US 3754618 A
A speaker system employs a baffle board in the front part of the cabinet with a woofer mounted on said baffle board. A self-contained auxiliary speaker device covering middle and high-pitch tone ranges is further mounted on the baffle board in such a manner that the angle between the auxiliary speaker device and the baffle board can be varied as desired.
Description (OCR text may contain errors)
United States Patent 1191 Sasaki Aug. 28, 1973 SPEAKER SYSTEM UNITED STATES PATENTS 2,109,431 2/1938 McDonald 181/31 B 3,022,853 2/1962 Santi 181/27 A 3,347,607 10/1967 Knize 181/31 5 3,379,276 4/1968 Goettl 181/31 B 3,491,204 1/1970 Sherno 181/31 8 Primary Examiner-Stephen J. Tomsky Attorney-Richard C. Sughrue, Donald E. Zinn et a1.
[ ABSTRACT A speaker system employs a baffle board in the front part of the cabinet with a woofer mounted on said baffle board. A self-contained auxiliary speaker device covering middle and high-pitch tone ranges is further mounted on the baffle board in such a manner that the angle between the auxiliary speaker device and the baffle board can be varied as desired.
4 Claims, 6 Drawing Figures Patented Aug. 28, 1973 3,754,618 I 2 Sheets-Sheet l Patentea Aug. 28, 1973 2 Sheets-Sheet 2 SPEAKER SYSTEM BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a speaker system, and more particularly to a type thereof wherein a tweeter and a middle range speaker are arranged in a special manner.
2. Description of the Preferred Embodiment Because the wavelengths of the middle and high pitch tones are shorter than those of the low pitch tones, the directivity of the middle and high pitch tones is sharper than that of the low pitch tones. This means that the sound field of an output tone from a loudspeaker is increasingly narrower in accordance with the increase in the tone frequency, whereby the middle and high pitch tones suffer severe attenuation in a direction offset greater than 30 to 60 from the central axis of the loudspeaker, depending on the frequency.
Accordingly, when a stereophonic reproduction is desired employing conventional speaker systems (A,A) placed at two comers or a room, adjacent to a wall thereof, as shown in FIG. la which will be described hereinafter, an auditor (B) located at an apex of a triangle, other apexes thereof being occupied by said speaker systems (A,A), cannot hear the reproduced sound sufficiently especially in the middle and high tone ranges.
That is, the sound fields (C,C) of the middle and high pitch tones are shaped as shown at both sides of the auditor (B), thus being difficult to hear these ranges of the sound, and this tendency is even ,more apparent when the distance between the speaker systems (A,A-)
In order to eliminate the above described difficulty in the conventional speaker systems, the systems have been arranged as shown by chain lines-in the same drawing so that an angle is formed between the center lines, in plan view, of the speaker systems, so that an auditor can hear the middle and high pitch tone ranges in the reproduced sound more completely. However, such an arrangement of the speaker systems has reduced the utility of the room spaceand degraded th aesthetical feature of the same room. a
SUMMARY OF THEINVENTIONI Therefore, a primary object of the present invention is to provide a speaker system whereby theabove described drawback of the conventional speaker systems I be achieved by a speaker system wherein a sub-speaker device self-containing a speaker or speakers for middle and high pitch tone ranges is provided in such a manner that the directional angle of the sub-speaker device can be varied formed relative the baffle plate of a cabinet on which another speaker for the low tone range is mounted.
The nature, principle and the utility of the present invention will be better understood from the hereinafter described detailed description of the invention with respect to preferred embodiments thereof, when read in conjunction with the accompanying drawings, wherein like parts are designated by like reference numerals.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. la is a schematic diagram showing the sound field caused by a conventional speaker system;
FIG. lb showing that created by the speaker system according to the present invention;
FIG. 2 is a perspective view of a speaker system which constitutes a preferred embodiment of the present invention;
FIG. 3 is an enlarged sectional view taken along a vertical line passing through the center of FIG. 2;
FIG. 4 is a perspective -view of a speaker system which constitutes another embodiment of the invention; and
FIG. 5 is an enlarged sectional view taken along a vertical line passing through the center of the speaker system shown in FIG. 4.
DETAILED DESCRIPTION OF THE INVENTION Referring to FIG. la, there are indicated a set of speaker systems of a conventional type, each of the speaker systems A,A having a directional characteristic as shown by C in its sound field. From the hereinbefore described reason, this type of speaker systems must be arranged as shownin chain lines so that an auditor B positioned at an apex point of a triangle can hear the middle and high-pitch tone ranges sufficiently.
According to the present invention, the directional characteristic for the speaker or speakers creating the medium and high pitch tones is allowed to be deflected as designated by C in FIG. lb, whereby an auditor B located at an apex point of the triangle can hear the middle and the high pitch tone ranges as well as the low pitch tone range.
Referring to FIG. 2, there is indicated in a perspective view, a speaker system according to the present invention, and a sectional view showing the detailed construction is indicated in FIG. 3. In these Figures, a cabi net I for the speaker" system includes a baffle board 2 near the front surface of the cabinet 1, and the rear side of the baffle board 2, aligned with a lower tone passage hole 2a bored through the baffle board,. there is mounted a woofer 3. Extending through the baffle board 2 is a square or round hole 2b for mounting the speakers for the middle and high-pitchtone ranges. A freely rotatable frame body 4 is received within hole 2b in such a manner that the frame body 4 is pivotally supported by upper and lower shafts 4a so that the frame body 4 can be rotated around the vertical axis aligning with the shafts 4a. All ofthe above mentioned frame body 4 and the vertical shafts 4a project rearwardly within an auxiliary box 20, fixed to the baffle board 2. A speaker box 5 is supported within the frame body 4 by shafts 50 provided at the right and left sides thereof, so that the speaker box 5 is allowed to be rotated around the horizontally extended shafts 5a and a middle range speaker 6 and a tweeter 7 are included in the speaker box 5 mounted on a baffle 5b. As assembly consisting of the'bafile Sb and the middle range speaker and the tweeter 7 is hereinafter called an auxiliary speaker device. It should be noted that the auxiliary box 2c and the speaker box 5 are not necessary, and
these may be omitted whenever considered preferable.
With the above described construction of the speaker system, when the frame body 4 is rotated relative to the cabinet 1, the speakers 6 and 7 for middle and highpitch tone ranges can be directed to either of rightward or leftward direction against the cabinet I, and when the speaker box 5 is rotated relative to the frame body 4, the speakers for the middle and high-pitch tone ranges can be directed upwardly or downwardly relative to the cabinet 1. Thus it is apparent that thespeakers for the middle and high pitch tone ranges can be deflected to either right-and-left or up-and-down, by a universal mounting arrangement for the same.
Referring to FIGS. 4 and 5, there is illustrated a speaker system constituting another embodiment of the present invention. In this embodiment, the cabinet 1 includes a baffle board 2 as in the first embodiment, and through this baffle board 2 there is provided a hole 2a for passing lower pitch tone from speaker 3 and another circular hole 2b for supporting speakers for the middle and high-pitch tone ranges.
More specifically, along the circumferential edge of the circular hole 2b, ashort cylinder-8 is fixed. The inner surface 8a of the short cylinder 8 is formed into a'spherical configuration to receive a speaker box 9 for the middle and high-pitch tone ranges. The speaker box 9 is constructed in a form of a semi-sphere, and a baffle 9a for mounting speakers for the middle and high-pitch tone ranges 6 and 7 overlies the opening within semispherical speaker box 9. The combination of the baffle 9a and the speakers 6 and 7 forms an auxiliary speaker system similar to that of the first embodiment.
Since the speaker box 9 including the speakers for the middle and high-pitch tone ranges is slidably and freely rotatably received and moves in either of two directions within the short supporting cylinder 8, the direction of the speakers 6 and 7 can be adjusted in either of two right angle directions without fear of dropping out of the short supporting cylinder 8. I As is apparent from the above description, in either of the embodiments of the present invention, the speakers 6 and 7 for the middle and high-pitch tone ranges are mounted within a speaker box 5 and 9 which in turn is mounted freely rotatably in the baffle board 2 also mounting the woofer 3. Asa result, when the speaker box 5 or 9 only is rotated toward a desired directionwithout varying the orientation directionof the cabinet 1 as illustrated in "FIG. lb, the auditor B can hear the sound inthe middle and high-pitch tone ranges together with thelower tone range, regardless of the sharp directivity of the middle and high pitch tone ranges, whereby the auditory sensation 'is much .im-
Furthermore, in the case'of the second embodiment as shown in FIGS. 4 and 5, since the speaker box 9 accom'modating the speakers for the middle and highpitch ranges can be freely rotated in either of two right angle directions, a multi-cellular horn which has a predetermined mounting direction may also be equipped in the speaker box 9, and by rotating the speaker box 9 90, a vertical type cabinet may be horizontally oriented.
Although the invention has been described with respect to preferred embodiments thereof, it will be apparent to those skilled in the art that various modifications thereof may also be carried out without departing the scope of the invention as defined hereinbelow. For instance, the speakers for middle and high tone ranges as described in either of the embodiments may be substituted by a single speaker covering these ranges.
What is claimed is:
1. In a speaker system comprising two laterally spaced speaker assemblies, each speaker assembly being in the form of a cabinet having a baffle board on the front of said cabinet with said laterally spaced speaker assemblies generally facing an auditor at right angles to a plane defined by the baffle boards of respective cabinets with the auditor being spaced some distance therefrom, the improvement comprising;
a woofer mounted on the baffle board of each cabinet with the sound emanating therefrom generally at right angles to the baffle board,
an auxiliary speaker 'device in the form of a selfcontained speaker for at least the high-pitch tone range, and
means for mounting said device on each baffle board such that the angle of directivity between the auxiliary speaker device and the plane of the bafile board maybe varied universally to permit each auxiliary speaker to have its sound directed specifically towards said auditor.
i 2. The system of claim 1 wherein said mounting means comprises a universal mounting.
3. A speaker system as defined in claim 1 wherein said auxiliary speaker device mounted on the baffle board is supported thereon through vertical shafts and horizontal shafts so that the auxiliary speaker device can be rotated about verticaland horizontal axes.
'4. A speaker system as defined inclaim 1 wherein said auxiliary speaker device mounted on the baffle board is supported thereon through slidably contacting spherical surfaces so that the auxiliary speaker device can be rotated in mutually distinct right angle direc- I tions.