LOUDSPEAKER

HAUT-PARLEUR

English Abstract

A loudspeaker comprises an enclosure
(2) having a baffle (7) surrounding a drive unit
(4), characterised by means, e.g. columns or
pillars (3) mounting the drive unit (4) in the
enclosure (2) remote from the baffle (7).

French Abstract

Haut-parleur comprenant un boîtier (2) possédant un écran (7) entourant un excitateur (4) et caractérisé par des moyens, par exemple des colonnes ou des pilliers (3) permettant la fixation de l'excitateur (4) dans le boîtier (2) à distance du baffle acoustique (7).

Claims

CLAIMS
1. A loudspeaker comprising an enclosure (2) having a
baffle (7) surrounding a drive unit (4) characterised by
means (6) decoupling the baffle from the enclosure and by
means (3) mounting the drive unit (4) in the enclosure (2)
remote from the baffle (7) such that the drive unit (4) is
decoupled from the baffle (7).
2. A loudspeaker according to claim 1, characterised in
that the drive unit (4) is a mid range and/or low frequency
drive unit and by a high frequency drive unit (8) directly
mounted on the baffle (7).
3. A loudspeaker according to claim 1 or claim 2,
characterised by resilient sealing means (5) which seals
the drive unit to the baffle while maintaining one
decoupled from the other.
4. A loudspeaker according to any preceding claim,
characterised in that the enclosure (2) is of box-shape, in
that the baffle (7) forms the front of the enclosure, in
that the enclosure has a rear (9) opposing the front and in
that the drive unit (4) is mounted on the rear (9) of the
enclosure.
5. A loudspeaker according to claim 4, characterised in
that the drive unit (4) is mounted on at least one pillar
or column (3) projecting across the enclosure from its rear
(9).
6. A loudspeaker according to claim 6, characterised in
that the or each pillar or column (3) is tapered along its
length.

7. A loudspeaker according to claim 5 or claim 6,
characterised in that the or each pillar or column (3) is
integral with the rear (9) of the enclosure (2).
8. A loudspeaker according to any one of claims 2 to 7,
characterised in that the high frequency drive unit (8) is
mounted in position in the enclosure by entrapment between
the baffle (7) and one or more columns or pillars (3).
9. A loudspeaker according to any preceding claim,
characterised in that the baffle (7) is supported by one or
more pillars or columns (3).
10. A loudspeaker according to any preceding claim,
characterised in that the baffle (7) is sealed to, and
decoupled from, the enclosure (2) at their respective edges
(10,11) by a resilient seal (6).
11. A loudspeaker according to any preceding claim,
characterised in that the enclosure (2) and/or the baffle
(7) are moulded from a plastics material.

Description

woss/06397 21 6 5 3 2 7 pcTlGss4lol734
TITLE: LOUDSPEARER
DESCRIPTION
TECHNICAL FIELD
The invention relates to loudspeakers and more
particularly to loudspeakers of the kind comprising a box-
like enclosure, which may be cuboid in shape or otherwise,
housing one or more loudspeaker drive units.
It is an object of the invention to provide an
improved loudspeaker. More particularly it is an object of
the invention to provide a loudspeaker in which its baffle,
on which it is conventional to mount the drive units, is
de-coupled from at least one of the drive units.
Such de-coupling is desirable to prevent audible
distortions due to unintended exitation of the baffle or
due to unintended exitation of one drive unit, e.g. a
tweeter, by another drive unit e.g. a mid/bass range drive
unit, mounted on the same baffle.
De-coupling should not, however, be such as to hinder
the direct coupling of the drive units yia the enclosure to
the stand, shelf or floor on which the loudspeaker is
supported.
BACRGROUND ART
To avoid such problems it has been suggested to mount
the loudspeaker tweeter in a separate enclosure, which may
be physically separated from the associated enclosure
housing mid range and base drive units. Such an
arrangement involves additional expense in construction and
is not always possible for example for considerations of

WO 95/06397 PCTIGB94/01734
2165~7
available space.
DISCLOSURE OF lNv~NllON
Accordingly the present invention provides a
loudspeaker enclosure having a baffle surrounding a drive
unit, comprising means mounting the drive unit in the
enclosure remote from the baffle. The baffle may have a
drive unit, e.g. a tweeter, directly mounted thereon, with
the associated mid range and/or base drive unit(s) mounted
remotely from the baffle. Preferably the sole connection
between one drive unit and the baffle is by way of
resilient sealing means, e.g. a gasket.
Where the enclosure is a generally conventional cuboid
box-shape, one of the drive units may be mounted on the
rear surface of the enclosure. The said remotely mounted
drive unit may be mounted on one or more, preferably
several, pillars or columns projecting across the enclosure
from its rear. Preferably the pillars or columns are
tapered so that they have the effect of assisting in
breaking up s~An~ing waves within the enclosure. The
pillars or columns may be integral with the rear wall of
the enclosure and may, for example, be moulded from a
plastics material e.g. mica-filled polypropylene.
The tweeter may be mounted in position in the
enclosure by trapping it between the baffle and one or more
columns or pillars so that no separate fasteners are used.
At least one of the pillars or columns may also be
used to support the baffle.
BRIEF DESCRIPTION OF DRAWINGS

woss/06397 216 5 ~ ~ 7 pcTlGBs4lol734
The invention is diagrammatically illustrated, by way
of example, in the accompanying drawings in which:-
Figure 1 is an exploded sectional side view of aloudspeaker made in accordance with the present invention;
Figure 2 is a sectional side view of the loudspeaker
of Figure 1, and
Figure 3 shows, to a large scale, detail A of Figure
2.
BEST MODE FOR CARRYING OUT THE INVENTION
In the drawings a loudspeaker comprises an enclosure
consisting of a cuboid box-like cabinet 2 closed by a
baffle 7, both of which are moulded from a plastics
material such as mica-filled polypropylene. The cabinet is
formed internally with a series, e.g. four, of integral
tapered pillars or columns 3 which project across the
enclosure from its rear 9 and so that their free ends 12
are disposed in the vicinity of the front edge 11 of the
enclosure 2. The tapered shape of the pillars or columns
3 is useful in tending to break-up standing waves in the
enclosure. A low frequency drive unit 4 is mounted on the
columns 3 by fasteners, e.g. screws 16 so as to be
surrounded by, but spaced from, an aperture 13 in the
baffle 7. A resilient seal 5 is interposed between the
drive unit 4 and the aperture 13 in the baffle 7 so that
the drive unit 4 is decoupled from the baffle. Between the
respective edges 10,11 of the baffle 7 and the cabinet 2 is
interposed a resilient de-coupling seal 6 so that the
baffle is decoupled from the enclosure.

W095/06397 PCT/GBg4/01734
2165327
A high frequency drive unit 8 is directly mounted to
close an aperture 14 in the baffle 7 by means of fasteners,
e.g. screws 15.
An electronic cross-over network 1 is mounted on the
rear face 9 of the enclosure.
INDUSTRIAL APPLICABILITY
The arrangement described above not only produces a
loudspeaker in which the main drive unit is acoustically
de-coupled from the baffle but also has the advantage of
easy assembly. Thus with the cabinet laid on its back, the
speaker components can be dropped into place, perhaps
robotically. Also some testing of the loudspeaker can be
carried out before the baffle is attached.
Mounting the low frequency drive unit directly onto
the rear baffle of the enclosure ensures good coupling to
the seat of the cabinet i.e. a stand or shelf, which is
helpful in the extraction of the full dynamics of the
speaker.
Mounting the high frequency drive unit on the front
baffle ensures a rigid coupling to the stand or shelf.
Also the fact that the paths for the two drive units are
somewhat independent ensures at least one order of
isolation between the high frequency and low frequency
units while each is rigidly coupled to the floor.
With or without a high frequency drive unit, the
isolation of the low frequency drive unit from the front
baffle reduces box colouration due to acoustic radiation
from the baffle board.

WO 95/06397 2 ~ 6 5 ~ 2 7 PCT/GB94/01734
The loudspeaker described above can thus be of
improved performance compared to a speaker in which all of
the drive units are mounted on a common baffle.

Representative Drawing