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Title:
LOUDSPEAKER ENCLOSURE
Document Type and Number:
WIPO Patent Application WO/2017/125864
Kind Code:
A1
Abstract:
There is provided a loudspeaker enclosure comprising a loudspeaker (20), an acoustic enclosure (1), and a first deflector panel (2), said loudspeaker (20) being mounted onto said first deflector panel (2), and said first deflector panel (2) being mounted onto said acoustic enclosure (1) in a spaced manner by a predetermined distance and by supporting means, the loudspeaker enclosure is characterized in that said first deflector panel (2) has at least one surface dimension that is greater than at least one surface dimension of the acoustic enclosure (1).

Inventors:
DAVID PALIANI (IT)
Application Number:
PCT/IB2017/050266
Publication Date:
July 27, 2017
Filing Date:
January 18, 2017
Export Citation:
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Assignee:
DAVID PALIANI (IT)
International Classes:
H04R1/28
Foreign References:
US5056616A1991-10-15
US20040008857A12004-01-15
US4131179A1978-12-26
Attorney, Agent or Firm:
IACOBELLI, Daniele Teodoro (IT)
Download PDF:
Claims:
CLAIMS

1. Loudspeaker enclosure comprising a loudspeaker (20), an acoustic enclosure (1), and a first deflector panel (2), said loudspeaker (20) being mounted on said first deflector panel (2), and said first deflector panel (2) being mounted on said acoustic enclosure (1) in a spaced manner with a predetermined distance and by supporting means, the arrangement being such that there is an air channel (4) between said loudspeaker (20) and said acoustic enclosure (1),

characterized in that said first deflector panel (2) has at least one surface dimension that is greater than at least one surface dimension of said acoustic enclosure (1) .

2. Loudspeaker enclosure according to the preceding claim, further comprising a second deflector panel (3) integrally mounted onto said acoustic enclosure (1) .

3. Loudspeaker enclosure according to the preceding claim, wherein said second deflector panel (3) it is arranged facing said first deflector panel (2) and spaced from the latter, and in a manner such that as to create an air channel (4) delimited by surfaces of said first and second deflector panels (2,3), respectively.

. Loudspeaker enclosure according to the preceding claim, wherein said air channel (4) it is delimited by surfaces defined by said first deflector panel (2) and a facing surface of said acoustic enclosure (1) , and by facing surfaces of said first and second baffle panels (2,3) and for the entire length of the latter, the arrangement being such that an air flow generated by a pressure wave by said loudspeaker (20) it is channelled along said air channel (4) .

5. Loudspeaker enclosure according to any of the preceding claims 2 to 4, wherein said second deflector panel (3) comprises sound damping means (5) at the surface thereof which define said air channel (4), and for damping the sound emitted by said pressure wave from the loudspeaker (20) .

6. Loudspeaker enclosure according to the preceding claim, wherein said sound damping means of the sound wave pressure emitted by the loudspeaker (20) comprises a plurality of longitudinal elements (5) which extend substantially along the whole width of said second deflector panel (3), each element (5) having an height such as to be coplanar with said acoustic enclosure (1) surface, and each element (5) being spaced from the other.

7. Loudspeaker enclosure according to the preceding claim, wherein the arrangement of said longitudinal elements (5) on the surface of said second deflector panel (3) is such that they are arranged spaced one from the other another with an increasing respective distance.

8. Loudspeaker enclosure according to any of the preceding claims 5 to 7, wherein the arrangement of the plurality of elements (5) on said deflector panel (3) create a series of spaces (50) each delimited by the air channel (4) and by each element (5) .

Description:
"LOUDSPEAKER ENCLOSURE"

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DESCRIPTION

The present invention relates to a loudspeaker enclosure and, more specifically, to an improvement for loudspeaker enclosures manufactured according to the RJ enclosure technique.

Prior art

As already known in the art, the manufacturing scheme of a loudspeaker enclosure according to the RJ technique (or, according to the RJ load theory, also called "compensated baffle", and which takes its name from the initials of the surnames of its founders, Frank Robbins and William Joseph) provides a loudspeaker which is mounted onto a panel, and the latter is in turn mounted in a spaced manner by means of screws or pins to an acoustic enclosure. The acoustic enclosure has a hole of the same diameter of the loudspeaker and which allows the housing of part of the loudspeaker (i.e., the rear part of the loudspeaker) into the hole.

This particular manufacturing technique results in an acoustic enclosure having a loudspeaker which it is not hermetically sealed. More specifically, the RJ manufacturing technique provides that the acoustic enclosure which is back positioned to the loudspeaker, it acts like a Helmholtz resonator.

Examples of this type of loudspeaker enclosure arrangements are described in US6504939B1 and US2002136423A1.

Nevertheless, according to these manufacturing techniques on one hand there is an advantage consisting of the gain of the rear output of the loudspeaker improving the audio scene, but on the other hand this arrangement decreases the loudspeaker efficiency due to the pressure high losses due to the non-tightness of the system.

In particular, and limiting exclusively to such acoustic phenomenon (i.e., mechanical and fluid dynamical phenomenon) and given the particular configuration of the loudspeaker enclosure, wherein the loudspeaker it is mounted onto a baffle panel spaced from the enclosure (which is the only manner to shield the front sound emission from the rear sound emission) , it was found that between the panels there is a fluid dynamical bottleneck. The fluid bottleneck it is precisely the cause of the pressure loss, and thereby the efficiency of the loudspeaker .

Accordingly, the present invention aims to solve the above problems of loss of pressure in the enclosures manufactured according to the RJ technique of the state of the art. Furthermore, the present invention allows the use of small-diameter loudspeakers with enclosures manufactured according to the RJ technique.

Brief description of the invention

The object of the present invention is to solve the aforesaid drawbacks by providing an loudspeaker enclosure that includes a loudspeaker, an acoustic enclosure, and a first deflector panel, the loudspeaker being mounted onto the first deflector panel, and the first deflector panel being mounted onto the acoustic enclosure in a spaced manner by a predetermined distance and by means of supporting means, the loudspeaker enclosure it is characterized in that the first panel has at least one surface dimension that is greater than at least one surface dimension of the acoustic enclosure.

According to one aspect of the present invention, the loudspeaker enclosure further comprises a second deflector panel integrally mounted on the acoustic enclosure.

According to another aspect of the invention, the second deflector panel it is arranged frontally to the first deflector panel and spaced from the latter, and in a manner such that as to create a fluid channel delimited by the two surfaces of said first and second deflector panels, respectively .

According to a further aspect of the invention, the loudspeaker enclosure also comprises damping means for damping the loudspeaker pressure emissions.

Therefore, the present invention provides a loudspeaker enclosure substantially according to the appended claims.

Detailed description of the invention

A detailed description of a preferred embodiment of the loudspeaker enclosure of the present invention will now be given, given as a non-limiting example and with reference to the annexed figures, wherein:

Figure 1 is a schematic front elevational view of the loudspeaker enclosure of the present invention;

Figure 2 is a schematic longitudinal section view of the loudspeaker enclosure of the present invention; and

Figures 3A and 3B are front elevational views of two components of the loudspeaker enclosure of the present invention .

It has to be pointed out that the illustrations of the present embodiment refer to a loudspeaker enclosure that includes a small-diameter loudspeaker (for example, 10 cm diameter loudspeakers), but obviously the invention is not limited to this embodiment and/or sizes.

With reference to Figures 1 and 2 and according to the present invention, the loudspeaker enclosure comprises a acoustic amplification main body consisting of an acoustic enclosure 1 having a substantially (but not limited) cubic shape. The acoustic enclosure 1 comprises a circular hole integrally obtained at one of its faces and having a complementary diameter to the diameter of a loudspeaker 20.

At the face where it is housed the loudspeaker 20 there is mounted a first deflector panel 2 that has a substantially rectangular shape and having two shorter sides of slightly greater length than the length of the side of the acoustic enclosure 1, while the two longer sides of the panel 2 being of an approximately three times longer than the length of the short sides.

This first panel 2 mounts the loudspeaker 20. In addition, the panel 2 is mounted onto the acoustic enclosure 1 in a manner spaced from the same by a specific predetermined distance which creates a space 4 (Figure 2) . The distance 4 is chosen depending on the desired performance.

In order to mount the first deflector panel 2 onto the acoustic enclosure 1 in a spaced manner there are provided as spacing supporting means consisting of pins or screws with respective sleeves (not shown in the figure) .

With particular reference now to Figures 2, 3A and 3B and according to the present invention, the loudspeaker enclosure further comprises a second deflector panel 3 which is mounted integrally onto the acoustic enclosure 1 and at an edge of the same and frontally facing the first deflector panel 2 (i.e., in figure 2 the second panel 3 extends downwards) .

As it is apparent from Figures 3A and 3B, the second deflector panel 3 has a rectangular shape, and has shorter sides of same size of the sides of the acoustic enclosure 1 (therefore, having a smaller size than the size of the deflector panel 2), and the longer sides being of substantially same sizes to that of the deflector panel 2.

The arrangement of the first panel 2 and the second panel 3 on the acoustic enclosure 1 is such that they are mounted in a facing condition but spaced from each other by a predetermined gap. The two panels 2 and 3 are adjacent but completely open.

In this manner, it is generated an air channel 4 delimited by the surface that faces frontally both deflector panel 2 and the surface of the acoustic enclosure 1, and both the two deflector panels 2 and 3 and for the whole length of the latter.

The air flow moved by the pressure generated from the loudspeaker 20 coming from the circular hole of the acoustic enclosure 1 is then also conveyed along the air channel 4, and moves along the surface of the air channel 4 and is thus slowed down by surface friction. As will be apparent to those skilled in the relate d art, it has to be noted here that according to the above illustrated arrangement, the deflector panels 2 and 3 when suitably dimensioned in length and width, it is obtained a precise magnification of a precise portion of frequencies.

Moreover, as it is possible to note in Figures 2 and 3A, the panel 3 has at its surface facing the air channel 4 a plurality of longitudinal elements 5 which extend across the whole width of the panel 3, while the height of said longitudinal elements 5 it is such as to results being coplanar with the surface of the acoustic enclosure 1 ( figure 2 ) .

Furthermore, and as it is evident in Figure 3A the arrangement of the longitudinal elements 5 on the surface of the deflector panel 3 it is such that they are arranged spaced one from another with an increasing spacing distance (spacing distance growing exponentially) .

As shown in Figures 2 and 3A, the arrangement of the elements 5 onto the panel 3 creates a series of spaces 50 delimited by the elements 5 and the air channel 4.

The air pressure wave when encountering the barriers formed by the multiplicity of longitudinal elements 5 onto the panel 3, it is constrained to follow the path imposed by said longitudinal elements 5 through the spaces 50, further slowing its speed, and thereby contributing to further increase the pressure and surprisingly containing within limits the lateral scattering. The pressure increase generates a correct damping effect on the loudspeaker enclosure .

For the calculation of the increasing distance values between each of the longitudinal elements 5, the present inventor has operated as follows:

Representing the present RJ system on Cartesian axis, it is known that the loudspeaker fundamental data are its maximum stroke "x" (identified as Xmax) , and its mechanical stiffness CMS (that is the mechanical stiffness of the loudspeaker suspensions, and it is expressed in millimetres / Newton) , since in this particular arrangement it must rely on the mechanical features of the loudspeaker in order to maintain linear the stroke.

Then, parameterizing the whole system and rendering the same dependent from the loudspeaker CMS work, it is obtained the following logarithmic equation:

y = log (CMS * x)

For example, in the case of a loudspeaker with a

CMS = 0,83 mm / N, it is obtained

y = log (83x)

This equation produces the following graph (both in the real and in the imaginary fields)

where -1 < x < +1

At this point, a "virtual" model of the loudspeaker / acoustic enclosure system it is obtained as a function of the loudspeaker work, and the relevant time domain can be studied by tracing a square onto the Cartesian axis choosing a generic neighbourhood, according to the following equation:

x (t) = 2 Sine (t)

t / 83 = 2 Sine (t) ; or

t = 166 Sine (t)

For convenience, in the graph shown above it illustrated the width of the panel 3 in the neighbourhood -2 < x <2 and in a time -0.5 < t < +0.5 .

So, according to the present equation and as illustrated in the graphs above, the longitudinal elements 5 will become each of 0.83 in height and spaced one from the other by a distance which is defined by the intersection of the straight line on the sinusoidal curves (last graph) .

The loudspeaker enclosure of the present invention has several advantages.

A first advantage consists in the possibility of using small sized loudspeakers (full-range or multi-way) in order to achieve good performances and limit overall dimensions.

Another advantage lies in the fact of functioning with total absence of turbulence, unlike the loudspeakers enclosures of the state of the art, where the turbulences are generated from the loudspeaker itself. As a matter of fact, the shaping of the air channel 4 after reaching a regime pressure, it ensures a constant backpressure.

A further advantage resides in the fact that the arrangement of said deflector panels 2 and 3 allows a greater rear sound emission of the loudspeaker, advantaging the performance of the reverberant field. In fact, unlike common systems, the present arrangement also emits directly from the four sides of the enclosure.

Another advantage lies in the fact of the possibility of applying greater power to the loudspeaker installed. The air channel 4 has the same properties of a BASS REFLEX channel, and then it features the magnification of the lower frequencies, differing to the RJ loudspeakers enclosures of state of the art.

A further advantage resides in the fact that according to the present loudspeaker enclosure, the developed pressure along the air channel 4 is determined by the loudspeaker work, unlike the BASS REFLEX of the state of the art which being not damped it worsens the response in the time domain of the frequency.

Therefore, with the loudspeaker enclosure of the present invention it is obtained a marked improvement in performance in terms of consistency in the low range.