred constructional details are hereinafter set forth.
  • FIG. 1 of which is an isometric view showing a speaker assembly constructed in accordance with the preferred embodiment of the invention
  • FIG. 2 is a cross section of the lower portion of FIG. 1;
  • FIG. 3 is a similar view of a modification.
  • a four-sided housing is illustrated at l, illustrated for purposes of explanation in the preferred, though not essential, form of a prismatic housing having pairs of opposing sides 2, 2' and 4 and 4'.
  • a low audiofrequency loudspeaker in the range up to about 1 kHz. is mounted as shown at 3 in the side 2, very close to the bottom surface 5 of the housing 1, which may rest, for example, upon the floor or other surface.
  • the center of thespeaker 3 is preferably located above said bottom surface approximately one-quarter of the mean wavelength of the low-frequency portion of the audiofrequency band; say one-quarter of about 500 Hz. (approximately 6% inches).
  • a substantially identical low-frequency speaker 3 is similarly mounted, except that, in accordance with the invention, it is located somewhat higher from the bottom 5 of the housing 1, namely, the order of three-eighths of the aforementioned wavelength, or approximately 9 /4 inches.
  • High frequency loudspeakers (approximately in the range of 5 kHz.) are respectively shown at 6 and 6, mounted in the upper left-hand corners of the respective sides 2 and 2' near the top thereof, asymmetrically off center, for reasons later explained.'Similarly positioned asymmetrical similar high-frequency loudspeakers are shown at 6" and 6" located in sides 4' and 4, respectively.
  • the system I may be used for monophonic, omnidirectional quadrant purposes, or as shown in FIG. 1, for stereophonic purposes together with an identical unit 1' spaced therefrom as shown in dotted lines.
  • the high frequency loudspeakers 6, 6', 6" and 6" are in individual small enclosures to prevent low frequency acoustic signals existing within the housing 1 from reaching the diaphragms and thereby causing distortion. These individual enclosures contain damping material to attenuate whatever resonances might exist within these high frequency loudspeakers. All high frequency loudspeakers are connected in series-parallel arrangement to the high frequency output terminals of the frequency-dividing crossover network (not shown) which receives electrical signals from the amplifier. The high frequency loudspeakers 3 and 3' share the common volume of the housing I and are connected in parallel to the high frequency output terminals of the frequency-dividing crossover network connected to the amplifier (not shown).
  • the housing 1 is filled with damping material for reasonshereinafter explained.
  • FIG. 2 a cross-sectional diagram of the arrangement of FIG. 1 is shown with sides 2 and 2' being illustrated in cross section and containing loudspeakers 3 and 3'.
  • These loudspeakers have diaphragms 8 and 8' which create the acoustical waves emanating from loudspeakers 3 and 3', with the effective centers of acoustic radiation being at points C and c, different distances D and D above the bottom surface 10, as later discussed.
  • theoriginal source C and the image source C would operate in phase to create, at low frequencies, aidoubling of. acoustic sound pressure over that created by source C alone.
  • the delay in arrival of the sound from sources C and C-' at the listener's ear, obviously located outside the enclosure l and above the floor 10 will add up vectorially and, at some particular frequencies, the effective output of sources C and C" will cancel one another.
  • this cancellation will take place at odd multiples of the frequency where the sum of distances D and D" is equal to one-half wavelength of the sound in the air.
  • the acoustic waves emanating from source C and from source C will also arrive at the listener's car at diflerent times, since they are required to travel around the outside of the enclosure 1 and may therefore undergo a different amount of delay'depending upon the relative distance from the two sources C and C, as measured from the listeners car.
  • the same analysis also holds for-the source pairs C and C', C and C"and Cand C"'.
  • the distance D were selected to be equal to distance D and if the loudspeakers were set apart by a distance D"" equal again to distance D, all the sources and'their images,
  • loudspeakers 3 and 3 shareia common volume within enclosure 1, the deleterious effects of direct coupling between loudspeakers 3 and 3' must also be counteracted.
  • customary in loudspeaker design to provide within the enclosure a certain amount of sound-absorbing or damping material which minimizes undesired reflections of sound from the interior walls of the enclosure reacting back on the radiating diaphragm of a loudspeaker.
  • the acoustic waves emanating from one loudspeaker must be prevented from causing undesirable effects'at any other loudspeaker.
  • the loudspeakers with their effective sources C and C operate in phase, and the sound from one loudspeaker arrives at the other essentially in phase, and is essentially in phase within the whole enclosure 1.
  • Enclosure 1 thus effectively acts as an acoustic capacitor providing an acoustic stiffness.
  • the sound emanating from one loudspeaker diaphragm arrives at the other with some delay and at still different delays to all the interior surfaces of the enclosure 1. If no damping material were provided, these delays would be equal to the distance between the loudspeakers and their now interior images, divided by the speed of sound in air. Normally, in air, sound waves cause the air to expand and to compress, following the adiabatic curves.
  • this damping material maintains the instantaneous temperature of the air at the same point because of its large thermal capacity compared to air, and the instantaneous sound waves and pressure excursions follow the equal temperature or isothermal curves.
  • This changes the speed of sound to a lower value approximately equal to one divided by the fourth root of two, or 1.22. Consequently, referring back to air withoutsound-absorbing material, the effective distance between radiating centers C and C has been lengthened by the fourth root of two, and interior cancellations and reinforcements, as compared to outside distances, have been shifted into a new frequency range by that ratio, further improving the regularity of frequency response.
  • FIG. 3 shows a modification of the loudspeaker system of FIG. 1, involving three groups of loudspeakers.
  • Loudspeakers 3 and 3' are intended to cover the low frequency region typically encompassing the frequency range between 40 Hz. and 1,000 Hz. or less.
  • Midfrequency loudspeakers marked 16, 16', 16'', and 16" cover the frequency region between approximately 1,000 Hz or lower, up to 4,000 or 5,000 Hz.
  • High frequency loudspeakers 6, 6, 6", and 6" cover the frequency region higher than that covered by the midfrequeneyj loudspeakers.
  • the high-frequency loudspeakers are of the same nature as those of FIG. 1 and are again mounted in a similar arrangement on the four surfaces of the enclosure.
  • Midfrequency loudspeakers 16 through 16" each have their own acoustic enclosures mounted in the back of the diaphragms to prevent direct undesired coupling to each other and coupling to and from the low frequency loudspeakers 3 and 3.
  • loudspeakers 16 through 16" have been mounted asymmetrically with respect to the vertical axis of panels 2 and 2', and 4 and 4.
  • loudspeakers l6 and 16" are mounted at differing elevations with respect to the floor. Since, in the frequency range to be covered by the midfrequency loudspeakers, the dimensions of the enclosure are comparable or larger than a full wavelength at the lowest frequency covered by the midfrequency loudspeakers, it is only necessary that adjacent loudspeaker pairs be mounted at different elevations. Midfrequency loudspeakers l6 and 16 mounted on surfaces 2 and 2' are therefore mounted at a higher elevation than midfrequency loudspeakers 16" and 16" in respective surfaces 4' and 4. By this means, irregularities in frequency response due to radiation from all loudspeaker systems are minimized.
  • loudspeaker drivers 3 and 3 are connected in parallel to the low-frequency output of the electrical crossover network connected to the amplifier.
  • Loudspeakers l6, 16', I6" and 16" are connected in a series-parallel arrangement to the midfrequency output of the crossover network, and high frequency loudspeakers 6, 6', 6" and 6" are connected in a series-parallel arrangement to the high frequency terminals of this frequency-dividing crossover network as is well known.
  • loudspeaker systems of the reflective type in the prior art can give a satisfactory illusion of presence and depth when listening to stereophonic program material
  • these loudspeaker systems all employ loudspeaker drivers of identical design and, for good listening .quality, require an additional electronic equalizer. This, in turn, substantially increases the required amplifier power for equal sound pressure such that these loudspeaker systems are a complex and expensive approach to achieve good quality listening.
  • the omnidirectional loudspeaker of the present invention represents a no-compromise design. These loudspeakers can be placed virtually anywhere within the room, giving extraordinarily good wide-range response and stereophonic realism and presence throughout the room. No additional equalizers or special amplifiers, moreover, are required.
  • a substantially omniquadrant loudspeaker system for the audiofrequency band that comprises a four-sided housing mounting substantially centrally in each of a pair of opposing sides of the housing substantially similar opposing low-audiofrequency loudspeakers, one mounted with its center about one-quarter the wavelength of the mean of the low audiofrequencies above the bottom of the housing and the other mounted thereabove about three-eighths said mean wavelength, and a plurality of high-audiofrequency loudspeakers, at least one asymmetrically mounted off center in each side of the housing near corners at the top thereof.
  • a loudspeaker system as claimed in claim 1 provided with damping material packed directly between the opposing lowaudiofrequency loudspeakers.

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  • Health & Medical Sciences (AREA)
  • Otolaryngology (AREA)
  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Obtaining Desirable Characteristics In Audible-Bandwidth Transducers (AREA)
  • Circuit For Audible Band Transducer (AREA)
US884830A 1969-12-15 1969-12-15 Omnidirectional loudspeaker system Expired - Lifetime US3590942A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US88483069A 1969-12-15 1969-12-15

Publications (1)

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US3590942A true US3590942A (en) 1971-07-06

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ID=25385503

Family Applications (1)

Application Number Title Priority Date Filing Date
US884830A Expired - Lifetime US3590942A (en) 1969-12-15 1969-12-15 Omnidirectional loudspeaker system

Country Status (7)

Country Link
US (1) US3590942A (fr)
AU (1) AU1588270A (fr)
BE (1) BE749737A (fr)
DE (1) DE2045610A1 (fr)
FR (1) FR2068810B3 (fr)
GB (1) GB1269005A (fr)
NL (1) NL7012554A (fr)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3720787A (en) * 1970-03-28 1973-03-13 Victor Company Of Japan Omni-directional globular speaker system
US3727004A (en) * 1967-12-04 1973-04-10 Bose Corp Loudspeaker system
US3818138A (en) * 1971-07-26 1974-06-18 A Sperrazza Barrel shaped speaker enclosure
US3923123A (en) * 1972-11-10 1975-12-02 Latimer Sayer Laurence Sound reproducing apparatus
US4006308A (en) * 1974-07-25 1977-02-01 Karl Otto Ponsgen Loudspeaker arrangement
USRE31228E (en) * 1967-12-04 1983-05-03 Bose Corporation Loudspeaker system
WO1991015934A1 (fr) * 1988-10-11 1991-10-17 Robert Jurrien Oliemuller Coffret pour haut-parleurs
FR2668015A1 (fr) * 1990-10-16 1992-04-17 Piccfaluga Pierre Procede pour ameliorer la qualite de la restitution d'une ambiance sonore, et appareil de mise en óoeuvre comportant au moins un haut-parleur emettant dans trois directions.
US5268538A (en) * 1991-06-12 1993-12-07 Sonic Systems, Inc. Hemispherically wide-radiating-angle loudspeaker system
US20100246880A1 (en) * 2009-03-30 2010-09-30 Oxford J Craig Method and apparatus for enhanced stimulation of the limbic auditory response
US8175304B1 (en) * 2008-02-12 2012-05-08 North Donald J Compact loudspeaker system
US20140321692A1 (en) * 2011-10-04 2014-10-30 Zoltan Bay Loudspeaker

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3268030A (en) * 1965-04-13 1966-08-23 Finn H Magnus Acoustic system
US3360072A (en) * 1962-10-12 1967-12-26 Carlsson Stig Sound reproducing apparatus
US3393764A (en) * 1966-12-27 1968-07-23 Curtiss R. Schafer Loudspeaker systems

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3360072A (en) * 1962-10-12 1967-12-26 Carlsson Stig Sound reproducing apparatus
US3268030A (en) * 1965-04-13 1966-08-23 Finn H Magnus Acoustic system
US3393764A (en) * 1966-12-27 1968-07-23 Curtiss R. Schafer Loudspeaker systems

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3727004A (en) * 1967-12-04 1973-04-10 Bose Corp Loudspeaker system
USRE31228E (en) * 1967-12-04 1983-05-03 Bose Corporation Loudspeaker system
US3720787A (en) * 1970-03-28 1973-03-13 Victor Company Of Japan Omni-directional globular speaker system
US3818138A (en) * 1971-07-26 1974-06-18 A Sperrazza Barrel shaped speaker enclosure
US3923123A (en) * 1972-11-10 1975-12-02 Latimer Sayer Laurence Sound reproducing apparatus
US4006308A (en) * 1974-07-25 1977-02-01 Karl Otto Ponsgen Loudspeaker arrangement
WO1991015934A1 (fr) * 1988-10-11 1991-10-17 Robert Jurrien Oliemuller Coffret pour haut-parleurs
WO1992007448A1 (fr) * 1990-10-16 1992-04-30 Pierre Piccaluga Procede pour ameliorer la qualite de la restitution d'une ambiance sonore, et appareil de mise en ×uvre comportant au moins un haut-parleur emettant dans trois directions
FR2668015A1 (fr) * 1990-10-16 1992-04-17 Piccfaluga Pierre Procede pour ameliorer la qualite de la restitution d'une ambiance sonore, et appareil de mise en óoeuvre comportant au moins un haut-parleur emettant dans trois directions.
US5446793A (en) * 1990-10-16 1995-08-29 Piccaluga; Pierre Method of improving the quality of sound reproduction and apparatus for carrying at least one loudspeaker emitting in three directions
US5268538A (en) * 1991-06-12 1993-12-07 Sonic Systems, Inc. Hemispherically wide-radiating-angle loudspeaker system
US8175304B1 (en) * 2008-02-12 2012-05-08 North Donald J Compact loudspeaker system
US20100246880A1 (en) * 2009-03-30 2010-09-30 Oxford J Craig Method and apparatus for enhanced stimulation of the limbic auditory response
US20110245585A1 (en) * 2009-03-30 2011-10-06 Oxford J Craig Method and apparatus for enhanced stimulation of the limbic auditory response
US9392357B2 (en) * 2009-03-30 2016-07-12 J. Craig Oxford Method and apparatus for enhanced stimulation of the limbic auditory response
US20140321692A1 (en) * 2011-10-04 2014-10-30 Zoltan Bay Loudspeaker
US9088849B2 (en) * 2011-10-04 2015-07-21 Zoltan Bay Loudspeaker

Also Published As

Publication number Publication date
DE2045610A1 (de) 1971-06-24
AU1588270A (en) 1971-12-09
FR2068810A7 (fr) 1971-09-03
FR2068810B3 (fr) 1973-08-10
NL7012554A (fr) 1971-06-17
BE749737A (fr) 1970-10-01
GB1269005A (en) 1972-03-29

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