GB2463924A

GB2463924A - Wireless table-top conference system uses Balanced Mode loudspeaker

Info

Publication number: GB2463924A
Application number: GB0811700A
Authority: GB
Inventors: Allan Read
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-06-26
Filing date: 2008-06-26
Publication date: 2010-04-07
Also published as: GB0811700D0

Abstract

A tabletop wireless conference or congress system comprises at least one audio loudspeaker enclosure which includes a single unconventional loudspeaker 4 with a very wide audio dispersion pattern e.g. a balanced mode radiator or a loudspeaker with an inverted cone, mounted facing upwards, together with a wireless audio receiver 7, amplifier 6, battery pack 8 and without external connecting wires. This enables it to be placed in the centre of a table around which anyone seated will be within the listening area (5, fig 2) without the need for additional baffles or shaped mouldings to direct the sound. The audio signal is received from an external master audio transmitter module (3, fig 2). Any number of wireless loudspeaker enclosures can then be employed within a given area providing they all fall within range of the master transmitter. The enclosure 4 may also include a microphone (10, fig 4).

Description

A Tabletop Wireless Audio Loudspeaker This invention relates to an upward facing, tabletop loudspeaker with an integral rechargeable power pack, amplifier and wireless audio receiver.

Vocal presentations are often relayed by means of a wireless audio transmitter to a receiver in a portable amplified loudspeaker enclosure. The loudspeaker then projects the sound forward with sufficient volume to reach the furthest parts of the audience. Often, a second loudspeaker is attached to the receiving loudspeaker by means of a cable to help distribute the sound even more widely. In order to provide sufficient volume and to power the conventional RE receivers and any music players, substantial battery packs have to be on board, and the resulting portable' enclosure is often far heavier than its wired counterparts.

In the majority of cases, and by nature of how a conventional loudspeaker projects sound forward in a cone shaped pattern, the loudspeaker is mounted vertically, usually on a stand pointing towards the audience.

Often, if an audience is seated around several tables, it is possible to position multiple smaller loudspeakers pointing down towards the audience, for example in a ceiling cavity. However, the problem is that these loudspeakers are permanent installations, wired together and usually employing some kind of shaped moulding to disperse the sound widely enough to reach all of the listeners below.

It is known to incorporate a small low powered conventional loudspeaker pointing downwards in a tabletop enclosure with a conventional wireless receiver, amplifier and battery pack. However to accommodate all of these parts and some form of shaped moulding or baffle to deflect the sound in a 3600 pattern around the table still requires a fairly obtrusive enclosure.

To overcome these problems the present invention proposes that a tabletop wireless audio loudspeaker enclosure, includes a single unconventional loudspeaker with a very wide audio dispersion pattern, mounted facing upwards, together with a wireless audio receiver, amplifier, battery pack and without external connecting wires, enabling it to be placed in the centre of a table around which anyone seated will be within the listening area without the need for additional baffles or shaped mouldings to direct the sound.

The unconventional loudspeaker would preferably be of a type called a Balanced Mode Radiator which has advantages over a conventional cone loudspeaker, in that when mounted facing upwards, it is capable of very wide audio dispersion in an almost half-spherical listening pattern without the use of additional baffles or shaped mouldings. The wireless audio receiver module would generate an audio signal transmitted from a matching external master transmitter module. Any number of wireless loudspeaker enclosures can then be employed within a given area providing they all fall within range of the master transmitter. The advantage of this is that less volume is required from each loudspeaker enclosure to provide a balanced, undistorted pattern of sound to all parts of the audience.

The invention will now be described solely by way of example and with reference to the accompanying drawings in which: Figure 1 shows a conventional pistonic cone speaker in a portable, battery powered enclosure and positioned on a stand to project sound from the front to the rear of the audience; and Figure 2 shows vocal and recorded music distributed via a multi-channel wireless transmitter to multiple wireless receivers in compact tabletop enclosures also containing a battery pack, amplifier and a Balanced Mode Radiator loudspeaker according to the invention; and Figure 3 shows the tabletop enclosure in close up and details the internal parts and operating position of the Balanced Mode Radiator loudspeaker plus an optional moulded extension with predominantly open sides.

Figure 4 shows an alternative embodiment in which a microphone with a very wide pick-up pattern (half-spherical) is mounted in the top of a moulded extension wired to an additional transmitter inside the enclosure.

Figure 5 shows the alternative embodiment in figure 4 in multiple use with additional microphone receivers providing inputs to the master transmitter.

In Figure 2, a live vocal (1) or recorded audio signal (2) provides the input to a very small form factor l5ch audio transmitter module (3), transmitting to any number of compatible l5ch receiver modules (7) within range that are tuned to the same channel as the transmitter. These modules preferably operate in the License free European harmonised 863 -865 MHz band -typically those manufactured by Circuit Design Japan. In addition to offering a frequency range sufficient for voice transmission, the compander noise reduction system has a wide dynamic range, enabling transmission of clear audio signals. As embedded devices, they include nearly all the parts necessary for audio transmission in a small shielding case, making it possible to develop audio transmission equipment in a short time.

Each audio receiver module is integrated into low profile tabletop enclosure together with a rechargeable battery pack, class-d amplifier (6) and a Balanced Mode Radiator loudspeaker (4), this allows the enclosure to operate without any connecting wires and thus be placed in the centre of a table.

The Balanced Mode Radiator as developed by Graham Bank of Deben Acoustics is a modal loudspeaker and uses a flat circular panel but built into a chassis much like a conventional loudspeaker. The application of BMR technology provides a flat full range on axis frequency response combined with very wide directivity.

When the Balanced Mode Radiator is mounted facing upwards according to the invention, this wide directivity provides a clear audio signal to anyone sitting around the table and thus within the listening area (5) without the need for additional mould ngs or baffles.

An alternative embodiment of the invention could use a loudspeaker with an inverted cone which, while not having the same wide directivity of the Balanced Mode Radiator, has sufficiently wide directivity to enable the invention to work without the need for additional mouldings or baffles.

In Figure 3 the tabletop enclosure is shown in close-up, indicating the position of the Balanced Mode Radiator (4) and the other components required to enable the invention to operate without external connecting wires.

Preferably, an integrated class-d, low voltage, low current amplifier (6) would be used, with sufficient power to drive a small diameter Balanced Mode Radiator, generating very little heat and allowing the use of a small, very low profile enclosure.

Preferably, the amplifier would be mounted on a specifically designed PCB together with a volume control, additional electronics and a multi-channel, small, low current, wireless audio receiver module (7) with a wide dynamic range, enabling reception of clear audio signals from a remote, compatible transmitter (3) as described in Figure 2.

The use of small form factor, low voltage, low current consumption components -typically less than 200mA in total, would leave additional space in the enclosure for a compact, high capacity, rechargeable battery pack (8).

Preferably this would incorporate an integral charger circuit with features such as overcharge protection, thermal protection and low voltage cut off. This would provide for a truly wire free, portable enclosure with local volume control, capable of providing clear audio performance around a table for several hours before recharging.

An optional moulded extension with predominantly open sides (9), could be added to the enclosure to deter listeners from inadvertently placing objects on the surface of the loudspeaker or on a banqueting table could be specifically designed to support a small floral arrangement above the loudspeaker.

Figure 4 shows an alternative embodiment of the invention in which a microphone with a very wide pick-up pattern (half-spherical) is mounted in the top of a moulded extension with predominantly open sides (9). This is wired to an additional wireless audio transmitter (3) mounted on the PCB within the enclosure then: In Figure 5 a corresponding wireless audio receiver module (7) is mounted alongside the original master transmitter (3) creating a wireless audio hub (11). Each additional transmitter and receiver pair would be tuned to a different spare channel in the available frequency range with each microphone signal mixed back to the master transmitter (3).

The invention is then two-way, allowing any person sitting around a table with a tabletop enclosure containing a microphone to respond to the presenter and be heard at each table with other tabletop enclosures, the maximum being governed by the number of free channels available on the wireless modules.

Important uses of the invention in all its embodiments are as follows: 1. Conference presentation or debating system.

2. Event presentation system particularly in situations where wiring and power is problematic such as in marquees for wedding speeches, award ceremonies, sporting events.

3. Presentation in historic buildings where hard wiring is subject to planning restrictions or architecturally sensitive.

4. Presentation or information in schools or colleges where students are required to work in groups around a table or in exam areas.

5. At outdoor events for presentation, or for consumer background music.

Claims

Claims A tabletop wireless audio loudspeaker enclosure, including a single unconventional loudspeaker with a very wide audio dispersion pattern, mounted facing upwards (4), together with a wireless audio receiver (7), amplifier (6), battery pack (8) and without external connecting wires, enabling it to be placed in the centre of a table around which anyone seated will be within the listening area (5) without the need for additional baffles or shaped mouldings to direct the sound.
2. A tabletop wireless audio loudspeaker enclosure according to claim 1, in which the single unconventional loudspeaker (4) is of the type known as a Balanced Mode Radiator.
3. A tabletop wireless audio loudspeaker enclosure according to claim 1, in which the single unconventional loudspeaker (4) is of the type employing an inverted cone.
4. Tabletop wireless audio loudspeaker enclosures according to claim 1,2 and 3 where the audio signal is transmitted from an external, very small form factor l5ch or more master audio transmitter module (3) to any number of compatible I 5ch or more receiver modules (7) within range, that are tuned to the same channel as the transmitter and housed within the wireless audio enclosures.
5. A tabletop wireless audio loudspeaker enclosure according to claim 1,2,3 and 4 where the audio signal is amplified by an integrated amplifier (6), with sufficient power to drive a small diameter Balanced Mode Radiator or inverted cone loudspeaker (4), generating very little heat and allowing the use of a small, very low profile enclosure.
6. A tabletop wireless audio loudspeaker enclosure according to claims 1,2,3,4 and 5 where the use of small form factor, low voltage, low current consumption components, would leave additional space in the enclosure for a compact, high capacity, rechargeable battery pack (8).
7. A tabletop wireless audio loudspeaker enclosure according to claims 1,2,3,4,5 and 6 where a microphone (figure 4/10) with a very wide pick-up pattern (half-spherical) is added to the enclosure, wired to an additional wireless audio transmitter (figure 4/3) mounted on the PCB within the enclosure and a corresponding additional external wireless audio receiver module (figure 5/7) is mounted alongside and input to the original master transmitter (figure 5/3), creating a wireless audio hub (figure 5/11) and allowing any person sitting around a table with a tabletop enclosure containing a microphone to respond to the presenter and be heard at each table with other tabletop enclosures.
8. A tabletop wireless audio loudspeaker enclosure according to claim 1, where an optional moulded extension with predominantly open sides (9) could be added to the enclosure to deter listeners from inadvertently placing objects on the surface of the loudspeaker or on a banqueting table could be specifically designed to support a small floral arrangement above the loudspeaker.