GB2425029A

GB2425029A - Surround sound system

Info

Publication number: GB2425029A
Application number: GB0507177A
Authority: GB
Inventors: Wen-Chi Hung; An-Sheng Chang
Original assignee: Giga Byte Technology Co Ltd
Current assignee: Giga Byte Technology Co Ltd
Priority date: 2005-04-08
Filing date: 2005-04-08
Publication date: 2006-10-11
Also published as: GB0507177D0

Abstract

A typical surround sound system will include two speakers situated behind a listener location. This typically requires a long length of cable which is expensive, unsightly and reduces sound quality. Instead, surround speakers 3 are positioned in front of the listener location 8 for outputting directed sound fields. Reflective elements 7 positioned behind the listener location 8 receive the directed sound fields and reflect to the listener location 8. A control unit 6 delays sound output from the front speakers 2 (because of its shorter signal path) to enable it to be synchronised with the sound reflected to the listener. The advantage is a reduction in cable length.

Description

SURROUND SOUND SYSTEM

The present invention relates to a surround sound system, and more particularly to a surround sound system which can utilize shorter signal cables.

Shorter cables are desirable to reduce the effects of cable impedance and to reduce the damage to home decoration.

Recently, more and more consumers have set up "home theater" installations. No matter what the type of "home theater", in each case they require cables extending from front to rear along two sides of the room for electrically connecting to rear surround speakers.

In general, the quadraphonic surround sound system with a basic surround sound effect includes a pair of front speakers and a pair of rear surround speakers. In the 4.1 channel surround sound system, a sub woofer is provided at an arbitrary position in the typical room with respect to the quadraphonic surround sound system. In the 5.1 channel surround sound system, a central speaker is added at a front position in the typical room ideally facing the listener, thereby to produce a better surround sound effect.

In general, a home theater with 5.1 channel sound effect (5.ICH) including a main channel, a central channel, a rear surround channel and a super bass has become standard equipment in the mind of the consumer.

However, although consumers increasingly respect their home decoration this may be damaged by extending the signal cabling to the rear surround speakers of the home theater.

Furthermore, in order to enable amplifiers to drive the speakers, the signal cables and speaker cables must be extended to the amplifiers and the speakers.

However, the lengths of the signal cables and the speaker cables will affect the sound quality. Although wireless speakers have been developed for raising the sound quality wireless speakers are more expensive than conventional speakers using the signal cables and the speaker cables.

In other words, if a home theater with 5.1 channel sound effect (5.ICH) is constructed by means of the wired connections, the home decoration will be damaged by running the signal cables to the rear surround speakers of the home theater. Furthermore, if the home theater is constructed by means of wireless connections, the cost of wireless speakers is too great.

In short, the problems of excessive cost and for extending cables need to be solved in the development of the home theater.

An object of the present invention is to overcome or alleviate the above problems.

The invention is defined in claim 1.

The invention enables a rear sound effect to be obtained without positioning surround speakers behind the listener. Hence, it is not necessary to run the signal cables to the rear of the listener location and shorter cables can be used. 1'his reduces the undesirable effects of cable impedance and prevents damage to the interior decor.

In one embodiment, a surround sound system includes a pair of front speakers, a pair of surround speakers, a pair of reflective elements and a control unit. The front speakers are positioned in front of the listener location.

The surround speakers are positioned in front of the listener location for outputting directed sound fields. The reflective elements are positioned to the rear of the listener location for receiving the directed sound fields of the surround speakers and then reflecting to the listener location. The control unit is electrically connected to the front speakers and the surround speakers, thereby to delay output of forward sound signals of the front speakers.

Such a surround sound system, including at least one control unit, a plurality of speakers and a pair of reflective elements, produces a convincing surround sound effect in a typical room.

To provide a further understanding of the invention, the following detailed description illustrates embodiments and examples of the invention, this detailed description being provided only for illustration of the invention, with reference to the drawing, wherein: FIG. I is a schematic diagram illustrating a surround sound system of the present invention.

With reference to FIG. 1, the surround sound system of the preferred embodiment includes a pair of front speakers 2, a pair of surround speakers 3, a central speaker 4, a super bass speaker 5, at least one control unit 6 and a pair of reflective element 7. The front speakers 2 are positioned at the left and right sides in front of the listener location 8, respectively. The central speaker 4 is positioned in front of the listener location 8, ideally facing the listener. The super bass speaker 5 is positioned at an arbitrary position in front of the listener location 8. The surround speakers 3 are not positioned behind the listener location 8, but at the left and right sides in front of listener location 8.

The surround speakers 3 are directed speakers for outputting directed sound fields and then reflecting to the listener location 8. The control unit 6 is electrically connected to the front speakers 2, the surround speakers 3, the central speaker 4 and the bass speaker 5, thereby to transmit audio signals to the above speakers for outputting sound.

Accordingly, in the above surround sound system, the surround speakers 3 are positioned in front of the listener location 8, and their sound fields are directed to the reflective elements 7 behind the listener location 8.

Hence the listener doesn't directly hear the directed sound fields outputted from the surround speakers 3. Furthermore, the directed sound fields are received and then reflected back from behind the listener. In other words, although the surround speakers 3 are positioned in front of the listener location 8, rear sound effects can still be achieved by reflection of the directed sound

fields from the reflective element 7.

However, after reflecting the sound fields, they will be delayed. Thus, forward sound signals must be delayed to synchronise them with the delayed rear sound signals. Therefore, the control unit 6 is provided for enabling the forward sound signals of the front speakers 2, the central speaker 4 and the bass speaker 5 to be delayed to compensate for the increased length of the sound path (approximately d) introduced by the reflective elements 7, so that the sound outputs of the surround speakers 3 can be synchronous with those of the other speakers and satisfy the requirement of the 5.1 channel surround sound system.

The surround speakers 3 are positioned in front of the listener location 8 to eliminate the problem of running signal cables to a rear of the listener location 8.

Furthermore the delay applied by the control unit 6 is set in response to manual input of distance data (i.e. d), or via automatic detection of the distance d from the speaker 3 to the reflective elements 7 and calculation of the corresponding delay time. The control unit 6 can be a controlling box, a computer for outputting the sound signals or applying a delay, or a controlling circuit for installation in one of the front speakers 2, the surround speakers 3 and the central speaker 4. The reflective elements 7 have sonically reflective

surfaces for reflecting the sound fields.

It is believed that this new field of technology will become of greater significance with the evolution of the surround speakers technology.

Furthermore, those skilled in the art will readily appreciate that the above description is only illustrative of specific embodiments and examples of the invention. In a variant, the reflective elements 7 could be dispensed with and the sound from the speakers 3 could be reflected from interior wall surfaces of the listening room.

Claims

CLAIMS: 1. A surround sound system, comprising: a pair of front speakers

positioned in front of a listener location; a pair of surround speakers positioned in front of the listener location for

outputting directed sound fields;

sound reflecting means positioned behind the listener location for receiving the directed sound fields of the surround speakers and then reflecting to the listener location, and a control unit electrically connected to the front speakers and the surround speakers, and arranged to delay the output of forward sound signals.
2. The surround sound system of claim I, wherein the control unit is arranged to delay the output of the forward sound signals of the front speakers.
3. The surround sound system of claim 1 or claim 2, wherein the control unit is arranged to receive manually input distance data and to a delay period.
4. The surround sound system of claim 1, wherein the control unit is arranged to detect distance automatically and to calculate a corresponding delay time.
5. The surround sound system of any preceding claim, wherein the control unit is a controlling box.
6. The surround sound system of any of claims ito 4, wherein the control unit is a computer.
7. The surround sound system of any of claims ito 4, wherein the control unit is a controlling circuit for installation in one or more of the front speakers or surround speakers.
8. The surround sound system of any preceding claim, wherein the sound reflecting means comprises two reflective elements having sonically reflective surfaces disposed for reflecting the sound fields of the surround speakers.
9. The surround sound system of any preceding claim, further comprising a central speaker positioned between the pair of front speakers.
10. The surround sound system of any preceding claim, further comprising a bass speaker positioned in front of the listener location.
11. A surround sound system substantially as described hereinabove with reference to the accompanying drawing, Figure 1.