Title:
Loudspeaker baffle board extender
Kind Code:
A1


Abstract:
A Loudspeaker Baffle Board Extender that functionally improves the sound quality of cabinet-type loudspeaker systems. The Extenders are located one to each side of a loudspeaker cabinet and may be built into the cabinet for pull-out/push-in, hinged for folding open or closed or an L-shaped structurally stiff material attached to the loudspeaker cabinet in a manner that enables easy installation and removal or opening or closing.



Inventors:
Marlowe, Stephen Glen (Phoenix, AZ, US)
Application Number:
11/226599
Publication Date:
03/15/2007
Filing Date:
09/15/2005
Primary Class:
Other Classes:
181/148
International Classes:
A47B81/06
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Primary Examiner:
PHILLIPS, FORREST M
Attorney, Agent or Firm:
STEPHEN GLEN MARLOWE (PHOENIX, AZ, US)
Claims:
What is claimed is:

1. A loudspeaker baffle board extender for improving the volume, directionality, projection, frequency response, dynamic range and tonality of audio loudspeaker cabinets, comprising: a loudspeaker baffle board extender; a front leg, having curved or straight ends, for increasing the loudspeaker baffle board radiating surface area; and an attachment leg, for attaching the loudspeaker baffle extender to the loudspeaker cabinet so as to accomplish the purpose of increasing the baffle board radiating surface area or to use the baffle extenders to protect the cabinet's front edges during transport and storage.

Description:

FIELD OF THE INVENTION

The present invention relates to sound reproduction, and, more particularly, to any type of presentation that utilizes audio loudspeaker cabinets as an audible sound source.

BACKGROUND OF THE INVENTION

As a professional musician and music studio Engineer, it was of interest why, when playing live amplified music (i.e.: electric guitar), I could stand just a few feet away from my loudspeaker cabinet yet have trouble hearing its emanating sounds if other musicians were on stage generating a combined volume above moderate volume levels.

It occurred to me that the most “present” sounding loudspeakers I had ever heard were in professional music studios where the speakers (monitors) were literally mounted within a wall or soffit facing out toward the studio's control room where critical recording, mixing and engineering functions were performed. Acoustical Engineers and Acousticians often install loudspeakers directly into a room's wall or soffit thus providing a larger effective front radiating surface surrounding the speaker drivers. This installation technique, often called “soffit mounting” or “flush mounting”, improves frequency linearity, dynamic and transient response and virtually all aspects of a loudspeaker's performance. While the internal enclosed air volume within the soffit behind the drivers is specifically tailored to the drivers' design specifications, soffit mounting allows a larger front baffle than would be possible with a “stand alone” loudspeaker cabinet. Listeners often comment that audio content heard over soffit-mounted loudspeakers is more “present” and “realistic” (as opposed to freestanding cabinet loudspeaker systems)

Well-designed and constructed freestanding audio loudspeaker cabinets specifically optimize the internal air volume of the cabinet enclosure for the chosen drivers (speakers.)

However, the size of the cabinet's front surface (its front baffle board in which the speaker drivers are mounted) can optimally be larger than most cabinets provide, though they may be correct in size to create the required internal cabinet air volume.

This is why the soffit-mounting installation technique is so common in professional studio applications where the ability to critically listen is so very important.

However, not all loudspeaker cabinets can be soffit mounted due to a room's design, space restrictions or the nature of the intended audio applications. Additionally, many loudspeaker systems must remain portable, especially those intended for professional sound reinforcement and musical instrument amplification (i.e.: on stage.)

Therefore, I executed experimentation wherein the baffle boards of professional loudspeaker cabinets were increased by adding one to six inches of surface area to the left and right sides of the cabinet itself in an effort to obtain a degree of sound improvement like that heard from soffit wall mounting.

Surprisingly, when each test cabinet had its baffle board extended, the emanating sound was far more present and easier to hear, even though other loud instruments might be playing nearby. Further testing revealed not only an increase in the apparent presence of the sound, but also enhanced tonality and overall fidelity, again, similar to the improvements wrought from soffit mounting.

This new invention, Loudspeaker Baffle Board Extenders (also called “Sound Wings”), when used in pairs, effectively adds surface area to a loudspeaker cabinet's front baffle board. The Extenders are easily installed and removed making them ideal for portable loudspeaker cabinets—the type often used by musicians and singers and in professional sound reinforcement applications. The Extenders are particularly effective at improving a loudspeaker system's presentation of voice and musical instruments during live performances. For a musician or singer relying upon an on-stage loudspeaker cabinet to hear and present their performance so an audience hears excellent quality sound, this invention is a tremendous boon. Moreover, the Extenders may be used on loudspeaker cabinets for any audio application and purpose.

At high frequencies, a loudspeaker driver radiates sound directly forward. However, generally, the lower frequencies are omni-directional and tend to travel not only directly outwards towards the listener (the audience), but also out towards the sides and rear of the cabinet.

In most rooms, freestanding loudspeaker cabinets are surrounded by walls, ceiling and floor surfaces as well as by various room articles. These nearby surfaces act as “acoustical mirrors” and can generate reflections. Even when a loudspeaker cabinet is set upon a stage or outdoors, some degree of adjacent reflective surfaces can usually be found.

Thus, when the more omni-directional sound waves emanate from the loudspeaker drivers and work their way around to the sides and rear of the cabinet, they ultimately come in contact with said reflective surfaces. The resultant sound reflections then travel back to interfere with the direct sound from the speaker drivers, and further, they reflect back towards the listener.

Depending upon the relative amplitude (volume) and phase (a sound frequency wave's up/down relationship to other frequency waves) of the direct vs. reflected sound, the negative effect created when the two are mixed can be an undesirable difference between various frequencies, which ideally would have similar amplitude and a phase relationships that do not conflict.

When sound waves have conflicting phase relationship, they can literally cancel each other. Under such circumstances, certain frequencies can markedly drop in amplitude causing not only a loss of overall “sound power” emanating from the speaker cabinet, but also an undesirable alteration to the tonal balance (frequency balance) of the sound.

It is of note that when a loudspeaker is mounted flush within a wall (soffit mounted), there is primarily direct radiated sound heard by the listener because, unlike freestanding loudspeaker cabinets, there is no way for omni-directional sound waves to travel off to the sides and towards the rear of a cabinet; the soffit acting as one large extended baffle board. Because of this effect, the total “sound power” radiated into the room is increased compared to a freestanding loudspeaker cabinet that produces sound mixed with spurious, random reflections.

When the Loudspeaker Baffle Extenders are employed, one to each side of a loudspeaker's cabinet, additional baffle board radiation surface is provided and nearby surface reflected sound wave interference reduced. Sound power radiating outward is increased, similar to soffit mounting, and the Extenders hinder the omni-directional lower frequencies from traveling around towards the sides and rear of the cabinet. Moreover, these reflections traveling back to mix with the direct sound are also partially blocked by the Extenders.

Most commercially available speaker cabinets are designed to deliver a somewhat flat frequency response when operated in the free field (with no surrounding reflective surfaces.) If such a cabinet is then flush (soffit) mounted, its frequency response will no longer be flat, but will usually have a noticeable bass boost (a lower frequency increase.)

Similar to this effect, the Extenders also encourage a higher percentage of lower frequencies to radiate directly from the baffle board (the cabinet's existing baffle board plus Extenders). Therefore, more of these frequencies arrive sooner to the listener because they are hindered from traveling around to the sides and to the back of the cabinet. Instead they go in a more forward direction outward towards the listener from the baffle board. These “additional” lower frequencies (as received by the listener) are also improved as regards to their time coherency relationship to the already directional higher frequencies because they are radiating out towards the listener from the baffle board, rather from adjacent reflective room surfaces. And, because the listener effectively hears an increase in the relative amount of lower frequencies to high frequencies, the resulting sound quality can be described as “richer” or as “having more body”. This is due to an increase of mid-bass and bass frequencies relative to the higher direct frequencies as heard by the listener.

The Extenders also offer an improved focus of the sound towards the audience by increasing the percentage of direct radiating audio frequencies and hindering reflected sound.

Soffit mounting also obviates another audible anomaly that a freestanding cabinet imparts: The “diffraction effect”. This effect forms at the very front edges of cabinet when the omni-directional frequencies seek to travel around towards the cabinet's sides and rear. Sometimes referred to as “secondary reflections”, diffracted sound waves can be quite intrusive as they are slightly delayed compared to the original (direct) sound.

This new invention, Loudspeaker Baffle Board Extenders, extends two “edges” of the cabinet's baffle board outward, away from the speaker drivers (the actual original source of the cabinet's sound) and the Extenders effectively reduce the physical size of cabinet's meeting edge planes. Moreover, the addition of the Extenders tends to “break up” the surface of said said cabinet corners by adding the surfaces of the Extenders themselves. As a result, undesirable diffraction effect is reduced; the cabinet's corner edges being effectively altered in a way that results in an audible improvement in sound quality reaching the listener.

In summary, the application of Loudspeaker Baffle Board Extenders limits unwanted secondary sound radiation from the loudspeaker cabinet's original edges and thereby improves the quality of sound radiating towards the listener due to a minimization of diffraction effects.

Some speaker designers have attempted to increase the front baffle board surface area of their cabinet in an effort to obtain a general improvement in sound quality, however, in doing so, they have also increased the overall size of the cabinet, including the internal air volume behind the speaker drivers to an amount in excess of that recommended by the loudspeaker driver's designer/manufacturer, thus degrading the driver's performance.

No one has yet invented an extension device used in pairs to effectively increase the surface area of a loudspeaker cabinet's front baffle board without also altering any other aspect of the cabinet's size or design. Moreover, no one has ever invented an baffle board extension device that is portable so working musicians and singers can easily install and remove them on loudspeaker cabinets designed for portability.

Additionally, loudspeaker cabinet users have attempted to position their cabinets in such a way as to avoid or reduce unwanted spurious reflections from adjacent surfaces. However, such efforts can easily place a cabinet at variance to the best location for the listener to receive quality sound. For example, the speaker cabinet might have far less interaction with a room's surfaces if were to be located very close to a wall, but such a position can alter its frequency response and place it too far away from the listener to receive correct sound.

It is therefore an object of the invention to increase the percentage of directional sound frequencies emanating from a given loudspeaker cabinet and to thereby increase overall sound power with improved fidelity.

It is another object of the invention to limit the edge diffraction effect that normally occurs at the edges of a given loudspeaker cabinet and thereby improve its overall sound quality.

It is another object of the invention to acoustically increase the lower frequency response of the loudspeaker thus enabling the speaker drivers to operate more efficiently and thereby improve overall sound quality.

It is another object of the invention to provide those individuals who are presenting or performing with the aide of cabinet loudspeakers an improved ability to hear their loudspeaker(s) and to better focus and project their sound out to their audience with improved clarity and fidelity.

SUMMARY OF THE INVENTION

In accordance with the present invention, there is provided a Loudspeaker Baffle Board Extender that functionally enhances the sound quality of cabinet-type loudspeaker systems.

Loudspeaker Baffle Board Extenders are particularly effective at improving a cabinet loudspeaker's presentation of voice and music.

Loudspeaker Baffle Board Extenders are either built into a loudspeaker's cabinet for pull-out/push-in, hinged for fold-out/fold-in or as an “L-shape” with one leg of the “L” attached to the cabinet and the other leg of the “L” performing as the baffle board extension.

Utilization of the Loudspeaker Baffle Board Extenders increases the effective front baffle board radiation surface the speaker drivers. This better focuses the sound towards the listener and lessens anomalies common to freestanding speaker cabinets.

All loudspeakers cabinets can benefit from Loudspeaker Baffle Board Extenders for the following reasons:

    • The percentage of direct radiating frequencies is increased for better “presence” of the sound
    • Lessens the cancellation reflections from nearby reflective surfaces
    • Edge diffraction effect is reduced
    • Acoustically, lower frequencies are increased and, therefore, the speaker drivers operate more efficiently.

BRIEF DESCRIPTION OF THE DRAWINGS

A complete understanding of the present invention may be obtained by reference to the accompanying drawings, when considered in conjunction with the subsequent, detailed description, in which:

FIG. 1 is a front view of a left and right pair of loudspeaker baffle board extenders;

FIG. 2 is a side and end view of a single loudspeaker baffle board extender;

FIG. 3 is a perspective view of a pair of loudspeaker baffle board extenders attached to a musical instrument amplifier with built-in loudspeaker;

FIG. 4 is a perspective view of a pair of loudspeaker baffle board extenders attached to a professional sound reinforcement loudspeaker speaker cabinet;

FIG. 5 is a perspective view of a pair of loudspeaker baffle board extenders repositioned upon a musical instrument amplifier cabinet with built-in loudspeaker for transport or storage;

FIG. 6 is a perspective view of a pair of loudspeaker baffle board extenders attached to “slant cabinet” musical instrument loudspeaker cabinet;

FIG. 7 is a front perspective view of a loudspeaker cabinet that has built-in loudspeaker baffle board extenders which can be pulled out or pushed in when not required, such as for transport or storage;

FIG. 8 is a front perspective view of a loudspeaker cabinet having hinged loudspeaker baffle board extenders for fold-out or fold-in when not required, such as for transport or storage;

FIG. 9 is a top view of a loudspeaker cabinet's normal edge diffraction effect reduced by the addition of a loudspeaker baffle extender; and

FIG. 10 is a top view of a loudspeaker cabinet with spurious reflected sound waves (generated from room surfaces or room objects) reduced by the addition of a loudspeaker baffle extender.

For purposes of clarity and brevity, like elements and components will bear the same designations and numbering throughout the Figures.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 is a front view of a left and right pair of Loudspeaker Baffle Board Extenders. The Extenders can be fabricated from plastic, wood, metal, composite, resin, fiber or other ridged material or substance. They can be molded, bent, extruded or formed.

FIG. 2 is a side and end view of a single Loudspeaker Baffle Extender. The angle pictured is at 90 degrees, however some loudspeaker cabinets may require a different angle. For example, if the sides the loudspeaker cabinet are not perpendicular to its front baffle, the Loudspeaker Baffle Extender would be formed with the appropriate angle or shape that would allow it to be connected to the cabinet while placing the Extender's front face parallel to the cabinet's existing baffle surface. Note: Some loudspeakers and their intended audio application may benefit from the Baffle Board Extender being non-parallel to the existing cabinet baffle board surface to help better direct the sound to a specific location and/or to improve frequency response. Also, some loudspeaker designs can benefit from having the Extenders built into the cabinet in such as way that the user can pull or fold them out when required, then return them to their closed (or enclosed) position for storage or transport.

FIG. 3 is a perspective view of a pair of Loudspeaker Baffle Board Extenders attached to a musical instrument amplifier cabinet with a built-in loudspeaker. The Extenders may be attached using hook and loop fastener material (allowing them to be removed) or by utilizing screws, nuts and bolts, glue, double-sided tape or any other method that will attach the Extenders firmly to the cabinet. They may also be hinged or built into the cabinet and pulled or folded out into position.

FIG. 4 is a perspective view of a pair of Loudspeaker Baffle Board Extenders attached to a professional sound reinforcement audio loudspeaker cabinet. (The Extenders are effective on all types of loudspeaker cabinets, including those for home audio, theater, musical instrument amplification, indoor and outdoor sound reinforcement and critical audio monitoring.)

FIG. 5 is a perspective view of a pair of Loudspeaker Baffle Board Extenders repositioned and attached to a musical instrument amplifier cabinet with built-in loudspeaker for transport or storage. Loudspeaker Baffle Board Extenders are used in mirrored pairs and, when attached to the loudspeaker cabinet in reverse, they provide a degree of protection for the cabinet itself. The left Extender is taken off the cabinet's left side and attached to the cabinet's right side and the right Extender is repositioned upon the cabinet's left, as pictured in FIG. 5. In this way the Extenders are properly positioned for transport or storage of the cabinet and, they help protect the cabinet's front side edges. Musical instrument and public address loudspeaker cabinets are frequently transported, moved, stored, shipped and sometimes placed in shipping containers or covered with a fitted protective cover. The ability of the Extenders to be positioned optimally for transport and storage is a considerable benefit to consumers, especially working musicians and audio professionals who use portable loudspeaker cabinet systems.

FIG. 6 is a perspective view of a pair of Loudspeaker Baffle Board Extenders applied to a “slant cabinet” musical instrument loudspeaker cabinet. Loudspeaker Baffle Board Extenders can be formed to accommodate the large size and backward slant of such cabinets, which are frequently used for electric guitar amplification in large performance venues.

FIG. 7 is a perspective view showing Loudspeaker Baffle Board Extenders built into the cabinet, able to be pulled out for use or pushed in when not required, such as for transport or storage.

FIG. 8 is a perspective view showing Loudspeaker Baffle Board Extenders hinged for fold-out or fold-in when not required, such as for transport or storage.

FIG. 9 is a top view showing the addition of a Loudspeaker Baffle Extender reducing the edge diffraction effect common to loudspeaker cabinets.

FIG. 10 is a top view showing the addition of a Loudspeaker Baffle Extender reducing spurious sound reflections (from room surfaces or room objects).

Since other modifications and changes varied to fit particular operating requirements and environments will be apparent to those skilled in the art, the invention is not considered limited to the example chosen for purposes of disclosure, and covers all changes and modifications which do not constitute departures from the true spirit and scope of this invention.

Having thus described the invention, what is desired to be protected by Letters Patent is presented in the subsequently appended claims.