GB2063618A

GB2063618A - Composite speaker system

Info

Publication number: GB2063618A
Application number: GB8029752A
Authority: GB
Original assignee: Pioneer Electronic Corp
Current assignee: Pioneer Corp
Priority date: 1979-09-14
Filing date: 1980-09-15
Publication date: 1981-06-03
Also published as: DE3034522C2; DE3034522A1; FR2465385B1; FR2465385A1; GB2063618B

Abstract

A composite speaker system for automotive vehicles in which a low- range speaker 1 is arranged to be mounted flush with a rear parcel shelf of a vehicle and a medium- and high-range speaker 3 is mounted above the low-range speaker having an angular orientation which is adjustable in a vertical plane, wherein the medium- and high-range speaker 3 can be directed into the passenger compartment without reflection from the rear window, the medium- and high-range speaker 3 being, in one example, rotatably mounted upon a grille frame 2 which is detachably disposed upon and engaged with the open surface of the low-range speaker 1, or alternatively first and second spacers extend from the centre of the low-range speaker through the grille frame for the low- range speaker. In this case, the medium- and high-range speaker is tiltably mounted upon the upper end of the spacers, the medium- and high-range speaker being also horizontally rotatable, or it may further be fixedly mounted in a direction towards the passenger compartment. <IMAGE>

Description

SPECIFICATION Composite speaker system for automotive vehicles The invention relates to a composite speaker system, and more particularly to a composite speaker system of the type in which a lowrange speaker unit is mounted flush with a rear parcel shelf of an automotive vehicle so that the open surface of the low-range speaker unit is directed upward.

If a conventional coaxial type composite speaker system, for example, a tri-axial speaker, is used in an automotive vehicle and is flush mounted on the rear parcel shelf, lowrange, medium-range and high-range sounds emanating from the speaker system are reflected by the inside surface of the rear window of the vehicle. This type of conventional composite speaker is advantageous in that high fidelity low-range sound is well reproduced since the trunk serves as a cabinet for the speaker system and the space defined by the rear parcel shelf and the rear window serves as a horn. It is, however, disadvantageous in that sound waves of the mediumrange and high-range sounds, which are the more important components for creating a stereophonic effect, are attenuated as a result of being reflected by the rear window.

This can be seen from the graph of Fig. 1 which indicates frequency versus sound pressure characteristic curves of a composite speaker system flush mounted on the rear parcel shelf of an automotive vehicle. The solid line I is a sound pressure characteristic curve of the medium-range and high-range sounds in the case of no reflection on the rear glass while the dotted line II illustrates the case of reflection. The conventional system is further disadvantageous in that the position of the sound image is not definite.

The primary object of the invention is to provide a composite speaker system for automotive vehicles in which there is a low-range speaker unit and a medium- and high-range speaker unit in which sound production is controlled to overcome the stated disadvantages when the speaker system is mounted flush on a rear parcel shelf of the vehicle.

According to the invention there is provided a speaker unit for an automotive vehicle comprising a low-range speaker and a mediumand high-range speaker, said low-range speaker and said medium- and high-range speakers being arranged so that the centre axis of said medium- and high-range speaker is different from that of said low-range speaker.

The invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is a graph showing frequency versus sound pressure characteristic curves of a composite speaker system; Figure 2 is an exploded perspective view showing a composite speaker system constructed in accordance with a firs, embodiment of the invention; Figure 3 is a partial cross-sectional view of the speaker system shown in Fig. 2; Figure 4 is a perspective view showing a composite speaker system constructed in accordance with a second embodiment of the invention; Figure 5 is a cross-sectional view showing a modification of the first embodiment shown in Fig. 2; Figure 6 is an exploded and partial crosssectional view showing a part of the modification shown in Fig. 5;; Figure 7 is a cross-sectional view showing a composite speaker system constructed in accordance with a third embodiment of the invention; Figure 8 is a perspective view of the speaker system of Fig. 7; and Figure 9 is a diagram showing the distribution of sound pressure in the passenger compartment of a vehicle employing a speaker system of the invention.

A first preferred embodiment of the invention will be described in detail with reference to the accompanying drawings.

Fig. 2 is an exploded perspective view showing a composite speaker system in which reference numeral 1 designates a speaker unit for reproducing low-range sound and 2 an attachment member made of metal or plastic material which is attachable to and detachable from an outer peripheral portion 5a of a frame member 5 for the speaker unit 1. The attachment member 2 is provided for the purpose of protecting the open surface of the speaker unit 1 and also for purpose of enhancing the appearance of the unit. The attachment member 2 includes an annular ring portion A, a hub portion B and spokes C which radially extend from the hub portion B to the inside wall of the annular ring portion A. A metal grill (not shown) extends over the surface of the attachment member 2.Reference numeral 3 designates a speaker unit for reproducing medium- and high-range Fnund which is mounted in a casing. The speaker unit 3 is coupled to the hub portion B of the attachment member 2.

The speaker units 1 and 3 are arranged so that their sound radiating directions are different. For example, the. speaker unit 3 may be arranged so that its sound radiating direction is perpendicular to that of the speaker unit 1.

The sound radiating direction of the speaker unit 3 may be varied in the vertical direction by adjustment of a knob 4. Specifically, upon loosening the knob 4, the speaker unit 3 can be rotated about the knob 4 whereas by tightening the knob 4, the speaker unit 3 can be secured at any possible position thereof. It is of course possible to employ another type of adjusting device for vertically adjusting the speaker unit 3.

Referring to Fig. 3, which is a partial sectional view of the speaker system shown in Fig. 2, an edge portion 7, which acts as a suspension for a diaphragm 6, is fixed to the outer peripheral portion 5a of the frame member 5 with a packing 8. A pair of female terminals 9a and 9b is provided in the packing 8 which pass through the outer peripheral portion 5a of the frame member 5. The female terminals 9a and 9b include a terminal member 11 made of conductive material extending partially into a tubular member 10 made of insulating material. A lead wire 1 3 with one end connected to a junction terminal 1 2 is connected at the other end to the terminal member 11.Reference numeral 1 4 designates a wire connected between the repeater terminal 1 2 and the diaphragm 6 and 1 5 a lead wire connected at one end to the repeater terminal 12 and at the other end to a speaker terminal provided in an amplifier (not shown).

Corresponding to the pair of female terminals 9a and 9b, a pair of male terminals 1 6a and 1 6b is mounted on the back portion of the annular ring portion A. It is necessary that the male terminals 1 6a and 1 6b be electrically insulated from the annular ring portion A. Electrical insulation can be omitted if the attachment member 2 is made of insulating material such as plastic. Connected to the male terminals 1 6a and 1 6b are lead wires 1 7a and 1 7b which are coupled at their other ends to a network (not shown) located in the interior of the casing of the speaker unit 3.

In the above-described embodiment, while the female terminals 9a and 9b are mounted on the frame member 5 and the male terminals 1 6a and 1 6b are mounted on the attachment member 2, it is of course possible to mount the female terminals and the male terminals in the opposite positions. It is further possible to employ terminals 9a, 9b, 1 6a and 1 6b of different configurations from those described above insofar as the same function is achieved.

It is possible to make the medium- and high-range speaker unit 3 rotatable to vary the angle of its center axis in a vertical plane with respect to the center axis of said low-range speaker. Examples of such a structure will be described. In a first example, the speaker unit 3 is mounted on the hub portion B so as not to move horizontally and the relative position of the attachment member 2 with respect to the open surface of the speaker unit 1 is changed. To this end, plural pairs of male terminals 1 6a and 1 6b are provided along the annular portion A at predetermined intervals so that a single pair of female terminals 9a and 9b on the outer peripheral portion 5a can engage with either one of a pair of the male terminals 1 6a and 16b.Plural pairs of lead wires are also provided at the edge portion of the annular ring portion A connected in parallel with one another. In this example, the change of the relative position of the speaker unit 3 on the horizontal plane is carried out in steps.

A second embodiment of a speaker system will be described with reference to Figs. 5 and 6 in which the speaker unit 3 is designed to be rotatable in the horizontal direction as well as in a vertical plane. Fig. 5 is a crosssectional view showing the second embodiment of a composite speaker system according to the invention. In this figure, reference nunieral 1 9 designates a magnetic circuit driver unit for the low-range speaker unit 1 which is made up of a magnet 1 9a, a yoke 19b, a pole 1 9c and a plate 19d. A central portion of the diaphragm 6 of the low-range speaker unit 1 is attached to a voice coil 20.

A first damper 21 is provided extending between the diaphragm 6 from slightly above the voice coil 20 and the frame 5. The edge portion 7 of the diaphragm 6 is fixed to the outer peripheral portion 5a of the frame 5 which is constructed as described with reference to Fig. 3.

Reference numeral 22 designates a first spacer made of insulating material. As shown in Fig. 6, the first spacer 22 is integrally formed with a larger-diameter cylindrical member 23 and a smaller-diameter cylindrical member 24 with the smaller-diameter member 24 disposed above the larger-diameter member 23. A female thread 23a is formed in the center of the bottom surface of the largerdiameter cylindrical member 23. The first spacer 22 is fixedly disposed above the center pole 1 9c by threaded engagement of a male thread 26, formed on and extending upwardly from the center pole 19c, and the female thread 23a. A second damper 27 is connected between a stepped portion 25 of the spacer 22 and the diaphragm 6 in the usual fashion. The smaller-diameter cylindrical member 24 has a tapered surface 28a at the upper portion thereof and a stepped lower surface 28b acting as a stop. A pair of conductive plates 29 and 30 extend through the body portion of the smaller-diameter cylindrical member 27 with first ends 29b and 30b projecting outwardly from the lower side portion of the cylindrical member 24 while the second ends 29a and 30a project from the top surface 24a of the cylindrical member 24 and are bent towards the center of the cylindrical member 24 confronting each other. The projecting and bent portions 29a and 30a of the conductive plates 29 and 30 provide a resilient force in the upward direction. The outwardly projecting portions of the conductive plates 29 and 30 act as terminals as will be described below.A guide hole 24b having a predetermined depth is formed at the center of the upper surface 24a of the smallerdiameter cylindrical member 24. An arcshaped guide groove 24c is coaxially formed in the upper surface 24a of the cylindrical member 24.

Reference numeral 31 designates a second spacer made of insulating material rotatably engaged with the first spacer 22. The lower portion of the second spacer 31 is cylindrical.

The inner wall of the cylindrical portion of the second spacer 31 is tapered so as to fittingly engage the tapered surface 28a of the first spacer 22. A stepped upper surface 22 is formed in the inner wall of the second spacer 31 with the stepped upper surface 22 abutting the stepped lower surface 28b formed in the first spacer 22 when the first and the second spacers are engaged. A guide pin 34a projects downwardly from the center of the lower surface 34b loosely engaging the aformentioned guide hole 24b. Arc-shapeSçon- tact pieces 36 and 37 are mounted separately on the surface 34b which contact the bent conductive plates 29a and 30a, respectively.

A guide pin 38 is also provided in the surface 34b which is adapted to engage and slidably move along the guide groove 24c formed in the upper surface 24a of the first spacer 22.

Lead wires 36a and 37a connected to the contact pieces 36 and 37 pass through the interior of the second spacer 31 and exit from a chamber 26 above the second spacer 31.

To the lower surface of the casing 39 which holds the medium- and high-range speaker unit 3, a pair of legs 40a and 40b are secured which are inserted into the chamber 26 and is tightened by a tightening screw (not shown) rigidly coupled to the knob 4 so that the casing 39 is freely rotatable in the vertical direction about the tightening screw. The lead wires (not shown) which extend from the voice coil of the speaker unit 3 pass through an opening 39a in the lower surface of the casing 39 and an opening 41a in the upper surface of the chamber 41 and are connected to the lead wires 36a and 37a. The terminals 29b and 30b which project outwardly from the lower side portion of the smaller-diameter cylinder member 24 are connected in parallel with lead wires (not shown) connected to the voice coil 20.

The mounting of the speaker unit 3 above the position of the speaker unit 1 will next be described. The second spacer 31 extends downwardly from the central opening of the grills C engaging the first spacer 22. The lower circumferential edge 31a of the second spacer 31 contacts the tapered surface 28a when the second spacer 31 is downwardly inserted. When the second spacer 31 is inserted downwardly, the diameter of the lower circumferential edge 31a is enlarged due to the forced contact with the tapered surface 28a of the first spacer 22. When the lower circumferential edge 31 a is further inserted, the stepped lower surface 28b is brought into abutment with the stepped upper surface of the first spacer 22. Then, the diameter of the lower circumferential edge 31 a is restored to the original size.In the abutted condition, the guide hole 24b formed in the upper surface 24a of the first spacer 22 receives the guide pin 34a provided in the second spacer 31.

Further, the guide pin 38 is inserted into the guide groove 24c and is movable therealong.

Consequently, the second spacer 31 is attached to the first spacer 22 but is freely rotatable. The second spacer 31 is not detached from the first spacer 22 due to the abutment of the stepped surfaces 28a and 28b. In this condition, the bent portions 29a and 30a of the metal plates 29 and 30 and the contact pieces 36 and 37 are electrically connected due to the upward resilient force of the bent portions 29a and 30a.

Fig. 4 is a perspective view showing an alternative speaker system. This embodiment is similar to the embodiment shown in Fig. 2 with the exception that the speaker unit for the medium- and high-range sound is separated into individual units, specifically, a medium-range speaker 1 8 and a high-range speaker 18' positioned side-by-side in the casing. It is possible to modify this embodiment by arranging the high-range and medium-range speakers vertically.

A preferred embodiment will be described with reference to Figs. 7-9.

Referring to Fig. 7, reference numeral 1 designates a woofer or low-range unit in which one end of a cone type diaphragm 6 is attached to a voice coil 20 in a driver unit 1 9 with the outer peripheral edge portion 7 of the diaphragm 6 attached to the end of a frame 5 through an interposed gasket 46. Fig.

8 shows a perspective view of the speaker unit of Fig. 7. A holder 43 for holding or supporting a tweeter or medium- and highrange speaker unit 42 is attached to the frame 5. The lower portion 51 of the holder 43 is rigidly attached to the frame 5. A threaded hole 51a which receives a mounting bolt is formed in the center of the lower portion 51.

The intermediate portion 52 of the holder 43 is inclined so that its axis intersects the central axis of the low-range unit 1. The upper portion 53 of the holder 43, which holds the medium- and high-range unit 42, has a through hole 53a formed therein to allow a fixing bolt 54 to be inserted into a threaded hole formed in the upper portion 53 of the holder 43.

The fixing bolt 54 is engaged with a threaded hole 49b formed in a yoke 49a which constitutes a driver unit 49 for the medium-and high-range speaker unit 42. A grill 55 is provided over the front surface of the unit 42. In front of the medium- and highrange unit 42, a diffuser 56 is attached. A grill frame 47 is detachably coupled to the periphery of the front surface of the low-range unit 1. A grill 48 is provided in the grill frame 47. The grill 48, if desired, can be made integral with, the grill 55.

Next, an example of a process for fabricating the speaker unit of this embodiment of the invention will be briefly described. Firstly, the holder 43 and the low-range unit 1 are combined together in such a way that a hole formed in the end of the frame 5, a hole in the gasket 46 and the hole 51a formed in the lower portion of the holder 43 are aligned to permit a bolt 51 be screwed into the threaded hole 51 a through the former two holes. Then, the holder 43 and the medium- and highrange unit 42 are combined and coupled together by screwing the fixing bolt 54 into the hole 53a and the hole 49b formed in the yoke 49a.

When the low-range unit 1 is attached to the rear parcel shelf T, it is necessary that the axis of the medium- and high-range speaker unit 42 be directed to the passenger compartment. The angle of inclination of the intermediate portion 52 of the holder 43 is determined according to the configuration of the low-range unit 1 and the configuration and the slope of the rear parcel shelf T.

In this embodiment, the slope of the axial line of the medium- and high-range unit 42 forms an angle of approximately 30 degrees with respect to the rear parcel shelf T. The medium- and high-range sound is radiated from a diffuser 31 attached to the front portion of the medium- and high-range unit 42.

Shown in Fig. 8 is the distribution of the sound pressure produced by the speaker unit according to this embodiment of the invention. As can be appreciated from this figure, the region to which the high-range sound is delivered is situated in the center of the region to which the low-range sound is delivered and thus the high-range and low-range sounds are reproduced with their sound images coinciding.

As is apparent from the foregoing description, since the low-range speaker unit and the medium- and high-range unit are arranged so that the central axes of the speaker units are not parallel to each other but intersect with each other, the drawbacks accompanying the conventional speaker unit are eliminated. Specifically, with the use of the speaker unit a good stereophonic effect is obtained because the medium- and high-range sound is directly radiated into the passenger compartment. Further, since the open surfaces of the mediumand high-range and the low-range speaker units are covered with an integral grill, the number of parts used in fabricating the speaker unit is reduced and mass production can be effectively carried out.

Claims

1. A speaker unit for an automotive vehicle comprising a low-range speaker and a medium- and high-range speaker, said lowrange speaker and said medium- and highrange speakers being arranged so that the centre axis of said medium- and high-range speaker is different from that of said lowrange speaker.

2. A speaker unit of claim 1 wherein said low-range speaker and said medium- and high-range speaker are fixedly arranged with their central axes intersecting in a side section and a grill frame and grill members are mounted in said grill frame, open surfaces of said low-range and medium- and high-range speakers being covered with said grill members, and said grill frame being detachably engaged with the open surface of said lowrange speaker.

3. A speaker unit of claim 2 further having a sound diffuser mounted adjacent said medium- and high-range speaker.

4. A speaker unit of claim 1 comprising a low-range speaker having a frame to which an outer peripheral edge of a diaphragm of said low-range speaker is attached, said frame being adapted to be flush mounted to a rear parcel shelf of an automotive vehicle, a holder rigidly mounted upon a rear edge of said frame, said holder being adapted to support said medium- and high-range speaker having a central axis directed towards a passenger compartment of said vehicle; a grill frame detachably coupled around said low-range speaker; and a grill supported by said grill frame covering said low-range and said medium- and high-range speakers.

5. A speaker unit of claim 4 including a sound diffuser positioned over the open surface of said medium- and high-range speaker.

6. A speaker unit of claim 1 further characterized in that the angular orientation of the centre axis of said medium- and high-range speaker is changeable in a vertical plane with respect to the centre axis of said low-range speaker and a grill frame and a grill member mounted in said grill frame covers at least portions of open surfaces of said low-range speaker, and said grill frame is detachably engaged with the open surface of said lowrange speaker.

7. A speaker unit of claim 6 wherein said medium- and high-range speaker is mounted upon said grill frame.

8. A speaker unit of claim 7 wherein said grill frame comprises an outer annular ring, a centre hub portion and a plurality of spokes extending between said annular ring and said hub portion, said medium- and high-range speaker being coupled to said hub portion.

9. A speaker unit of claim 8 wherein a first pair of terminals are fixedly mounted upon an outer peripheral portion of a frame member of said low-range speaker and a second pair of terminals are rigidly secured to said grill frame, said first and second pairs of terminals being connectable together when said grill frame is engaged with the open surface of said low-range speaker, said first pair of terminals being coupled to a void coil of said low-range speaker and said second pair of terminals being coupled to a voice coil of said medium- and high-range speaker.

10. A speaker unit of claim 9 wherein each terminal of said first pair of terminals comprises an insulating tubular member extending through said frame member and an electrically conductive member extending at least partially into said tubular member.

11. A speaker unit of any of claims 1 to 10 in which said medium- and high-range speaker comprises a single speaker.

12. A speaker unit of any of claim 1 to 10 in which medium- and high-range speaker comprises separate medium-range and highrange speakers.

1 3. A speaker unit of any of claims 6 to 1 2 wherein the medium- and high-range speaker is horizontally rotatable at least through a predetermined angle.

14. A speaker unit of claim 6 in which mounting means for said medium- and highrange speaker comprises a first spacer having a smaller-diameter portion and a larger diameter portion, said larger-diameter portion being rigidly secured to a frame of said low-range speaker and at least a portion of said largerdiameter portion being surrounded by a voice coil of said low-range speaker, a damper member having an outer edge coupled to a cone of said low-range speaker and having an inner edge coupled to said larger-diameter portion at the junction with said smaller-diameter portion, said smaller-diameter portion having an upper tapered surface, first and second conductors extending through portions of said smaller-diameter portion and forming contacts upon said upper surface; a second spacer having a lower cylindrical portion tapered to fittingly engage said upper surface of said first spacer, third and fourth conductors extending through a portion of said second spacer and forming contacts disposed to mate with said contacts formed by said first and second conductors; and means for tiltably mounting said medium- and high-range speaker upon an upper portion of said second spacer, a voice coil of said medium- and highrange speaker being coupled to said third and fourth conductors.

1 5. A speaker unit of claim 14 wherein said second spacer has a first guide pin extending downwardly from the centre thereof to mate with a guide hole formed in said first spacer.

1 6. A speaker unit of claim 1 5 including a second guide pin rigidly coupled at an offcentre position of said second spacer and being slidably disposed in an arc-shaped guide groove coaxially formed in said upper surface of said first spacer.

1 7. A speaker unit substantially as hereinbefore described with reference to and as shown in Figs. 2 and 3 of the accompanying drawing.

1 8. A speaker unit substantially as hereinbefore described with reference to and as shown in Fig. 4 of the accompanying drawing.

1 9. A speaker unit substantially as hereinbefore described with reference to and as shown in Figs. 5 and 6 of the accompanying drawing.

20. A speaker unit substatially as hereinbefore described with reference to and as shown in Figs. 7 and 8 of the accompanying drawing.