This application claims the benefit, under 35 U.S.C. §365 of International Application PCT/USO4/30949, filed Sept. 22, 2004, which was published in accordance with PCT Article 21(2) on Apr. 7, 2005 in English. and which claims the benefit of U.S. provisional patent application No. 60/505,502, filed Sept. 24, 2003. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an apparatus and method for transmitting audio information and, in particular, to an apparatus and method for wirelessly transmitting audio data to one or more speakers in a home theater system. 
     2. Background Information 
       FIG. 1  depicts a block diagram of a conventional or traditional prior art home theater or surround sound system generally designated  10 . The conventional home theater or surround sound system  10  includes a home theater receiver  12  as its main component. Physically connected by wire to the receiver  12  are a right speaker  14 , a left speaker  16  and a center speaker  18 . The receiver  12  is operable to provide right channel audio signals to the right speaker  14 , left channel audio signals to the left speaker  16 , and center channel audio signals to the center speaker  18 . 
     Also physically connected by wire to the receiver  12  are a right surround speaker  20 , a left surround speaker  22 , and a subwoofer  24 . The receiver  12  is operable to provide right surround audio signals to the right surround speaker  20 , left surround audio signals to the left surround speaker  22 , and subwoofer signals to the subwoofer  24 . Because all of the speakers need to be physically connected to the receiver  12 , it is apparent that such home theater or surround sound systems present many challenges to the easy and/or efficient installation thereof. As such, many consumers may forego purchase of a home theater system because of installation obstacles. 
     Many consumers who desire home theater systems such as the system depicted in  FIG. 1  encounter difficulty in wiring the surround speakers since the surround sound speakers are placed at some distance from the receiver. Such difficulty may be due to several reasons but is typically because of aesthetic concerns or logistical problems. Because of this, many consumers reluctantly forgo connecting their surround speakers, resulting in less than optimal home theater sound performance as well as consumer frustration. 
     In view of the above, various wireless surround sound solutions have been developed. Most wireless surround solutions utilize an “analog audio over RF” solution which, while easy and cost effective to achieve, results in poor audio quality. Since the purpose of a home theater or surround sound system is to have superior sound, such poor audio quality defeats the purpose of such a purchase. This leads to the premise of utilizing digital technologies rather than analog technologies. However, if digital technologies are used, solutions become quite expensive to implement. Moreover, unless the wireless surround sound speakers are driven by battery, wires are still needed from the home theater receiver to the surround sound speakers in order to power the surround sound speakers. The use of battery driven surround sound speakers is not an acceptable solution for obvious reasons. 
     For example, if the surround sound speakers include a wireless receiver and amplifier for the wireless signals, the surround sound speakers still need a power source to drive the receiver and amplifier. Alternatively, if the surround sound speakers do not include a wireless receiver and amplifier, the surround sound speakers need to connect to an external receiver/amplifier which, again, still needs a separate power supply. 
     Thus, even though such prior art wireless system are somewhat better than the traditional home theater systems, the prior art wireless systems are nonetheless still present installation obstacles. 
     It is thus evident from the above discussion that what is needed is a surround sound speaker solution that alleviates installation obstacles. 
     It is thus further evident from the above discussion that what is needed is wireless surround sound speaker solution that alleviates the shortcomings of the prior art. 
     It is thus also evident from the above that what is needed is a wireless surround sound speaker solution that provides digital sound quality. 
     These needs and others are accomplished through application of the principles of the subject invention and/or as embodied in one or more various forms and/or structures such as are shown and/or described herein. 
     SUMMARY OF THE INVENTION 
     In accordance with the principles of the subject invention, a subwoofer is equipped with a wireless receiver to receive signals containing information for a Low Frequency Effects (LFE) channel and information for both surround channels. The subwoofer utilizes the LFE channel information, powers surround speakers, and passes the surround channel information signals to respective surround speakers. In this manner, the subwoofer may be positioned at a remote location relative to a surround sound system receiver, such as at the rear of the room having the surround sound system. This way, no separate power wires are needed for the surround speakers while the surround speakers are remote from and not coupled to the surround sound system receiver. 
     According to one embodiment, LFE channel signals are digitally multiplexed into either one or both surround channels when transmitted to the subwoofer. The subwoofer demultiplexes the received signals to separate the LFE channel signals from the surround channels signals. In one implementation or form of the present invention, the multiplexed signals are converted to Red Book CD format using eight to fourteen modulation (EFM) before the signals are transmitted to the subwoofer. 
     In addition to the LFE channel signals being multiplexed into either one or both surround channels, bass frequency audio components may be also multiplexed into either one or both surround channels. 
     According to another embodiment, LFE channel signals are added to either one or both surround channels initially in analog format by the surround sound system receiver. The signals are summed and converted to pulse code modulation (PCM) format. The PCM format signals are then encoded into Red Book CD format using EFM and transmitted to the subwoofer over an RF (Radio Frequency) carrier. An RF receiver located inside or near the subwoofer then demodulates the RF EFM signals, and converts the PCM signals to analog audio. 
     The LFE channel can be extracted from one or both surround channels using a simple low pass filter and amplified by the subwoofer. If the LFE is extracted from both channels, the two LFE signals should be recombined using a summing amplifier. The resulting audio signal is then amplified by the subwoofer. 
     In one form, the subject invention provides a wireless subwoofer for use in a surround sound system. The wireless subwoofer includes a receiver for wirelessly receiving a signal including both subwoofer and surround components, and an extractor for extracting the subwoofer component from the received signal to drive the subwoofer. The subwoofer also provides appropriate right and left surround components to right and left surround speakers respectively to drive the surround speakers. 
     In another form, the subject invention provides a surround sound receiver. The surround sound receiver includes a first port for connecting to a first front speaker, a second port for connecting to a second front speaker, a combiner for combining signals from subwoofer and surround channels, and a transmitter for wirelessly transmitting the combined signal to a subwoofer. The subwoofer wirelessly receives the combined signal, extracts the subwoofer channel from the combined signal, powers surround speakers, and provides a signal including the surround channels to the surround speakers. The surround sound receiver preferably, but not necessarily, also includes a third port for connecting to a center speaker. 
     In still another form, the subject invention provides a method of driving a surround sound subsystem having a subwoofer and surround sound speakers. The method comprises the steps of: (a) combining, at a surround sound receiver, a subwoofer signal with and a surround signal; (b) wirelessly transmitting the combined signal via a digital RF transmitter associated with the surround sound receiver; (c) receiving the wirelessly transmitted combined signal with a wireless digital RF receiver associated with the subwoofer; (d) extracting the subwoofer signal from the combined signal to drive the subwoofer with the extracted subwoofer signal; and (e) providing the surround signal to the surround sound speakers connected to the subwoofer to drive the surround sound speakers with the surround signal. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above mentioned and other features and objects of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of one embodiment of the invention taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a block diagram of a conventional prior art configuration of a home theater or surround sound system; 
         FIG. 2  is a block diagram of an exemplary home theater or surround sound system in accordance with the principles of the present invention; 
         FIG. 3  is a block diagram of an embodiment of the home theater or surround sound system of  FIG. 2  in accordance with the present principles; 
         FIG. 4  is a block diagram of another embodiment of the home theater or surround sound system of  FIG. 2  in accordance with the present principles; 
         FIG. 5  is a block diagram of a further embodiment of the home theater or surround sound system of  FIG. 2  in accordance with the present principles; and 
         FIG. 6  is a flowchart of an exemplary manner of overall operation of the present invention. 
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views. Although the drawings represent embodiments of the invention, the drawings are not necessarily to scale and certain features may be exaggerated in order to better illustrate and explain the present invention. The exemplification set out herein illustrates one embodiment of the invention, in one form, and such exemplification is not to be construed as limiting the scope of the invention in any manner. 
     DETAILED DESCRIPTION 
     The embodiment disclosed herein is not intended to be exhaustive or limit the invention to the precise form disclosed so that others skilled in the art may utilize its teaching. 
       FIG. 2  depicts a block diagram of a home theater system generally designated  30  embodying the principles of the present invention. The home theater system  30  has a first subsystem or portion generally designated  32  that may be termed a main subsystem or portion. The main subsystem  32  includes a home theater receiver  36  that, in addition to the function and/or operation as described herein in accordance with the present principles, functions in a manner such as is known in the art for a home theater receiver including the receipt, processing and/or distribution (collectively, processing) of audio or audio/video signals from one or more sources or inputs to one or more destinations or components. As an audio processor, the receiver  36  provides audio signals for production of audio through appropriate audio reproduction devices (e.g. speakers). 
     As such, the main subsystem  32  includes a right audio speaker (speaker)  38 , a left audio speaker (speaker)  40  and a center audio speaker (speaker)  42 . The receiver  36  includes a right channel audio output or speaker port  37  from which a right channel audio signal or signals are provided to the right speaker  38  via a wire connection as represented in  FIG. 2  by the line extending between the port  37  and the speaker  38 . The receiver  36  also includes a left audio channel output or speaker port  39  from which a left channel audio signal or signals are provided to the left speaker  40  via a wire connection as represented in  FIG. 2  by the line extending between the port  39  and the speaker  40 . The receiver  36  further includes a center channel audio output or speaker port  41  from which a center channel audio signal or signals are provided to the center speaker  42  via a wire connection represented in  FIG. 2  by the line extending between the port  41  and the speaker  42 . The main system  32  also includes a digital RF transmitter system  50  whose function, operation and/or features are described below. It should be understood, however, that while the digital RF transmitter  50  is shown as part of or incorporated into the receiver  36 , the digital RF transmitter  50  may be external to or separate from the receiver  36 . 
     The home theater system  32  also includes a second subsystem or portion generally designated  34  that may be termed a surround sound, surround or enhanced subwoofer subsystem or portion. The surround subsystem  34  includes a subwoofer  44 , a right surround sound (surround) speaker  46  and a left surround sound (surround) speaker  48 . The subwoofer includes a right surround sound (surround) channel port  45  from which a right surround sound (surround) channel audio signal or signals are provided to the right surround speaker  46  via a wire connection represented in  FIG. 2  by the line extending between the port  45  and the speaker  46 . The right and left surround speakers may also be termed right and left rear speakers. The subwoofer also includes a left surround sound (surround) channel port  47  from which a left surround sound (surround) channel audio signal or signals are provided to the left surround speaker  48  via a wire connection represented in  FIG. 2  by the line extending between the port  47  and the speaker  48 . The subwoofer system  34  also includes a digital RF receiver system  52  whose operation, function and/or features are described below. It should be understood, however, that while the digital RF receiver  52  is shown as part of or incorporated into the subwoofer  44 , the digital RF receiver  52  may be external to or separate from the subwoofer  44 . 
     The home theater system  30  shown in  FIG. 2  is known as a 5.1 system, in that there are five (5) speakers (a right and left speaker, a center speaker, and right and left surround sound speakers) and a single (1) subwoofer. It should be appreciated, however, that the present invention is applicable to other speaker system configurations such as 7.1 systems (seven speakers and a single subwoofer). 
     The main subsystem  32  further includes the digital radio frequency (RF) transmitter  50  that is associated with or is part of the receiver  36 . The digital RF transmitter  50  is operable, configured and/or adapted to provide modulation of audio using CD format such as that to comply with the standard Red Book CD format prior to transmission. The process for converting the audio data to the Red Book CD format are well known by those skilled in the art, and may be accomplished by utilizing an SAA 7392 IC manufactured by Philips Corporation. The audio data is first converted to PCM format, wherein the signal is time sampled and amplitude quantized into a parallel binary number. This is typically accomplished in an analog to digital converter (ADC). The digital data is then processed to provide Cross-Interleaved Reed Solomon Coding (CIRC) error correction encoding and eight to fourteen modulation (EFM). 
     The data according to the Red Book CD format is grouped into frames, wherein each frame consists of 588 channel bits. Each frame consists of a 27 bit synchronization portion, an 8 bit SUBCODE portion (if applicable or necessary), a 96 bit data portion, a 32 bit parity portion, a second 96 bit data portion, and a second 32 bit parity portion. In assembling a frame, six 32 bit PCM audio sampling periods are grouped in a frame and each sampling frame is then divided to produce four 8 bit audio symbols. To scatter possible errors, the symbols from different frames are interleaved so that the audio signals from one frame originate from different frames. In addition, eight 8 bit parity symbols are generated for each frame, four in the middle of the frame and four at the end of the frame. The interleaving of the frames and the generation of the parity frames provides the error correction encoding based on the Cross-Interleave Reed Solomon Code. Once the frames have been assembled, the data is EFM encoded, wherein blocks of 8 bits are translated to blocks of 14 bit words using a table that assigns a particular 14 bit word to each 8 bit word. In one embodiment, the assembly of the frame, including the interleaving of the data and the EFM encoding is performed by a CD format encoder which comprises a CIRC encoder, control and display encoder, time multiplexer and EFM modulator all within the digital RF transmitter  50 . It should be appreciated, however, that the above functions and processes may be implemented with other various components and software elements known to those skilled in the art. The conversion results in an EFM signal, which is then conditioned to produce the modulating signal. 
     Moreover, the digital RF transmitter  50  may be operational as follows. The EFM signal is frequency band limited to sinusoidal fundamentals by signal conditioning within the digital RF transmitter  50  in order to simplify the subsequent frequency modulation stage whereby the analog-like signal will frequency modulate a carrier to transmit the audio to the digital RF receiver  52 . The EFM signal may be band limited such as between 180 kHz to 720 kHz. The conditioned EFM signal is used to modulate an RF carrier signal by the digital RF transmitter  50  which includes a radiator or antenna. 
     This scheme, however, supports stereo only. Thus, the CD format may only support two channels. In the present case, these two channels are the right surround sound audio channel and the left surround sound audio channel. In accordance with the principles of the subject invention, however, the receiver  36  through and/or via the digital RF transmitter  50 , multiplexes LFE (Low Frequency Effects) channel of the surround sound system, also known as the subwoofer channel, into either one or both of the right and left surround channels. The combined audio, subwoofer system or enhanced surround sound signal or signals is provided in CD format by the digital RF transmitter  50  of the receiver  36  as described above and wirelessly transmitted to the digital RF receiver  52  of the subwoofer  44 . The subwoofer  44  is operable, configured and/or adapted to receive and process the combined audio signal in order to recover the right surround sound audio channel component from the combined signal, the left surround sound audio channel component from the combined signal, and the subwoofer audio channel (LFE) component from the combined signal. The recovered right surround sound audio channel is provided to the right surround speaker  46 , the recovered left surround sound audio channel is provided to the left surround speaker  48 , and the subwoofer (LFE) channel is provided to the subwoofer  44 . Since the subwoofer  44  is typically provided at the rear of a home theater or surround sound system, a user would have no problem in wiring the surround speakers  46  and  48 . 
     Referring to  FIG. 3 , another exemplary embodiment of a home theater or surround sound system, generally designated  60  embodying the principles of the present invention, particularly those set forth above with respect to the embodiment of  FIG. 2 . As such, the home theater system  60  has a first subsystem or portion generally designated  62  that may be termed a main subsystem or portion, and a second subsystem or portion generally designated  64  that may be termed a surround sound, surround or enhanced subwoofer subsystem or portion. Each of the subsystems  62  and  64  function in accordance with the principles set forth above. 
     The main subsystem  62  includes a home theater receiver  66  having a processor  68  such as or including a digital sound processor. The processor  68  is in communication with a digital RF transmitter  70 . The digital RF transmitter  70  functions in the manner set forth above with respect to the digital RF transmitter  50 . The processor  68  provides the necessary processing and/or control of the receiver  66 . The right, left and center speakers that would be connected to the receiver  66  are not depicted in  FIG. 3  for simplicity. The digital RF transmitter  70  provides the combined surround/subwoofer signal(s) wirelessly as represented by the curved lines emanating from the digital RF transmitter  70  to the subsystem  64 . 
     The surround subsystem  64  includes a subwoofer  72  having a right surround port  73  and a left surround port  75 . A right surround speaker  74  is depicted as connected to the right surround port  73  via a wire represented by a line between the two, while a left surround speaker  76  is depicted as connected to the left surround port  75  via a wire represented by the line between the two. The subwoofer  72  is connected to a power supply or source  78  which provides power to the subwoofer which in turn provides power for/to the surround speakers  74 ,  76 . The subwoofer  72  further includes a digital RF receiver  80 , a processor  82  and an amplifier  84 . 
     Particularly, the digital RF transmitter  70  that is associated with or is part of the receiver  66  is operable, configured and/or adapted to provide modulation of audio using CD format such as that to comply with the standard Red Book CD format prior to transmission. The process for converting the audio data to the Red Book CD format are well known by those skilled in the art, and may be accomplished by utilizing an SM 7392 IC manufactured by Philips Corporation. The audio data is first converted to PCM format, wherein the signal is time sampled and amplitude quantized into a parallel binary number. This is typically accomplished in an analog to digital converter (ADC). The digital data is then processed to provide CIRC error correction encoding and eight to fourteen modulation (EFM). 
     The receiver  66  through the processor  68  and via the digital RF transmitter  70 , multiplexes LFE (Low Frequency Effects) channel of the surround sound system, also known as the subwoofer channel, into either one or both of the right and left surround channels. The combined audio, subwoofer system or enhanced surround sound signal or signals is provided in CD format by the digital RF transmitter  70  of the receiver  66  as described above and wirelessly transmitted to a digital RF receiver  80  of the subwoofer  72 . 
     The subwoofer  72  is operable, configured and/or adapted to receive and process the combined audio signal via the digital RF receiver  80 . The processor  82  is operable, configured and/or adapted via circuitry/logic and/or firmware to recover the right surround sound audio channel component from the combined signal, the left surround sound audio channel component from the combined signal, and the subwoofer audio channel (LFE) component from the combined signal. The recovered right surround sound audio channel is amplified by the amplifier  84  and provided to the right surround speaker  46 . The recovered left surround sound audio channel is amplified by the amplifier  84  and provided to the left surround speaker  48 . The subwoofer (LFE) channel may or may not be amplified by the amplifier  84  and provided to a voice coil (not shown) in the subwoofer  72  producing low frequency sounds. 
     With reference now to  FIG. 4 , there is depicted another embodiment of a home theater or surround sound system, generally designated  90  in accordance with the principles of the subject invention. The system  90  of  FIG. 4  provides a look into a system that is typical of home theater systems in which the present invention or principles thereof may be implemented as well as providing one manner or method of accomplishing multiplexing of the LFE into the surround channels. The system  90  includes a main subsystem  92  and a surround/subwoofer subsystem  94 . The main subsystem  92  includes a surround receiver  96  as a main component while the surround/subwoofer subsystem  94  includes a subwoofer  106 , digital RF receiver  114  and LFE extractor  116  as its main components. Again, no speakers are shown coupled to the receiver  96  for simplicity. A right surround speaker  108  and a left surround speaker  110  are connected to the digital RF receiver  114  to receive the appropriate surround channels after processing by the digital RF receiver  114 . Additionally, the receiver  96  is connected to an appropriate power source or supply  98 , while the digital RF receiver  114  is connected to an appropriate power source supply  112  which provides power as necessary. Typically, this is 120 volt AC such as is standard in U.S. homes. The power supplies  98  and  112  are usually the same source, but accessed via different electrical plugs within the house. 
     Most home theater receivers, like receiver  96  includes a digital sound processor  100 . Additionally, firmware  102  is provided to allow the digital audio processor to function or operate in the manner set forth herein. The digital sound processor  100 /firmware  102  allow configuration for bass management and/or bass redirection. This allows for LFE to be added to all or some of the other five speakers (in a 5:1 system). This also allows for the lower frequency components of the audio channels to be redirected from the speakers to the subwoofer. As such, and in accordance with the principles of the present invention, the digital audio processor  100  is utilized to digitally multiplex the LFE channel onto left and right surround PCM channels. The firmware  102  is modified to allow the LFE channel to be multiplexed onto the left and/or right surround channels, rather than or in addition to the typical case where the LFE is multiplexed into the right and left channels. Additionally, since it is possible to have the bass component of audio redirected from the five speakers to the subwoofer, it is also possible to have the sound processor  100  then multiplex this bass plus LFE signal with the surround channels. Digital multiplexing may be accomplished via several options such as adding LFE to one or both surround channels, or add LFE plus bass frequency audio components to one or both surround channels. Thus, the system  90  provides digital domain processing for creating, providing and receiving the combined LFE/surround signal. 
     The digital RF receiver  114  is operative, configured and/or adapted to receive the wirelessly transmitted surround/subwoofer (combined) signal from the digital RF transmitter  104 . The digital RF receiver  114  processes the received combined signal to retrieve the right surround channel and the left surround channel. The right surround channel is provided to the right surround speaker  108 , while the left surround channel is provided to the left surround speaker  110 . 
     The digital RF receiver  114  also provides the signal to the LFE extractor  116 . The LFE extractor  116  extracts the LFE channel from one or both surround channels for use by the subwoofer. The LFE extractor  116  may include a low pass filter  118  for this purpose. The resulting extracted subwoofer channel is provided to the subwoofer  106 . 
     Referring to  FIG. 5 , there is depicted another exemplary embodiment of a home theater/surround sound system generally designated  130  particularly for the purpose of providing another manner of combining the LFE audio component/signal with one or both surround audio component(s)/signal(s). The system  130  includes a main subsystem  132  and a subwoofer/surround subsystem  134 . The main subsystem  132  includes a receiver  136  having a digital RF transmitter  144  in the same or similar manner to those described above. No speakers are shown connected to the receiver  136  nor are power shown for simplicity. The subwoofer/surround subsystem  134  includes a subwoofer  146 , a right surround speaker  148  and a left surround speaker  150 . Power  152  is provided to the subwoofer  146 . 
     In the system  130 , the LFE is summed in the analog domain with one or both the right and left surround channels, then encode the resulting stereo channels digitally for digital transmission by the digital RF transmitter  144 . Particularly, the LFE, the right surround channel and/or the left surround channel are summed in a summer  138 . Thereafter, the summed signal is provided to a PCM  140 . The resulting stereo digital PCM signal is then encoded using an EFM modulator  142 , then transmitted over an RF carrier by the transmitter  144 , the wireless signal represented by the curved lines. 
     An RF receiver  154  in or associated with the subwoofer  146  receives the combined signal. An EFM demodulator  156  then demodulates the RF EFM signal. A PCM to analog processor/processing circuitry  158  then converts the stereo PCM signal to analog audio. The analog audio signal contains the LFE channel in one or both of the surround channels. The PCM to analog processor/processing circuitry  158  provides the surround channels to an amplifier  162  which, in turn, provides the right surround channel to the right surround speaker  148  and the left surround channel to the left surround speaker  150 . The PCM to analog processor/processing  158  further provides the signal to the LFE extractor/extraction circuitry  160  which extracts the LFE channel from one or both stereo surround channels such as via a low pass filter. Thereafter, the LFE signal is amplified by the amplifier  162  for use by the subwoofer. If the LFE is extracted from both surround channels, the two LFE signals should then be recombined using a summing amplifier, and then amplified by the subwoofer. 
     Alternatively, the LFE component may also be removed from the surround channels using simple high pass filters. In some cases (if LFE signal would damage surround speakers), it may be advantageous to remove the LFE component. In other cases (where surround speakers can handle the LFE component, or where surround speakers filter out the LFE component), it may not be necessary to high pass filter the LFE component. 
     Referring to  FIG. 6 , there is depicted a flowchart, generally designated  170 , depicting an exemplary manner of operation of the present invention. In step  172 , the subwoofer (e.g. LFE) signal/channel is combined with one or both surround signals/channels. This is accomplished in various manners as described above within the receiver. In step  174 , the combined signal is then wirelessly transmitted via a digital RF transmitter associated with the receiver. In step  176 , the combined signal is wirelessly received by a digital RF receiver associated with the subwoofer. In step  178 , the subwoofer extracts the subwoofer signal/channel from the combined signal to drive the subwoofer with the extracted subwoofer signal/channel. The extraction depends on how the signals/channels were combined. Lastly, in step  180 , the surround signal(s)/channel(s) is provided to one or both (i.e. right and/or left) surround speaker that is or are connected to the subwoofer. 
     It should be appreciated that the flowchart  170  described above and depicted in  FIG. 6  provides a manner of exemplary operation of the subject invention as described herein. The subject invention may be implemented utilizing less or different steps than all of the steps of the flowchart  170 . This may be reflected in the claims. Moreover, more or less steps in alternative embodiments of the procedure, method or operation  170  may implement the subject invention in accordance with the principles recited herein. As well, subsets of the above procedure  150  may implement the principles of the subject invention rather than the entire procedure. Variations are also contemplated. 
     While this invention has been described as having a preferred design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, of adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and that fall within the limits of the appended claims.
A subwoofer is equipped with a wireless receiver to receive signals containing information for a Low Frequency Effects (LFE) channel and information for both surround channels. In one form, the LFE is added to one or both surround channels to provide a stereo surround signal (containing both surround channels) including a multiplexed LFE channel. The subwoofer utilizes the LFE channel, powers surround speakers, and passes the surround signals to respective surround speakers. A receiver multiplexes LFE signals into either one or both surround sound audio channels. A digital RF transmitter of the receiver transmits the combined subwoofer/surround channels to the wireless receiver of the subwoofer. The remote subwoofer is connected to a power source. The surround speakers are connected to the subwoofer so as to receive the surround channels and be powered thereby.