CA3184776A1 - Loudspeaker enclosure - Google Patents

Abstract

A loudspeaker system enclosure includes a housing formed of continuous side wall, a back wall, lower and upper walls, and a front planar elliptically shaped opening, and defining an internal chamber surface having a semi-ellipsoidal shape having a major axis and a minor axis perpendicular to the major axis. The internal chamber surface having a semi-elliptical cross section having a first focal point and a second focal point along the major axis, and a semi-circular cross section along the minor axis. A planar baffle member for positioning across the front opening of the housing, which has first and second sound wave emission openings dimensioned and positioned on a vertical centre line of the baffle member to be concentric with the first and second focal points, respectively. The baffle member further includes mounting openings to mount the one or more speaker drivers between the first and the second sound wave emission openings.

Description

LOUDSPEAKER ENCLOSURE
FIELD OF INVENTION
[0001]. The present invention relates to loudspeaker enclosures, and in particularly, to a speaker enclosure for reducing standing waves and cabinet resonance.
BACKGROUND OF THE INVENTION

[0002]. Many different types of loudspeaker enclosures have been developed for the purpose of reproducing sound. The types of loudspeaker enclosures/cabinets that have been primarily used in sound reproduction include bass reflex, acoustic suspension, horn cabinets, and transmission line.

[0003]. Bass Reflex (Tuned Port /Thiel Ported) - The bass reflex cabinet design is a common, widely accepted cabinet design used currently. The bass reflex design uses a resonating tube mounted inside an opening/hole in the cabinet, to provide low frequency extension (amplification of low frequency sound waves) and emit those sound waves from the cabinet. Although the Bass Reflex cabinet design provides low frequency extension, it does so inefficiently by sound waves reflecting inside the cabinet between hard surfaces making their way to the port in a haphazard fashion.
These cabinets are stuffed with fibrous dampening materials to absorb standing waves and internal sound waves that are not emitted from the port.

[0004]. Acoustic Suspension (Infinite Baffle) - The acoustic suspension cabinet design is a totally sealed enclosure. The internal pressure of the fixed air volume in the cabinet cavity acts like a shock absorber to restrict the movement of the low frequency driver cone, which restricts the generation of low frequency sound waves inside the cabinet.
The theoretical basis of the acoustic suspension cabinet is that a sufficiently large sealed cabinet provides results similar to an infinite baffle. An infinite baffle design has drivers mounted on a flat baffle of theoretical infinite width and height, eliminating anti-phase sound wave radiation caused from sound waves that are longer than the size of the baffle. Although the acoustic suspension design offers an interesting theoretical Date Recue/Date Received 2022-12-29 design focussed on eliminating anti-phase sound wave radiation, fewer loudspeaker cabinet manufacturers use this design.

[0005]. Horn Cabinets - Horn cabinet designs date back to the 17th century, originating in early versions of megaphones used to amplify voices in large gatherings. Very efficient at amplifying sound waves, the convex horn shape directs sound waves from a source in a relatively narrow dispersion pattern forward of the horn. The drivers are mounted on horns that are integrated into the cabinet design, however, the sealed or ported cabinets that enclose the driver have the same limitations as other designs.
Although loud (efficient), the musical quality of horn designs is often not flat over the normal audible frequency range of music (20 hertz to 20,000 hertz)

[0006]. Transmission Line - A transmission line cabinet design is constructed to reflect the low frequency sound waves generated inside the cabinet through a series of internal chambers, with each progressive chamber reducing in size from the previous, using intricately cut angled members to reflect the sound waves through the chambers and out of an opening/hole in the cabinet. Although transmission line cabinets systematically emit low frequency sound waves from the cabinet more efficiently than bass reflex designs, they normally have parallel internal walls that generate standing waves. In each chamber, fibrous batting is used to dampen standing waves and other reflected waves that are not directed into the next chamber. The transmission line cabinet design primarily focusses on low frequency bass extension (amplification) and does not provide emission of mid-range frequency sound waves generated inside the cabinet. Typical transmission line cabinets have a very large number of precision cut pieces making up the internal chambers, and therefore are difficult and costly to manufacture with any degree of precision.

[0007]. Wavelengths of low frequency sounds are very long as shown below as a point of reference and consideration of how they may react when trapped inside a typical rectangular box enclosure:
a. Hertz Wavelength (Meters) b. 20 17.4 c. 30 11.6 Date Recue/Date Received 2022-12-29 d. 40 8.6 e. 60 5.8

[0008]. In all of the types of loudspeaker cabinets listed above, there are three fundamental problems with the quality of sound waves reproduced with the cabinets (due to the internal shape of the cabinet being flat, primarily made from wood fiber based materials, stuffed with fibrous sound dampening material), which are:

[0009]. Standing Waves ¨Sound waves that reflect back and forth between parallel surfaces inside a loudspeaker cabinet. Standing waves create unpleasant and distorted sound waves that are transmitted through the cabinet material to the air surrounding the cabinet.

[0010]. Cabinet Resonance ¨ Similar to standing waves, sound waves that reflect within the cabinet, not necessarily off parallel walls, transmit through the cabinet material to the air outside the cabinet creating an unpleasant cabinet resonance that is audible.

[0011]. Driver Distortion ¨ Sound waves that reflect within the cabinet, striking the drivers that are at that time trying to produce a different sound wave creates driver distortion (or sound elimination if the wave is directly inverse) effecting the clarity of the sound being reproduced by the driver.

[0012]. In each type of loudspeaker cabinet listed above, a large portion of the internal volume of the cabinet is stuffed with fibrous batting to dampen (absorb) the sound waves that are reflecting around inside the cabinet. The purpose of the internal batting is to reduce standing waves, cabinet resonance and driver distortion as described above.
Three of the above discussed loudspeaker enclosures/cabinets have ports or openings that are designed to transmit low frequency sound waves out of the cabinet. The internal batting dampens sound waves, reducing the sound pressure level of waves emitted through the port or opening.

[0013]. The transmission line cabinets are designed in a manner that logically and purposefully directs sound waves out of the cabinet, emitting them through an opening/hole in the cabinet. Although the transmission line cabinet design emits sound waves, the complex Date Recue/Date Received 2022-12-29 flat internal members used to direct the sound waves do so inefficiently, and with the large volumes of fibrous batting inside the cabinet only a small percentage of the sound waves are emitted from the cabinet. In a transmission line cabinet design, the only audible sound waves that are emitted from the opening in the cabinet are the low frequency bass sound waves.

[0014]. Accordingly, there is a need for a loudspeaker enclosure which is not subject to one or more limitations of the prior art.

[0015]. This background information is provided for the purpose of making known information believed by the applicant to be of possible relevance to the present invention. No admission is necessarily intended, nor should be construed, that any of the preceding information constitutes prior art against the present invention.
SUMMARY OF THE INVENTION

[0016]. An object of the present invention is to provide an enclosure for loudspeaker system.

[0017]. In accordance with an aspect of the present invention, there is provided an enclosure for loudspeaker system comprising one or more speaker drivers. The enclosure comprises a) a housing being formed of continuous side wall, back wall, lower and upper walls, and having a front planar elliptically shaped opening, the housing defining an internal chamber surface having a semi-ellipsoidal shape having a major axis and a minor axis perpendicular to the major axis, the internal chamber surface having a semi-elliptical cross section having a first focal point and a second focal point along the major axis, and a semi-circular cross section along the minor axis, and b) a planar baffle member configured to be positioned across the front opening of the housing, the baffle member having first and second sound wave emission openings dimensioned and positioned on a vertical centre line of the baffle member, the first and second sound wave emission openings being positioned to be concentric with the first and second focal points, respectively, the baffle member further comprising one or more mounting openings to mount/secure the one or more speaker drivers between the first and the second sound wave emission openings; such that sound waves generated by the one or more speaker drivers inside the enclosure are reflected from the internal Date Recue/Date Received 2022-12-29 chamber surface and directed to exit the housing via the sound wave emission openings.
BRIEF DESCRIPTION OF THE FIGURES

[0018]. Further features and advantages of the present disclosure will become apparent from the following detailed description, taken in combination with the appended drawings, in which:

[0019]. Fig. 1 depicts a schematic perspective view of the loudspeaker enclosure, in accordance with an embodiment of the present invention.

[0020]. Fig. 2 depicts a schematic perspective view of the housing of the enclosure, in accordance with an embodiment of the present invention.

[0021]. Fig. 3 depicts a schematic view of the housing and the baffle member of the enclosure (in a disassembled form), in accordance with an embodiment of the present invention.

[0022]. Fig. 4 depicts a cross sectional view of the enclosure and the baffle member of the enclosure (in an assembled form), in accordance with an embodiment of the present invention.

[0023]. Fig. 5 depicts a cross sectional view of the enclosure and the baffle member of the enclosure (in an assembled form, including a speaker driver), in accordance with an embodiment of the present invention.

[0024]. Fig. 6 depicts a perspective view of the housing and the baffle member of the enclosure (in assembled form, including a speaker drivers), in accordance with an embodiment of the present invention.

[0025]. Fig. 7 depicts a perspective view of the enclosure and the baffle member of the enclosure (in assembled form), in accordance with an embodiment of the present invention.
Date Recue/Date Received 2022-12-29

[0026]. The specific arrangements shown in the Figures should not be viewed as limiting. It should be understood that the illustrated elements, including and the shape, size and scale, are not drawn in actual proportion to each other.
DETAILED DESCRIPTION OF THE INVENTION

[0027]. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0028]. Unless the context requires otherwise, throughout this specification and claims, the words "comprise", "comprising" and the like are to be construed in an open, inclusive sense.

[0029]. The articles "a" and "an" are used herein to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article. By way of example, "an element"
means one element or more than one element.

[0030]. As used herein, the term "about" refers to approximately a +1-10%
variation from a given value. It is to be understood that such a variation is always included in any given value provided herein, whether or not it is specifically referred to.

[0031]. The term semi- elliptical as used herein refers to half of an ellipse as dissected by its centre axis as depicted below. An ellipse as defined mathematically, is a plane curve surrounding two focal points (shown as the egg shaped line below). The focal points of an ellipse are two points F1 and F2 on the ellipse's centreline along its major axis that are equidistant from the centre point "C". The sum of the distances from any point P on the ellipse to the two focal points is constant and equal to the overall length of the major axis (PF1 + PF2 = 2a). (2a = the distance from point -a to point a.) Date Recue/Date Received 2022-12-29 PEt+PF2=2a b e=fla 4P iihhii._,4411111 -a a -b

[0032]. The present invention provides an enclosure for a loudspeaker system, for efficiently emitting the sound waves generated by the back of a speaker driver from inside a speaker enclosure to the outside, for improving the quality of sound.

[0033]. The enclosure of the present invention comprises a housing formed of a continuous side wall, a back wall, lower and upper walls, and provided with a front elliptically shaped planar opening. The housing defines an internal chamber surface having a semi-ellipsoidal shape having a major axis and a minor axis perpendicular to the major axis. The internal chamber surface has a semi-elliptical cross section having a first focal point and a second focal point along the major axis, and a semi-circular cross section along the minor axis.

[0034]. The enclosure further comprises a planar baffle member configured to be positioned across the front opening of the housing. The baffle member has first and second sound wave emission openings appropriately dimensioned and positioned on a vertical centre line of the baffle member. The first and second sound wave emission openings are positioned to be concentric with the first and second focal points, respectively. The baffle member further comprises one or more mounting openings to mount/secure the one or more speaker drivers between the first and the second sound wave emission openings, such that sound waves generated by the one or more speaker drivers inside the enclosure are reflected by the internal chamber surface and directed to exit the housing via the sound wave emission openings.

Date Recue/Date Received 2022-12-29

[0035]. The baffle member is further configured to secure electrical connections and/or crossover network of the loudspeaker system.

[0036]. In some embodiments, the enclosure further comprises appropriately dimensioned resonating tube extending outwardly from one of the sound wave emission openings.

[0037]. In some embodiments, the major axis of the internal chamber surface is oriented vertically, and the first sound wave emission opening and the first focal point is located above the speaker driver(s) and the second sound wave emission opening and the second focal point is located below the speaker driver(s).

[0038]. In some embodiments, a resonating tube extends outwardly from the second (lower) sound wave emission opening to provide low frequency sound pressure level extension (amplification), and the upper sound wave emission opening does not have a resonating tube, as the purpose of the upper sound wave emission opening is to emit mid and bass range sound waves in a more widely dispersed pattern to enhance sound wave dispersion and generate a more open sound stage to the listener.

[0039]. Due to the semi - ellipsoidal shape of the internal chamber surface of the enclosure, the sound waves being generated by the drivers on the inside of the enclosure are reflected and directed to exit at the focal points of the semi-ellipsoid along the vertical centre line of the baffle.

[0040]. In some embodiments, one of the mounting openings is configured to receive a low frequency speaker driver (woofer), such that the low frequency speaker driver is centered on the vertical centre line of the baffle member between the first and the second focal points to attain the desired sound pressure level emission from both focal points. .

[0041]. In some embodiments, the centre point of the low frequency speaker driver coincides with the centre point of the elliptical front opening.

Date Recue/Date Received 2022-12-29

[0042]. In some embodiments, the centre of the low frequency speaker driver mounting opening coincides with the centre point of the elliptical front opening.

[0043]. In some embodiments, the low frequency speaker driver is positioned at the horizontal centre line of the baffle member.

[0044]. In some embodiments, the centre point of the low frequency speaker driver is placed on the vertical centre line of the baffle member between the lower focal point and the centre point of the elliptical front opening

[0045]. In some embodiments, the centre of the low frequency speaker driver mounting opening is placed on the vertical centre line of the baffle member between the lower focal point and the centre point of the elliptical front opening.

[0046]. The sound waves reproduced by the woofer are the lower frequencies typically in the range of 20 hertz to 600 hertz which are long sound waves that create a large amount of cabinet resonance and internal distortion in a typical rectangular cabinet.
Therefore, it is desired to have these lower frequency sound waves emitted out of the cabinet with minimal internal reflections. The lower frequency sound waves transmitted through the lower sound wave emission opening through the resonating tube that extends outside of the enclosure provide sound pressure level extension (amplification).

[0047]. In some embodiments, one of the mounting openings is configured for mounting a mid-range driver directly above the low frequency driver on the centre line of the baffle, close to the sound wave emission opening positioned above the low frequency driver.
The efficient emission of mid-range frequency sound waves through the upper emission opening in a widely dispersed pattern improves what is commonly referred to as "sound stage".

[0048]. The dimensions of the sound emission openings and/or the resonating tube (i.e. width, length, wall thickness) can be determined based on the internal volume of the enclosure, the size of the frequency driver (woofer), and desired frequency amplification.

Date Recue/Date Received 2022-12-29

[0049]. In some embodiments, the sound wave emission openings each have a diameter from about 2" to about 5".

[0050]. In some embodiments, the resonating tube has a diameter from about 2"
to about 5"
and a length from about 4" to about 10". In some embodiments, the resonating tube has a diameter from about 2.5" to about 3.5" and a length from about 4.5" to about 65".

[0051]. The housing of the enclosure of the present invention is made of high density sound wave reflective material, such as concrete, cement, etc., to achieve a high level of sound wave reflection and minimize sound wave transmission through the walls of the housing. In some embodiments, the high density sound wave reflective material comprises a mixture of cement and sand.

[0052]. The baffle member can be constructed from high density, high rigidity material, which can be cut or machined to install speaker drivers. In some embodiments, the baffle member is made of a high density, high rigidity material such as hard wood.

[0053]. The resonating tube can be constructed from high density, high rigidity material which can be cut or machined.

[0054]. Due to the specific shape of the housing and the specific positioning of the sound emission openings on the baffle member, the loudspeaker enclosure of the present invention can reduce or minimize generation of standing waves inside the loudspeaker enclosure, and reduce cabinet resonance by directing the sound waves out of the housing through the sound emission openings, leaving fewer internal sound waves reflecting back to hit the internal walls of the housing multiple times.

[0055]. High density moulded construction of the housing further reduces cabinet resonance by reducing sound wave transmission through the cabinet material to the air on the outside of the cabinet.

[0056]. The enclosure of the present invention can also reduce driver sound distortion, which is caused by sound waves being emitted from a vibrating driver (speaker cone) striking the inside surface of the enclosure and reflecting back towards that driver or another Date Recue/Date Received 2022-12-29 driver and striking the drivers at a delay. Due to the elliptical shape of the interior surface of the housing, more sound waves are emitted out of the enclosure through the emission openings, and fewer internal sound waves reflect back to hit the drivers that are vibrating at a different frequency to generate different sound waves at that time.

[0057]. The enclosure of the present invention does not require the use of fibrous materials inside the housing to dampen the internal sound waves, as the enclosure is configured to emit the sound waves from the enclosure, thereby reducing the cost of manufacturing.

[0058]. The present enclosure further improves sound stage imaging due to more reflected mid-range sound waves being emitted from the enclosure, rather than being dampened inside the enclosure.

[0059]. The placement of an appropriately sized resonating tube on the outside of the baffle further provides low frequency sound wave extension (amplification), which does not interfere with the geometric principles of the interior surface of the enclosure, and does not interfere with the efficient transmission of sound waves through each emission opening to the outside of the enclosure.

[0060]. The present enclosure provides flexibility in locating the loudspeaker enclosure within a listening room. Placement of the present enclosure from the side wall or rear wall surfaces of the housing in a listening room has no effect on sound waves transmitted from this enclosure since all sound waves are transmitted in a forward direction from the baffle. Several other loudspeaker cabinet manufacturers typically suggest a specific placement of the cabinet in the listening room, measured from side walls or rear walls to optimize the musicality of the sound produced by those loudspeakers.

[0061]. To gain a better understanding of the invention described herein, the following examples are set forth with reference to the accompanying drawings, which are not drawn to scale, and the illustrated components are not necessarily drawn proportionately to one another. It will be understood that these examples are intended to describe illustrative embodiments of the invention and are not intended to limit the scope of the invention in any way.

Date Recue/Date Received 2022-12-29 EXAMPLES

[0062]. Figs. 1, 3 and 4 depict an exemplary loudspeaker enclosure (10) of the present invention, which comprises a housing (12) and a planar baffle member (14) (shown without any speaker component).

[0063]. As shown in Fig. 2, the housing (12) is formed of continuous side wall, back wall, lower and upper walls (14a, 14b, 14c and 14d, respectively), and has a planar front opening (16). The housing defines an internal chamber surface (18) having a semi-ellipsoidal shape having a major axis (y-y') and a minor axis (x-x') perpendicular to the major axis (Figs. 2 and 3). The internal chamber surface has a semi-elliptical cross section having a first focal point (F1) and a second focal point (F2) along the major axis, and a semi-circular cross section along the minor axis (Figs. 4 and 5).

[0064]. The planar baffle member (14) is configured to be positioned across the front opening (16) of the housing (Figs. 1 and 4), and has a vertical centre line (L-L') and a horizontal centre line (T-T') (Fig. 3). The baffle member has a first/upper sound wave emission opening (20) and a second/lower sound wave emission opening (22). Both openings are dimensioned and positioned along the vertical centre line (L - L') of the baffle member. The first and second sound wave emission openings are positioned to be concentric with the first and second focal points (F1, F2), respectively as shown in Fig.
4. The baffle member further comprises mounting opening (24) to mount/secure a speaker driver located between the first and the second sound wave emission openings.

[0065]. In this example, the major axis of the internal chamber surface is oriented vertically (y-y'), and the first sound wave emission opening (20) and the first focal point (F1) are located above the speaker driver mounting opening (24) and the second sound wave emission opening (22) and the second focal point (F2) are located below the speaker driver mounting openings.

[0066]. In this example, the baffle member further comprises a resonating tube (26) extending outwardly from the lower sound wave emission opening.

Date Recue/Date Received 2022-12-29

[0067]. The speaker driver mounting opening (24) is configured to receive a low frequency speaker driver/woofer (28), such that the centre of the mounting opening (24) or the centre point of the driver coincides with the centre point of the elliptically shaped front opening (Figs. 4 and 5).

[0068]. Alternatively, the woofer mounting opening (24) is configured, such that the centre of the mounting opening (24) is placed between the lower focal point and the centre point of the elliptically shaped front opening (Fig. 3).

[0069]. As shown in Fig. 5, due to the semi - ellipsoidal shape of the internal chamber surface (18) of the enclosure (10), the sound waves (30) that are being generated by the driver (28) on the interior surface of the enclosure are reflected from the back and side walls of the housing and directed to exit at or near the focal points (F1, F2) of the semi-ellipsoid along the vertical centre line of the baffle.

[0070]. The sound waves reproduced by the woofer are the lower frequencies typically in the range of 20 hertz to 600 hertz which are long sound waves that create a large amount of cabinet resonance and internal distortion in a typical rectangular cabinet.
The lower frequency sound waves transmitted out from the enclosure via the lower sound wave emission opening (22) when passed through the resonating tube (26) that extends outwardly from the enclosure provide sound pressure level extension (amplification).

[0071]. Figs. 6 and 7 depict another example of the enclosure of the present invention, wherein the housing (12) is same as in the example depicted in Fig. 1 to 5. In this example, the baffle member (14) is provided with two speaker driver mounting openings (24a, 24b), wherein opening (24a) is configured to mount a mid-range driver (28a) directly above the low frequency driver (28b) on the centre line of the baffle and close to the sound wave emission opening (20). In this example, the baffle member further has a high frequency driver/tweeter (30) mounted therein, which has a sealed box enclosure surrounding the back of the driver.

[0072]. As depicted in Fig. 7, the baffle members of the present invention are further configured to secure electrical connections and/or crossover network (32) of the loudspeaker system.

Date Recue/Date Received 2022-12-29 COMPARATIVE TESTS

[0073]. Several tests have been performed, measuring and comparing the sound produced by the same loudspeaker system comprising the enclosure of the present invention, having drivers, crossover network, wiring, etc. mounted on the baffle member, in comparison to a typical rectangular, tuned port loudspeaker cabinet of recommended dimensions with non-parallel side walls (herein after referred as comparative cabinet).
The comparative cabinet was built from high density particle board, two 3/4"
thick layers were laminated together and the cabinet was internally braced at its third section heights to provide a cabinet that was very dense, thick and rigid. In addition, the comparative cabinet's sides were tapered in towards the back to minimize parallel surfaces. Music and sounds reproduced by loudspeaker systems were compared by both measurable specifications and subjective listening tests of clarity, quality and musicality.
COMPARATIVE TEST RESULTS

[0074]. "Realistic" brand sound pressure level meter, from Radio Shack, was used to measure the decibel level of individual frequency sound waves from each loudspeaker cabinet.
The meter was placed at the same height and distance from the centre line of each cabinet.

[0075]. The test results of the single frequency decibel level test indicate that both loudspeakers reproduced individual sound waves very closely at all frequency levels.
This test confirmed that the drivers, crossover networks and wiring were consistent and that the designed internal volume of the test loudspeaker enclosure/cabinet of the present invention provided individual sound frequency reproduction levels virtually the same as the comparative speaker cabinet.
COMPARATIVE MUSIC LISTENING TEST RESULTS

[0076]. Despite the single frequency sound pressure level showing nearly identical results, the comparative music listening tests exhibited significant differences in the clarity, precision, quality and sound stage of music. Several individuals described the Date Recue/Date Received 2022-12-29 difference as "the difference between day and night". The test loudspeaker enclosure/cabinet was preferred by each listener, the common preferences documented were:
1. Improved clarity in bass and mid-range frequencies.
2. Subtle musical nuances were more noticeable such as background vocals, soft vocal elements, bass string reverberation.
3. Bass lines were more clearly defined, individual notes were more distinguishable and produced with better accuracy and clarity. Subtle bass fret sounds were noticeable from the test loudspeaker enclosure/cabinet that were not noticeable from the comparative loudspeaker cabinet. Some listeners described the bass frequency music produced by the comparative loudspeaker cabinet as "muffled" compared to the test loudspeaker enclosure/cabinet.
4. Mid-range instruments and voices had a better sound stage, the sound came from a much wider field outside of the individual mid-range drivers, compared to the relatively directional mid-range produced by the comparative loudspeaker cabinet. Some listeners described the mid-range music reproduced by the test loudspeaker cabinet as "more open" or "less restricted".

[0077]. The comparative listening results reflected characteristics consistent with the design objectives of the test loudspeaker cabinet:
a. fewer standing waves b. less cabinet resonance c. less driver distortion from reflected sound waves d. increase in sound waves emitted from the cabinet e. less damping of sound waves from internal fibrous materials

[0078]. There were no distinguishable differences noted in the high frequency musical sounds produced by each loudspeaker cabinet. The high frequency driver (tweeter) has a sealed box enclosure surrounding the back of the driver, therefore sound waves are only emitted from the front of the driver and are not affected by the cabinet and if placed at the same height on each cabinet sound indistinguishable.

[0079]. Although the invention has been described with reference to certain specific embodiments, various modifications thereof will be apparent to those skilled in the art Date Recue/Date Received 2022-12-29 without departing from the spirit and scope of the invention. All such modifications as would be apparent to one skilled in the art are intended to be included within the scope of the following claims.

Date Recue/Date Received 2022-12-29

Claims (13)

THE EMBODIMENTS OF THE INVENTION FOR WHICH AN EXCLUSIVE PROPERTY OR
PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. An enclosure for loudspeaker system comprising one or more speaker drivers, the enclosure comprising:
a housing being formed of continuous side wall, back wall, lower and upper walls, and having a front planar elliptically shaped opening, the housing defining an internal chamber surface having a semi-ellipsoidal shape having a major axis and a minor axis perpendicular to the major axis, the internal chamber surface having a semi-elliptical cross section having a first focal point and a second focal point along the major axis, and a semi-circular cross section along the minor axis; and a planar baffle member configured to be positioned across the front opening of the housing, the baffle member having first and second sound wave emission openings dimensioned and positioned on a vertical centre line of the baffle member, the first and second sound wave emission openings being positioned to be concentric with the first and second focal points, respectively, the baffle member further comprising one or more mounting openings to mount/secure the one or more speaker drivers between the first and the second sound wave emission openings;
such that sound waves generated by the one or more speaker drivers inside the enclosure are reflected from the internal chamber surface and directed to exit the housing via the sound wave emission openings.

2. The enclosure of claim 1, further comprising a resonating tube extending outwardly from one of the sound wave emission openings.

3. The enclosure of claim 2, wherein the major axis of the internal chamber surface is oriented vertically, and the first sound wave emission opening and the first focal point are located above the one or more speaker drivers mounting opening and the second sound wave emission opening and the second focal point are located below the one or more speaker drivers mounting openings, and the resonating tube extends outwards from the second sound wave emission opening.

4. The enclosure of claim 3, wherein one of the one or more mounting openings is configured to receive a low frequency speaker driver (woofer), such that the low frequency speaker driver is centered on the vertical centre line of the baffle member between the first and the second focal points.

5. The enclosure of claim 4, wherein the centre point of the low frequency speaker driver coincides with the centre point of the elliptically shaped front opening.

6. The enclosure of claim 4, wherein the centre point of the low frequency speaker driver is placed between the lower focal point and the centre point of the elliptically shaped front opening.

7. The enclosure of claim 4, wherein the centre of the low frequency speaker driver mounting opening coincides with the centre point of the elliptically shaped front opening.

8. The enclosure of claim 4, wherein the centre of the low frequency speaker driver mounting opening is placed on the vertical centre line of the baffle member between the lower focal point and the centre point of the elliptically shaped front opening.

9. The enclosure of any one of claims 4 to 8, wherein one of the one or more mounting openings are configured to mount a mid-range driver directly above the low frequency driver on the centre line of the baffle, close to the sound wave emission opening positioned above the low frequency driver.

10. The enclosure of any one of claims 1 to 9, wherein the housing is made of high density sound wave reflective material.

11. The enclosure of claim 10, wherein the high density sound wave reflective material comprises a mixture of cement and sand.

12. The enclosure of any one of claims 1 to 11, wherein the baffle member is made of high density, high rigidity material.

13. The enclosure of claim 12, wherein baffle member is made of hard wood.