[0001] This application claims the benefit of People's Republic of China application Serial
No. 200510008143.8, filed February 5, 2005, the subject matter of which is incorporated
herein by reference.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] The invention relates in general to a wireless audio system, and more particularly
to a wireless low-frequency audio system for an electronic device.
Description of the Related Art
[0003] A conventional television set produces a source audio signal and typically includes
two speakers for reproducing left and right channels of stereophonic sound according
to the source audio signal. Unfortunately, these built-in speakers have worse performance
in reproducing low frequencies, such as bass sound. In order to prevent the two speakers
from making noise due to weakness in reproducing low frequencies, an audio processing
device in the television set conventionally filters out low frequency components of
the source audio signal produced by the television set.
[0004] Hence, with such a design limitation, the television set could not reproduce low
frequencies through its built-in speakers even if it displays a video or television
program with full-range sound effects. In particular, users cannot experience woofer
or subwoofer sounds when watching a movie with subwoofer sounds, sounds of engines
for example. Therefore, the users who would like to enjoy that woofer or subwoofer
sound effects have to additionally purchase an audio system as well as a number of
audio cables for connection between the audio system and additional speakers to reproduce
the effects. Such approach to the enjoyment of sound effects is complex and the system
together with the cables and speakers occupies users' space, not only spending much
more money but also making inconvenience in installation and use.
SUMMARY OF THE INVENTION
[0005] An object of the invention is to provide a wireless low-frequency audio system for
an electronic device in order to solve the deficiency of a conventional television
set, which cannot reproduce the bass sound effects. The wireless low-frequency audio
system transmits a low-frequency portion of a source audio signal produced by the
electronic device to a low-frequency speaker wirelessly, thus providing flexibility
in locating the low-frequency speaker.
[0006] According to an embodiment of the invention, a wireless low-frequency audio system
for an electronic device is provided. The electronic device is an audio-video reproduction
system including an audio-video reproduction device and an audio reproduction device.
The wireless low-frequency audio system reproduces sound in response to a source audio
signal of the audio-video reproduction system. The wireless low-frequency audio system
includes an audio processing device, a wireless transmission module, and the audio
reproduction device. The audio processing device and wireless transmission module
are disposed in the audio-video reproduction device. The audio reproduction device
includes a low-frequency speaker, a wireless receiving module, and an amplifier.
[0007] The audio processing device is for producing a signal representing a low-frequency
portion of the source audio signal according to the source audio signal. The wireless
transmission module wirelessly transmits a wireless signal according to the signal
representing the low-frequency portion of the source audio signal. The wireless receiving
module is for wirelessly receiving the wireless signal and producing a low-frequency
audio signal according to the wireless signal. The amplifier is used for driving the
low-frequency speaker to reproduce sound according to the low-frequency audio signal
from the wireless receiving module.
[0008] Other objects, features, and advantages of the invention will become apparent from
the following detailed description of the preferred but. non-limiting embodiments.
The following description is made with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 illustrates an electronic device according to a preferred embodiment of the
invention.
[0010] FIG. 2 is a block diagram illustrating the wireless low-frequency audio system for
the electronic device illustrated in FIG. 1 according to the preferred embodiment
of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0011] In accordance with the invention, a wireless low-frequency audio system for an electronic
device wirelessly transmits a low frequency portion of a source audio signal of the
electronic device, i.e. low-frequency audio components, all or in part, of the source
audio signal, to a low-frequency speaker. In this way, locating of the low-frequency
speaker becomes more flexible, without the inconvenience of using connecting audio
cables, as the conventional approach requires.
[0012] FIG. 1 illustrates an electronic device according to a preferred embodiment of the
invention. The electronic device 100 is an audio-video reproduction system, for example.
The audio-video reproduction system 100 includes an audio-video reproduction device
104 and an audio reproduction device 108. The audio-video reproduction device 104
is a device or system that can display video and audio. The audio-video reproduction
device 104 shown in FIG. 1 is a television set according to this embodiment, wherein
the television set can be a liquid crystal display television set, a plasma television
set, or a cathode ray tube television set. In another embodiment, the audio-video
reproduction device 104 can be a computer system, such as a desktop computer, a notebook
computer, or a barebone computer system. The audio reproduction device 108 wirelessly
links to the audio-video reproduction device 104 and wireless signals are transmitted
between them.
[0013] Referring to FIG. 2, a wireless low-frequency audio system for the audio-video reproduction
system 100 is shown in block diagram form. The wireless low-frequency audio system
200 includes an audio processing device 204, a wireless transmission module 206, and
the audio reproduction device 108. The audio processing device 204 and the wireless
transmission module 206 are disposed in the audio-video reproduction device 104. The
audio reproduction device 108 includes a low-frequency speaker SP, a wireless receiving
module 210, and an amplifier 212.
[0014] In this embodiment, the audio-video reproduction device 104 is a television set which
displays a video according to a media signal VS representing video and audio of, for
example, a broadcasting television program or a movie from a digital video disk or
video compact disk. In response to the media signal VS, the audio processing device
204 of the audio-video reproduction device 104 outputs a low-frequency audio signal
SS, and audio signals for multi-channel stereophonic sound according to a source audio
signal obtained from the media signal VS, for example, a left-channel audio signal
L and a right-channel audio signal R. The audio signal L and R represent frequency
components greater than about a specific frequency, e.g. 180Hz, of the left and the
right channels of stereophonic sound, respectively, according to the source audio
signal. In addition to the audio signals L and R, the audio processing device 204
outputs the low-frequency audio signal SS, representing low frequency components less
than about a specific frequency, e.g. 180 Hz, according to the source audio signal.
The audio processing device 204 utilizes, for example, a high-pass filter and a low-pass
filter, or an equalizer, to separate the audio frequency components from the source
audio signal into the left- and right-channel audio signals L and R and the low-frequency
audio signal SS. The left and right speakers of the television set, as illustrated
by the speakers 114 and 116 in FIG. 1, produce sound corresponding to the left- and
right-channel audio signals L and R. By contrast, the audio processing device 204
outputs the low-frequency audio signal SS to the wireless transmission module 206.
[0015] The wireless transmission module 206 converts the low-frequency audio signal SS into
a wireless signal SS' according to the information of the low-frequency audio signal
SS, and wirelessly transmits the wireless signal SS' to the audio reproduction device
108. The wireless receiving module 210 of the audio reproduction device 108 wirelessly
receives the wireless signal SS' and produces a low-frequency audio signal SS" according
to the wireless signal SS' received. In one embodiment, the wireless receiving module
210 converts the received wireless signal SS' into the low-frequency audio signal
SS" in an analog form through digital-to-analog conversion. The low-frequency audio
signal SS" is then fed into the amplifier 212. In response to the low-frequency audio
signal SS", the amplifier 212 amplifies the signal SS" and drives a low-frequency
speaker SP, for example, a woofer or subwoofer, to produce sound according to the
low-frequency audio signal SS". The wireless transmission module 206 and wireless
receiving module 210 are compliant with Bluetooth wireless specification, for example.
[0016] The above disclosed embodiment of a wireless low-frequency audio system for a television
set can reproduce low-frequency sound, even subwoofer sound, according to a low-frequency
audio signal, without the need of an expensive audio system. In addition, transmitting
a wireless signal representing low-frequency audio to the low-frequency speaker wirelessly
makes locating the audio reproduction device 108 more flexible, depending on the users'
preferences and without location limitation by audio cables' length as in the conventional
approach. In this way, the wireless low-frequency audio system for the electronic
device makes the users' living space with the system neat and tidy, meeting the users'
need for good-looking living environment.
[0017] While the invention has been described by way of examples and in terms of a preferred
embodiment and other embodiments, it is to be understood that the invention is not
limited thereto. On the contrary, it is intended to cover various modifications and
similar arrangements and procedures, and the scope of the appended claims therefore
should be accorded the broadest interpretation so as to encompass all such modifications
and similar arrangements and procedures.
1. A wireless low-frequency audio system for reproducing sound in response to a source
audio signal of an electronic device, the system comprising:
an audio processing device for producing a low-frequency audio signal representing
a low-frequency portion of the source audio signal;
a wireless transmission module for wirelessly transmitting the low-frequency audio
signal; and
an audio reproduction device, comprising:
a low-frequency speaker;
a wireless receiving module for wirelessly receiving the low-frequency audio signal;
and
an amplifier for amplifying the low-frequency audio signal to drive the low-frequency
speaker.
2. The system according to claim 1, wherein the wireless transmission module and the
wireless receiving module are compliant with Bluetooth wireless specification.
3. The system according to claim 1, wherein the electronic device is a television set.
4. The system according to claim 1, wherein the electronic device is a computer system.
5. The system according to claim 4, wherein the computer system is a notebook computer.
6. The system according to claim 4, wherein the computer system is a desktop computer.
7. The system according to claim 4, wherein the electronic device is a barebone computer
system.
8. An audio-video reproduction system, comprising:
an audio processing device, for producing a low-frequency audio signal according to
a source audio signal of the audio-video reproduction system;
a Bluetooth transmission module for wirelessly transmitting the low-frequency audio
signal; and
a low-frequency speaker;
a Bluetooth receiving module for wirelessly receiving the low-frequency audio signal;
and
an amplifier for amplifying the low-frequency audio signal to drive the low-frequency
speaker.
9. The system according to claim 8, wherein the audio-video reproduction system is a
liquid crystal display television system.
10. The system according to claim 8, wherein the audio-video reproduction system is a
plasma display television system.
11. The system according to claim 8, wherein audio-video reproduction system is a cathode
ray tube television system.