Electrocoustic pipes for electronic organs

Claim 2

In an electroacoustic transducing system for transducing tone signals generated by an electronic organ within a structure having a sound reflecting ceiling surface, said electronic organ having provision for generating in separate leads tone signals corresponding with different tone colors, the combination of an elongated hollow internally sound reflecting tube having its longitudinal axis vertical and its lower end totally closed, said hollow tube having a depth to width ratio greater than 4 to 1 and having a longitudinal axis; a loudspeaker having a sound radiator, said sound radiator having a sound radiating area substantially equal to the cross sectional area of said tube and said loudspeaker being mounted at the upper end of said hollow tube so as to radiate directly upwardly toward said sound reflecting surface, said sound radiator having a sound radiating area designed to radiate the lowermost frequencies oF a selected one of said stops essentially omnidirectionally and the highest notes of said one of said stops only upwardly along said axis for reflection downwardly by said reflecting ceiling surface, said hollow tube including acoustic absorbing material in its bottom for damping acoustic reflections from said lower end, said hollow tube including at least one internal discrete narrow acoustic absorbing ring secured to the inner surface of said tube and located to damp only relatively few selected frequencies of said tone color which might otherwise occur at levels not appropriate to said selected tone color, said tube being acoustically rigid and having a volume selected to resonate as a Helmholtz resonator near the lowest frequency of said selected one of said stops.

Claim 3

The combination according to claim 1, wherein said hollow member has a substantially rectangular radiative port near its lower end, said port being sized to resonate with the volume of the hollow member at a frequency near the low-frequency limit of the range of said signals.

Claim 4

The combination according to claim 1, wherein said first mentioned acoustic absorbing material is a substantially conically-tapered hollow in a mass of sound-absorbent material, said hollow having its apex at said closed end.

Claim 5

The combination according to claim 2, wherein said port extends at least at its upper side into a lip opening in said tube sized for tuning said tube, said lip opening being covered with an acoustically transparent covering material which visually obscures said lip opening.

Claim 6

The combination according to claim 2, wherein said system includes: a supporting sleeve member for said tube at least partially surrounding said tube only at its lower end, there being a V-shaped opening in said sleeve member under said port, said V-shaped opening having its apex extending downwardly and having its base at least as wide as said port, the configuration of said tube, said V-shaped opening and said port being such as to simulate a pipe of a pipe organ.

Claim 7

The combination according to claim 2, wherein said hollow member contains in the lower end thereof a conically tapered hollow in a mass of sound-absorbent material, the apex of said hollow being the lowermost point of said mass.

Claim 8

The combination according to claim 6, wherein said tube contains at least one narrow ring of sound-absorbent material located between the upper end of said hollow member and said port, said ring being positioned to damp only relatively few selected frequencies of said tone color which might otherwise occur at levels not appropriate to the selected stop.

Claim 9

A tone cabinet for an electronic organ, comprising in combination: a main box-like enclosure, at least one row of electroacoustic pipes extending upward from the top of said enclosure, at least a first relatively-large loudspeaker facing outward from one side of the main enclosure, at least a second relatively-large loudspeaker facing outward from the other side of said main enclosure and a multi-channel electronic amplifier for separately supplying amplified organ tone signals via separate channels of each amplifier to each of said loudspeakers, electroacoustic pipes provided on a per stop basis, wherein each of said electroacoustic pipes comprises in combination: an elongated hollow member having a sound reflective interior and having a length-to-width ratio of the order of 7 to 1, a further loudspeaker mounted at the top of each of said hollow members with its front radiating surface directed upwardly, said loudspeakers having each a radiating area which is minimum for effective radiation of the frequencies of the stop to be radiated by that loudspeaker and said pipes having the cross sectional area of the loudspeaker supported thereby, means for damping reflection of acoustic waves from the bottoms of each of said hollow members, and further means for damping out partials which absent said further means would radiate at inappropriate amplitudes, and means for connecting said further loudspeakers to separate channels of said multichannel electronic amplifier.

Claim 10

A tone cabinet for an electronic organ, comprising in combination: a main box-like enclosure, at least one row of electroacoustic pipes extending upward from the top of said enclosure, at least a first relatively-large loudspeaker facing outward from one side of the main enclosure, at least a second relatively-large loudspeaker facing outward from the other side of said main enclosure and a multi-channel electronic amplifier for separately supplying amplified organ tone signals via separate channels of each amplifier to each of said loudspeakers, electroacoustic pipes provided on a per stop basis, wherein each of said electroacoustic pipes comprises in combination: an elongated hollow member having a sound reflective interior and having a length-to-width ratio of the order of 7 to 1, a further loudspeaker mounted at the top of each of said hollow members with its front radiating surface directed upwardly, said loudspeakers having each a radiating area which is minimum for effective radiation of the frequencies of the stop to be radiated by that loudspeaker and said pipes having the cross sectional area of the loudspeaker supported thereby, means for damping reflection of acoustic waves from the bottoms of each of said hollow members, and further means for damping out partials which absent said further means would radiate at inappropriate amplitudes, and means for connecting said further loudspeakers to separate channels of said multichannel electronic amplifier.

Claim 11

The combination according to claim 8, wherein said main enclosure contains: a third relatively-large loudspeaker facing outward from said one side of said main enclosure, a fourth relatively-large loudspeaker facing outward from said other side of said main enclosure and a plurality of smaller enclosures, one for each of said first and second loudspeakers and one for said third and fourth loudspeakers.

Claim 12

In an acoustic radiation system for an electronic organ comprising an array of acoustic radiators arranged to visually simulate the pipes of a pipe organ, said acoustic radiators being located in a room having an acoustically reflective ceiling located above said radiators and a plurality of seats facing said radiators, the combination wherein each of said acoustic radiators includes a vertical hollow pipe having its lower end closed and its upper end terminated by a loudspeaker, said loudspeaker being arranged to radiate vertically upwardly toward said ceiling, said loudspeaker and said pipe having substantially the same transverse areas, a separate source of multi-partial tone signals corresponding with a stop of said organ and comprising plural frequencies of the musical scale having partials appropriate to said stop coupled to drive each of said loudspeakers, respectively, each of said loudspeakers having a radiative area selected to effectively radiate the lowermost frequencies of said tone signals applied to that loudspeaker, each of said hollow pipes being arranged to provide an enclosure for its associated loudspeaker which by virtue of its internal volume and construction is resonant near said lowermost frequencies of said tone signals and contains substantially no internal acoustic standing wave patterns at said lowermost frequencies, whereby different partials of said tone signals produce diverse acoustic radiation patterns, the higher partials radiating directionally only toward said ceiling and the lower partials radiating toward said ceiling and also in azimuth, said seats being located at levels near the levels of the lower ends of said pipes and well below the levels of said loudspeakers.

Claim 13

In an acoustic radiation system for an electronic organ comprising an array of acoustic radiators arranged to visually simulate the pipes of a pipe organ, said acoustic radiators being located in a room having an acoustically reflective ceiling located above said radiators and a plurality of seats facing said radiators, the combination wherein each of said acoustic radiators includes a vertical hollow pipe having its lower end closed and its upper end terminated by a loudspeaker, said loudspeaker being arranged to radiate vertically upwardly toward said ceiling, said loudspeaker and said pipe having substantially the same transverse areas, a separate source of multi-partial tone signals corresponding with a stop of said organ and comprising plural frequencies of the musical scale having partials appropriate to said stop coupled to drive each of said loudspeakers, respectively, each of said loudspeakers having a radiative area selected to effectively radiate the lowermost frequencies of said tone signals applied to that loudspeaker, each of said hollow pipes being arranged to provide an enclosure for its associated loudspeaker which by virtue of its internal volume and construction is resonant near said lowermost frequencies of said tone signals and contains substantially no internal acoustic standing wave patterns at said lowermost frequencies, whereby different partials of said tone signals produce diverse acoustic radiation patterns, the higher partials radiating directionally only toward said ceiling and the lower partials radiating toward said ceiling and also in azimuth, said seats being located at levels near the levels of the lower ends of said pipes and well below the levels of said loudspeakers.

Claim 14

In an electronic organ system, said electronic organ system including an electronic organ providing tone signals pertaining to separate stops of said organ on separate leads, the combination comprising a plurality of vertical hollow tubes, one for each of said stops, a loudspeaker providing a vertically upward radiation pattern secured only at the upper end of each of said tubes, means totally closing the lower end of each of said tubes, acoustic damping means located in the bottom of each of said tubes for damping reflections of acoustic waves upwardly from said bottom of each of said tubes, and means for connecting each of said loudspeakers to a different one of said leads to be driven only by tone signals pertaining to a separate stop of said organ.

Claim 15

In an electronic organ system, said electronic organ system including an electronic organ providing tone signals pertaining to separate stops of said organ on separate leads, the combination comprising a plurality of vertical hollow tubes, one for each of said stops, a loudspeaker providing a vertically upward radiation pattern secured only at the upper end of each of said tubes, means totally closing the lower end of each of said tubes, acoustic damping means located in the bottom of each of said tubes for damping reflections of acoustic waves upwardly from said bottom of each of said tubes, and means for connecting each of said loudspeakers to a different one of said leads to be driven only by tone signals pertaining to a separate stop of said organ.

Claim 16

The combination according to claim 11, wherein each of said tubes has an enclosed volume appropriate to form a Helmholtz resonator tuned near the lowest frequency of the tone signals its associated loudspeaker is called on to radiate.

Claim 17

The combination according to claim 12, wherein each of said tubes is sufficiently mechanically rigid that it does not acoustically radiate.

Claim 18

The combination according to claim 13, wherein each of said tubes includes a mouth shaped and positioned to simulate visually the mouth of a true pipe organ but of a size selected to resonate with the enclosure of said tube near said lowest frequency.

Claim 19

The combination according to claim 11, wherein said tube has a radiative port near its lower end, said port being sized to resonate with the volume of said tube at a frequency near the low-frequency limit of the range of said signals.

Claim 20

The combination according to claim 11, wherein said first mentioned acoustic absorbing material is a conically tapered hollow in a mass of sound-absorbent material.

Claim 21

The combination according to claim 11, wherein said port extends at least at its upper side into a lip opening in said tube sized for tuning said tube, said lip opening being covered with an acoustically transparent covering material which visually obscures said lip opening.

Claim 22

The combination according to claim 11, wherein said system includes: a supporting sleeve member for said tube at least partially surrounding said tube only at its lower end, there being a V-shaped opening in said sleeve member under said port, said V-shaped opening having its apex extending downwardly and having its base at least as wide as said port.

Claim 23

The combination according to claim 11, wherein said hollow member contains in the lower end thereof a conically tapered hollow in a mass of sound-absorbent material, the apex of said hollow being the lowermost part of said mass.

Claim 24

The combination according to claim 19, wherein said tube contains at least one narrow ring of sound-absorbent material located between the upper end of said hollow member and said port, said ring being positioned to damp selected frequencies of said tone color which might otherwise occur at levels not appropriate to the selected stop.

Claim 25

In an electronic organ system for operation in a room having a reflecting ceiling including an electronic organ having separate output signal leads for separate stops of said organ, separate acoustic radiating means for each of said stops, each of said radiating means including a hollow pipe and an upwardly directed radiator covering the top of said hollow pipe, means closing the lower end of said pipe, a discrete mass of acoustic damping material located at said lower end of said pipe for damping acoustic waves, said pipe being acoustically rigid and having an enclosed volume appropriate to form a Helmholtz resonator tuned near the lowest frequency of said stop, said loudspeaker having the minimum radiative area capable of effectively radiating the band of frequencies covered by said stop, said pipe having an axis directed toward said reflecting ceiling, the radiating area of said loudspeaker being such that the higher frequencies of said stop are reflected from said ceiling in greater proportion than are the lower frequencies and said lowest frequency is radiated approximately omnidirectionally.

Claim 26

In an electronic organ system for operation in a room having a reflecting ceiling including an electronic organ having separate output signal leads for separate stops of said organ, separate acoustic radiating means for each of said stops, each of said radiating means including a hollow pipe and an upwardly directed radiator covering the top of said hollow pipe, means closing the lower end of said pipe, a discrete mass of acoustic damping material located at said lower end of said pipe for damping acoustic waves, said pipe being acoustically rigid and having an enclosed volume appropriate to form a Helmholtz resonator tuned near the lowest frequency of said stop, said loudspeaker having the minimum radiative area capable of effectively radiating the band of frequencies covered by said stop, said pipe having an axis directed toward said reflecting ceiling, the radiating area of said loudspeaker being such that the higher frequencies of said stop are reflected from said ceiling in greater proportion than are the lower frequencies and said lowest frequency is radiated approximately omnidirectionally.

Claim 27

In an electronic organ, lead means for separately conveying tone signals corresponding with separate stops of said organ, a separate Helmholtz resonant hollow tube for each of said stops visually simulating a pipe organ and having an upwardly directed loudspeaker at its upper end and a mass of acoustic wave absorbing material internally in the lower end, and means connecting said leads individually to said loudspeakers, each said tube providing an enclosure for one of said loudspeakers, and means for damping out standing waves internally of said tube, the wall of said tube being acoustically rigid.

Claim 28

In an electronic organ, lead means for separately conveying tone signals corresponding with separate stops of said organ, a separate Helmholtz resonant hollow tube for each of said stops visually simulating a pipe organ and having an upwardly directed loudspeaker at its upper end and a mass of acoustic wave absorbing material internally in the lower end, and means connecting said leads individually to said loudspeakers, each said tube providing an enclosure for one of said loudspeakers, and means for damping out standing waves internally of said tube, the wall of said tube being acoustically rigid.

Claim 29

The combination according to claim 22, wherein each of said tubes includes an acoustically radiative mouth visually simulating the mouth of a pipe of a pipe organ.

Claim 30

A radiative system for an electronic organ having separate output leads on a per stop basis, comprising a plurality of vertical acoustically rigid pipes each including internal means for damping out standing waves, and each including a loudspeaker located in its upper opening, said pipes providing enclosures for said loudspeakers, and means separately connecting said leads to said loudspeakers.

Claim 31

A radiative system for an electronic organ having separate output leads on a per stop basis, comprising a plurality of vertical acoustically rigid pipes each including internal means for damping out standing waves, and each including a loudspeaker located in its upper opening, said pipes providing enclosures for said loudspeakers, and means separately connecting said leads to said loudspeakers.

Claim 32

The combination according to claim 24, wherein each of said loudspeakers has a radiative area selected to radiate approximately omnidirectionally the lowest frequencies of the stop radiated by it and only vertically upwardly the highest frequencies of said stop.