GB2212694A

GB2212694A - Speaker

Info

Publication number: GB2212694A
Application number: GB8727343A
Authority: GB
Inventors: Robert Alfred Webb
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-11-21
Filing date: 1987-11-21
Publication date: 1989-07-26
Also published as: GB8727343D0

Abstract

The invention relates to speakers for producing high quality musical sound in which a first low frequency transducer (16) is mounted in a box (12) facing upwardly and a frame (17) mounts a second higher frequency transducer (23) above the first transducer and spaced from the top thereof such that sounds from the first transducer can be transmitted sideways from the space between the transducers. The speaker is designed to be mounted on the floor at lower level than the ears of a listener. <IMAGE>

Description

SPEAKER This invention relates to speakers and more particularly to speakers for producing high quality musical sound as opposed to speakers used for less high quality sound in public places or for public address systems.

Conventional such speakers comprise one or more transducers for producing sound from an electrical signal mounted in a box or cabinet. Where there is more than one transducer these are mounted in the box side by side or one above the other in substantially the same plane and all facing forwards, the front of the box being formed with an aperture covered by a grill cloth.

The speaker is normally tailored to transmit the sound directionally forwardly along the axis of the transducer or within an acute angle less than 300 of this axis. This is particularly true for speakers including high quality transducers for producing hi-fi musical sound.

Most such speakers are mounted with the axis horizontal or at only a small angle (less than 100) to the horizontal. This means that the listener will only get the best sound when positioned on or near the axis of the speaker and where one or more speakers is operating simultaneously the listener needs to be on or near the axis of each speaker.

Even when the listener is ideally located relative to the speaker or speakers the reflections of sounds around the room will cause deterioration from the ideal unless the room is specially designed or treated.

An object of the invention is to provide a speaker designed for off axis listening. Accordingly, the invention provides a speaker having high and low frequency transducers both facing upwardly and with the high frequency transducer mounted above and spaced from the low frequency transducer.

Preferably, a speaker comprises a box in which a first low frequency transducer is mounted facing upwardly, and frame means mounting a second higher frequency transducer above the first transducer and spaced from the top thereof such that sounds from the first transducer can be transmitted sideways from the space between the transducers.

Such a speaker can include two high quality transducers which will not substantially interfere with one another accoustically (except to a listener spaced immediately thereabove) and will produce sound which is less directionally transmitted than conventional high quality speakers. The speaker is designed to stand on the ground so that the listener's ears will be at a higher level than the speaker.

With advantage the second speaker will be spaced at least 60 mm and preferably 80 mm or more above the top of the first speaker.

Preferably the box has at least five litres of space behind the first transducer.

The spare between the transducers is preferably surrounded by a grill cloth and a grill cloth extends over the second transducer.

The frame means may comprise pillars at the corners of the box supporting a tray which in turn supports the second transducer.

Preferably an outlet for electrical wires is provided in a cut away portion of the base of the box.

One embodiment of speaker, in accordance with the invention, will now be described by way of example only, with reference to the accompanying diagramatic drawings of which:- Figure 1 is a side view of a speaker, and Figure 2 s a diagramatical perspective view of the parts of the speaker of Figure 1 in unassembled form Figure 3 is a top plan view of the speaker and Figure 4 is an underneath plan view The speaker comprises a parallelopiped box 12 having a base portion 13 resting on the ground and a circular aperture 14 its top 15. Mounted in.the aperture is a low frequency (base), high quality transducer 16 of known form which faces upwardly.A frame 17 of substantially the same horizontal dimensions as the box has four corner pillars 18 connected by struts 20 and is secured by screws or the like to the top of the box and supports a tray 21 having an upstanding rim 22.

The tray is secured to the frame by screws or the like and mounts a high frequency (tweeter), high quality, transducer 23 of known form. The tray is preferably mounted at least 60 mm and preferably 80 mm or more above the top of the box.

A grill cloth 24 extends around the frame 17 and another 25 over the top of the tray 21.

A corner of the base portion is cut away and an outlet 26 for electrical wires is provided on the diagonal face 27.

I have found that because the frequencies below about 200 Hert are not particularly directional but depend on movement of air these frequencies are not affected by the tray above the base transducer and because the middle range of frequencies tend to be omitted from the base transducer at an angle to its vertical axis these frequencies can also be omitted without interference from the tray provided the space between the transducers is sufficient. The cross over point at which the tweeter takes over from the base transducer is preferably 3 KiloHertz + or - 109

Claims

CLAIMS 1 A speaker unit designed for off-access listening comprising high and low frequency transducers both facing upwardly and with the high frequency transducer mounted above and spaced fro the low frequency transducer
2 A speaker unit designec for off-access listening comprising a box in which a first low frequency transducer is mounte@ facing upwardly, frame means mounting a second higher frequency transducer spove the first transduce@ and sp@@ec from the top there of such that so@nd fron the finet transducer can be transmitted sidewers from the space @etween the transducers.
3 A speaker unit according to claim 2 in unich the higher frequenc@ transducer is space@ et lesst @@ mm above the lower frequency transducer.
4 A speaker unit according to claim 1 or claim 2 in which the higher frequency transducer 15 m@@@tes a t least 80 mm above the lower frequency transducer
5 A speaker unit according to claim 2 or any claim dependent thereon in which the box has at least five litres of space below ow the first transducer.
6 A speaker unit accordinc to any of the preceding claims in which the space between the transduce@@ 15 surroundec by a grill cloth.
7 A speaker unit accorcing to any of the preceding claims in which a grill cloth extends over the second transducer.
8 A speaker unit according to claim 2 or any claim dependent thereon in which the frame means comprises pillars extending upwards from the corners of the box and supporting a tray which in turn supports the second transducer.
9 A speaker unit according to any of claims 1 to 8 in which the transducers are of high quality and ln which the higher fr equericy t rarisducer takes over t h the lower frequenc@ transducer at 3 KiloHertz + or - 10%.
10 A speaker unit substantially as described herein with reference to or as illustrated in the accompanying orawings.

11 system for producing high quality musical sound including one or more speakers according to the claims 1 to 10, in which the speakers are mounted on the floor