Abstract: An audio player capable of allowing multiple persons to listen to different multimedia files simultaneously is provided. The audio player includes a processing unit and a plurality of output channels. Each of the output channels is configured for outputting multimedia files. Each of the output channels includes a codec, an amplifier, and an audio output port. The amplifier is connected to the codec and the audio output port. The processing unit is connected with the output channels. The processing unit is configured for establishing a plurality of processes and for controlling performance of the processes according to time division multiplexing (TDM) technology. Wherein, each of the processes is configured for playing multimedia files and is assigned with one of the output channels for outputting the multimedia files.

Abstract: A communication system has a controller for transmitting data to be played back by a plurality of playback devices corresponding to a plurality of channels, and a plurality of adapters required for executing playback by the playback devices. The controller has a setting unit which sets data to be played back by the playback devices and control information required to control playback of the data in time slots of a sync transmission frame, and a transmission unit which transmits the sync transmission frame the by the setting unit to the adapters. Each adapter has a reception unit which receives the transmitted sync transmission frame, and a playback control unit which extracts data corresponding to the channel to be played back by the adapter from the sync transmission frame, and controls the playback timing of the data based on control information corresponding to the data.

Abstract: An information source management system 11 performs inventory management for CDs and a material information management progress programming system 12 performs programming. An material information registration system 13 compresses the musical numbers of the CDs for holding on a proprietary server and a proprietary server 121 of a multi-channel sending-out system 101. A large number of materials are held on the proprietary server 121 and read out from it. The read-out materials are converted in its format to a transmission format by a sending-out server 123 so as to be multiplexed by a multiplexer 141. The multiplexed data is QPSK-modulated by a modulator 142 and sent out via a selector 143. From the proprietary server 121 are read out data which is sent out via dedicated network 3 to a live PC where it is reproduced. This data is furnished again via dedicated network 3 and encoded by an MPEG encoder 129 so as to be sent out at the sending-out server 123.

Abstract: The invention relates to loudspeaker systems or loudspeaker columns as used in public address systems and at (pop) concerts. Such systems heretofore possess a frequency-dependent coverage angle and strong second and third order side lobes. The invention describes formulae of the voltage to be applied to the separate loudspeakers of the loudspeaker column, which makes it possible to realize the constant coverage angle over the entire frequency range and to suppress the side lobes to a far-reaching extent.

Abstract: Appropriate content is determined from among multiple content items, and is reproduced. Content reproduction terminal devices having the content items recorded therein are connected with a content reproduction controlling apparatus. An acquiring unit acquires content information from each content reproduction terminal device, information indicative of the subject matter of the content items. A determining unit determines the content items to be reproduced, i.e., reproduction content based on the acquired content information. An extracting unit extracts the reproduction content from the content reproduction terminal device that has the reproduction content recorded therein. A reproducing unit reproduces and outputs the extracted reproduction content.

Abstract: A system and method for generating, transmitting and distributing audio signals. The system and method may include an array having a plurality of microphones and a plurality of speakers as well as a first processor disposed proximate the array. The system and method can also have a second processor disposed remotely from the array and communicatively coupled with the array, at least one remotely located device having at least one microphone and at least one speaker and one or more remotely located speakers. Also, there may be an audio signal that is generated by one of a microphone on the array and a microphone on the at least one remotely located device, the location of the generation of the audio signal determined by one of the first processor and the second processor, generated audio signal transmitted to at least one of the speakers on the array, the at least one speaker on the remotely located device and the one or more remotely located speakers.

Abstract: A wireless audio distribution system may include a wireless transmitter transmititing an encoded digital bitstream serially combining each of a plurality of audio input channels and control data, a wireless receiver receiving the transmitted bitstream, a manual selector switch to for selecting one or more of the audio input channels and a sound producing device reproducing the selected audio channels in accordance with the control data. A system may include a wireless receiver receiving an encoded digital bitstream combining each of a plurality of audio input channels with control data disbursed therein, a manual selector switch for selecting audio input channels and a sound producing device for selectively decoding and demultiplexing the selected audio channels to be reproduced in accordance with the control data.

Abstract: A audio codec includes a first analog to digital converter for producing a first one-bit data stream, a second one-bit data stream is received from a digital microphone. A selection module produces a one-bit output signal that is the first one-bit data stream when a selection signal is in a first state, and produces a the one-bit output signal that is the second one-bit data stream when the selection signal is in a second state. A decimation and filter module produces a down sampled signal based on the one-bit output signal.

Abstract: A sound-amplification apparatus comprises: an acoustic signal source for outputting an acoustic signal; an amplified sound source for receiving the acoustic signal from the acoustic signal source and radiating an amplified sound; a control sound source provided in a vicinity of the amplified sound source for radiating a control sound; and signal processing means for producing a control sound signal by controlling at least one of an amplitude and a phase of the acoustic signal from the acoustic signal source so that an acoustic space having a desired directionality is formed by interference between the amplified sound and the control sound, and providing the control sound signal to the control sound source.

Abstract: This invention concerns a distributed stereo audio system (1). Distributed stereo audio systems are used to provide stereo sound to several rooms or areas from a single source of signal. The system includes two or more speakers (2, 3) for the broadcast of stereo audio signals; a source of stereo audio signals; a stereo amplifier (4) to amplify stereo audio signals and drive the speakers; and a mains operated electrical power supply (10) to provide power to the amplifier. The amplifier is located in the same room as the speakers, and remote from the signal source and power supply. The amplifier is connected to the signal source and power supply by means of a category 5 four pair twisted cable (11) which provides, in respective twisted pairs, right channel audio signals (12) from the signal source to the amplifier, left channel audio (13) from the signal source to the amplifier, DC power (14) from the power supply to the amplifier, and control signals (20) from the amplifier to the signal source.

Abstract: The invention concerns a method for transmitting in an area (100) information items in the form of sound waves representing a signal X(t), through a loudspeaker enclosure (2), said method comprising a step of setting up a public address system which consists in applying to the input of the loudspeaker enclosure (2) an electric signal P(t)=W(t) ?X(t) wherein is the convolution product and W(t)=S(?t)? I(t), wherein S(?t) is the temporal return of the pulse response S(t) between the enclosure and the target zone (101) belonging to the area to be fitted with a P.A. system (100) t representing time, and I(t) is the temporal response of the product e?2inft0.Sc (f), wherein f represents the frequency, t0 is a constant Sc(f)=1/(S1(f))?, ? being a non-null positive number and S1(f) being a real function obtained by peak clipping of the modulo I S(f) I of the frequency response S(f) of S(t).

Abstract: Audio source selection circuit (QW) for an audio signal processor with inputs for source signals (F1, F2, NA, NB) provided by at least one source (Q1, Q2), with a processing device (V) which forms pairs of signals from the source signals, with a settable source selection logic (Qs) to which the channels of the processing device (V) are applied, and with outputs coupled to signal outputs of the settable source selection logic (Qs) and each forming an output channel (Co1, Co2, Co3), the processing device (V) including an automatic audio mode setting device which generates suitable intermediate channels (Cz1, Cz2, Cz3, Cz4) from the source signals (F1, F2, NA, NB) according to a source- and application-related mode.

Abstract: An array of speakers are fed from a single source of audio frequency sound but each speaker transmits the sound delayed by an amount which is determined by the distance between a particular speaker and a selected region in space, so that sound from each speaker constructively adds at the selected region in space. A sufficiently large number of speakers are employed so that when sound reaches a region in space at the same moment in time the audio volume will be increased substantially over sound in regions where there is not constructive interference. This simple technique allows audio frequency sound to be heard in only selected regions within the room or other auditory space. Multiple regions with multiple soundtracks can be created by simultaneously playing variously delayed soundtracks over each of the speakers in the array.

Abstract: A sound control system includes a plurality of electronic devices connected to a communication network, each of the electronic devices being capable of independently producing sound from connected speakers, and a sound control device transmitting control signals for controlling the electronic devices and audio signals to the electronic devices via the communication network. Each electronic device includes receiving means for receiving the control signals and the audio signals via the communication network, and selecting means for switching from other external signals to the audio signals in response to the control signals in order to drive the speakers by only the audio signals output to the speakers.

Abstract: A wireless transmission device for communicating a plurality of audio streams to remote devices may include a plurality of inputs for receiving a plurality of digital audio streams, a combiner connected to the inputs for combining control codes and the received audio streams in a predetermined format to form a signal wherein the control codes for controlling the operation of a remote device equipped for processing the signal to extract the audio streams therefrom in accordance with the predetermined format, and a transmitter connected to the combiner to transmit the signal for reception by the remote device. The transmitter may include an infra-red light emitter for transmitting the signal as an infra-red light signal.

Abstract: A time-division method for playing multi-channel voice signals is provided to improve voice qualities of the multi-channel voice signals. The first feature of the present invention is that after time-division sampling, the voice signals can be directly sent to a subsequent voice generator without being demodulated beforehand. The second feature is that the ratio of a specific voice signal to a synthesized voice can be easily adjusted by changing the numbers of channels occupied by the specific voice. Consequently, the adjusting circuitry can be significantly simplified.

Abstract: A wireless audio distribution system having a wireless transmitter, responsive to a plurality of audio input channels, for transmitting a encoded digital bitstream serially combining each of the audio input channel, the encoded digital bitstream further including control data disbursed therein, a receiver, responsive to the transmitted encoded digital bitstream, for decoding and demultiplexing the digital bitstream, a manual selector switch, connected to the receiver device for selecting one or more of the audio input channels to be reproduced, and a sound producing device for selectively reproducing the one or more selected audio channels in accordance with the control data.

Abstract: In a digital audio broadcast system, to utilize transmission bandwidth efficiently, representations of a stereo audio signal for transmission are generated in accordance with an inventive multidescriptive coding technique. The representations, as generated, are then transmitted through multiple communication channels, respectively. The transmitted representations are received by a receiver where one or more of the representations are selected for recovery of the stereo audio signal. Because of the design of the multidescriptive coding used, the more representations are selected to recover the stereo audio signal, the higher the quality of the recovered signal.

Abstract: A method synchronizes signals from unsynchronized sensors spatially dispersed in an environment. Each sensor acquires an unsynchronized signal from the environment. An identical timing signal is received in each sensor. Frequencies of the timing signal are substantially disjoint of frequencies of the unsynchronized signals. The timing signal is combined with the unsynchronized signal in each sensor. The combined signals are received by a signal processor where the combined signals are separated to recover the unsynchronized signals and the timing signals. Then, the unsynchronized signals can be time-aligned according to the recovered timing signals to produce time-aligned signals.

Abstract: An information source management system 11 performs inventory management for CDs and a material information management progress programming system 12 performs programming. An material information registration system 13 compresses the musical numbers of the CDs for holding on a proprietary server and a proprietary server 121 of a multi-channel sending-out system 101. A large number of materials are held on the proprietary server 121 and read out from it. The read-out materials are converted in its format to a transmission format by a sending-out server 123 so as to be multiplexed by a multiplexer 141. The multiplexed data is QPSK-modulated by a modulator 142 and sent out via a selector 143. From the proprietary server 121 are read out data which is sent out via dedicated network 3 to a live PC where it is reproduced. This data is furnished again via dedicated network 3 and encoded by an MPEG encoder 129 so as to be sent out at the sending-out server 123.

Abstract: An audio production, satellite uplink and radio broadcast studio system includes an audio console having a supporting meter bridge and editing unit operative under the control of a central or main computer. The audio console is coupled to a plurality of analog audio information sources including a plurality of microphones, a plurality of telephone lines, a radio broadcast tuner and a plurality of audio tape drives. The audio console is further coupled to a plurality of digital information sources including a pair of ISDN lines, a plurality of compact disc players, a mini-disc player and a remotely operated digital audio recorder. The computer is coupled to the audio console via an interface and sound card. The audio console is coupled to a plurality of program outputs having different program format capabilities and to a distribution amplifier operative to control the various remotely operated recording apparatus within the system.

Abstract: An LCD display has a built-in audio processing device. The audio processing device receives audio signals from a piece of Audio/Video equipment and modulates the received audio signals. The modulated audio signals are further wirelessly emitted by infrared emitting diodes that are mounted in a position near the screen of the LCD display. When a user wears wireless earphones, the audio signals can be received and played by the earphones so people in the proximity of the LCD display will not be distracted by the sound.

Abstract: A method for processing a multichannel audio signal. The method includes mounting electroacoustical transducers in a low frequency augmenting device. The electroacoustical transducers radiate different high frequency acoustic energy and common low frequency acoustic energy. The transducers may be part of directional arrays. The method is applied to multimedia entertainment devices.

Abstract: A first local controller (30) having a device port coupled to a device control port for communicating with a device to be monitored or controlled, a primary local port for coupling to a first interface port (90) of an interface unit, and a secondary local port.

Abstract: A voice interface structure for a cellular phone that permits two-way operation or can be provided at where opposite to the keypad of the cellular phone, wherein, both of the voice interface and control keypad are arranged in two-ways or facing away from each other so that when the keypad control and operation. as well as the use of the voice interface, the case of the cellular phone is used as a screen to reduce the electromagnetic wave the head of the user is exposed to without compromising the convenience of key entering and executing of transmission and receiving.

Abstract: A Wireless Concealed Transmitter Stereo Center Speaker System includes a concealed transmitter unit installed a center speaker, and two receiver units installed in two rear speakers, wherein the concealed transmitter unit includes an automatic audio level regulating circuit to regulate the audio level of the output signal of audio equipment to a predetermined range, a power control circuit controlled by the output signal of the audio equipment to provide the necessary working voltage, and an inductance antenna to transmit stable output signal from the audio equipment to the receiver units of rear speakers; the receiver units are of low working voltage design, including an automatic 24-time frequency divider circuit to effectively discriminate left and right sound tracks, and an auto-shut off circuit to automatically cut off power supply from either an alternating current source or battery power supply when the audio equipment does not work; the concealed transmitter unit and the receiver units further use a r

Abstract: This invention relates to the electronic sound equipment which individually records and reproduces the instruments (sound sources) composing an orchestra or an assemble, and creates delicate and powerful sounds with clearly position of sound. It comprises the record and reproduction section with the same number of the channels as the music sources (including the case of one instrument for several channels), and at least one speaker (non directional speaker system is recommended) for each channel of this record and reproduction section, characterized in by placing the speakers freely on the wall, floor or ceiling, the music scene which is extremely close to a live performance is reproduced at a hall or at home.

Abstract: A storytelling system in which a base unit broaadcasts some blocks of audio data stored therein, and transmits other blocks of audio data stored therein to remote units either for remote broadcast, or cause the remote units to illuminate. Transmission to the remote units may be as radio signals, as ultrasound signals, as infrared signals, or as electrical impulses transmitted along wires. The blocks of data include identification codes to indicate which units are to broadcast the blocks of audio data or illuminate. The remote units have unique identifying features and are covered by matching dolls representing characters of the story. Each remote unit broadcasts the audio data appropriate to its own doll, or illuminates its own doll while the audio data appropriate to its own doll is being broadcast by the base unit.

Abstract: An audio signal processing apparatus including a plurality of jack units each of which has at least an audio signal contact piece and a control signal contact piece. A control circuit judges a kind of an audio appliance connected to each of the plurality of jack units based on a control signal obtained at the control signal contact piece, and when a function change-over command to select any one of the audio appliances is supplied, a function selecting circuit selects one of the jack units to which the audio appliance is connected. An audio appliance can be connected to any of the plurality of jack units.

Abstract: An audio reproduction apparatus includes a primary audio amplifier having an output side for outputting audio signals, and a plurality of auxiliary audio amplifiers coupled electrically in series to the primary audio amplifier. Each of the auxiliary audio amplifiers has an input side for receiving the audio signals from the primary audio amplifier, a signal current generating device coupled electrically across the input side such that the audio signals pass through the signal current generating device, a current inducing device disposed adjacent to the signal current generating device for generating induced audio signals when the audio signals pass through the signal current generating device, an auxiliary amplifier coupled electrically to the current inducing device for amplifying and outputting the induced audio signals generated thereby, and a loudspeaker coupled electrically to the auxiliary amplifier for reproducing the induced audio signals amplified by the auxiliary amplifier.

Abstract: Disclosed is a wireless surround sound speaker system wherein a transmitter broadcasts a variety of FM signals that correspond to the individual speaker channels commonly found in a surround sound system. Receivers, individually equipped with signal receiving, conditioning and amplification components, are configured to receive any one of the broadcast signals in a remote location and are used to drive a conventional loudspeaker in that location. Powered by wall socket or via DC battery packs, the receivers, used in conjunction with the transmitter, provide surround sound capabilities without the need for complex and difficult wiring.

Abstract: Multi channel audio reproduction has already been used for some time. For example the so-called surround sound signals can improve the appearance of reproduced sound to a great extent.

Abstract: A sound processing circuit for distributing low frequency signal components of multichannel audio signals. The sound processing circuit filters low frequency signal components from the digital audio signals of m (m≦n) specified channels using an exclusive channel having low frequency signals and n (n>1) multiple independent channels, and outputs the filtered low frequency signal components as part of a low frequency signal channel.

Abstract: The invention relates to a system and method for controlling an audio spatialisation in real time, comprising:

Abstract: An addressable speaker system in which a plurality of selectively activated speakers are distributed throughout a predefined area and are connected to a central processing unit. The system contains multiple RF antennas that are capable of broadcasting and receiving radio frequency signals to individuals wearing radio frequency identification (RFID) badges. The system users the RF transmission to locate an intended radio frequency identification badge and selectively broadcasts an audio message to a speaker located closest to the intended recipient.

Abstract: Connection of speakers to an electronic apparatus fitted with a plurality of audio signal output terminals independent of the number of audio-signal output channels very easily and discernibly.

Abstract: An automatic LFE audio signal derivation processor incorporating signal measurement functions, signal filtering functions, signal limiting/compressing functions, signal gain adjusting functions, and operating indication functions, for use with multichannel soundtracks. Audio input signals are fed to the processor and split for processing in three blocks, including a detector, which analyzes the low frequency content of the incoming signal and controls each of two subsequent blocks, a variable low frequency shelving network in which the amount of low frequency attenuation is variable and which responds to a control signal from the detector, and a variable gain amplifier in which the gain responds to the control signal from the detector circuit.

Abstract: The present invention makes it possible to readily judge the details of data transmitted through a bus line, such as the channel structure, at the receiver's end. When data is transmitted in a predetermined format per unit having a predetermined data length among devices linked to a certain bus line, the data is transmitted by setting up a section for transmitting auxiliary data of transmission data in a unit having the predetermined data length, and placing identification data related to spatial placement of the transmission data in a first section within the section for transmitting the auxiliary data, and data related to set-up of the transmission data in a second section within the section.

Abstract: The invention relates to a method for implementing a sound reproduction system for a large space, and a sound reproduction system. In accordance with the invention, a) loudspeaker units (LU) are placed in different parts of said space, and the information to be transmitted by the loudspeaker unit to its environment is fed to said loudspeaker unit from an information source (CPU) common to several loudspeaker units, b) determinations specific to said loudspeaker unit are carried out in a separate loudspeaker unit (LU), and c) a message is sent from the loudspeaker unit (LU) to the common information source (CPU), said message (20) containing information obtained on the basis of said determination.

Abstract: A connector device for connecting information-handling apparatus has a common jack connected to a first information-handling apparatus, a plurality of plugs connected respectively to a plurality of second information-handling apparatus having respective different impedances, the plugs being selectively connectable to the jack, and a determining circuit for, when one of the plugs is connected to the common jack, applying a predetermined voltage to a contact of the connected plug through an impedance element, detecting a voltage between the contact of the connected plug and a ground contact thereof, detecting an impedance between the contact of the connected plug and the ground contact thereof depending on the detected voltage, and determining the type of the plug or the type of the second information-handling apparatus connected to the plug depending on the detected impedance.

Abstract: A new audio wireless transmission and reception system for providing spectators at a sporting event audio perspective of the event. The inventive device includes a parabolic dish having a length of wire extending outwardly therefrom. The parabolic dish serves to receive audio signals. A transmitter is connected to the length of wire from the parabolic dish. The transmitter serves to transmit the audio signals received from the parabolic dish. The transmitter is removably positioned within a carrying case. The carrying case is positionable on a back of a technician directing the parabolic dish. A headset radio is adapted for being worn on a head of a wearer. The headset radio is programmed for receiving the audio signals from the parabolic dish via the transmitter.

Abstract: A signal processing system receives and mixes a plurality of analog input signals having a maximum frequency. Each analog input signal is connected to an input of a modulator producing a high frequency oversampled digital signal. Each high frequency oversampled signal is connected to an input of a first decimation filter which produces an intermediate frequency oversampled multiple bit signal. Each of the intermediate frequency oversampled signals is connected to a respective input of a first digital mixer which produces a single mixed multiple bit output signal. The single mixed multiple bit output signal is connected to a second decimation filter which produces a final digital output signal, at a frequency suitable for representing the mixed analog input signals.

Abstract: A recipient-specific voice message playback system detects the presence of a message recipient, identifies the recipient, and plays a message addressed to the recipient. The system includes a recorder. The recorder has multiple channels for recording voice messages. Each channel is assigned to a particular message recipient. A controller couples to the recorder and generates a control signal to regulate message recordation and playback on each channel. A switch also couples to the controller and is associated with each channel. Each switch directs the controller to selectively playback or record a message on each associated channel. The playback system includes a sensor and an alarm. The sensor detects the presence of a recipient and causes the alarm to notify the recipient when a message has been recorded. Actuation of a particular switch identifies a particular recipient and accesses the channel assigned to the particular recipient.

Abstract: A realistic illusion of listening to an actual AM radio is produced by providing a number of audio program signals and by simulating the process of tuning across the radio dial where each station is playing a different program. In a superheterodyne receiver using envelope detection, tuning a station off-channel results in a changing mixture of distortion and noise. The distortion function is caused by a variety of processes, among them being the filtering action as parts of the signal spectrum are cut off by the bandpass filter in the IF amplifier. Another is caused by the reduction in the carrier which causes the foldover of negative peaks in the envelope detector.

Abstract: A data processing device is programmed to decode and transform a stream of data representing a plurality of subband encoded channels of audio data into one or more channels of PCM encoded data for reproduction by a speaker subsystem. An improved method for decoding and transforming utilizes downmix matrices (1021 and 1022) to form downmixed frequency domain channels in buffers (1031-1034). Only two long DCT transform operations (1041 and 1042) and two short DCT transform operations (1043 and 1044) are needed to transform the downmixed frequency domain channels into a left PCM output (1071) and a right PCM output (1072).

Abstract: A system for detecting whether a bus used to connect units in an in-flight entertainment system is properly terminated. A detection circuit generates a bus termination signal when a terminating cap properly terminates the bus. Prior to installation of the terminating cap, a bus coupling contact of the detection circuit is maintained in a logic high or asserted state. A detection loop in the terminating cap grounds or deasserts the bus coupling contact when the terminating cap is properly installed. A microcontroller determines whether the bus coupling contact is grounded and signals a managing unit of the condition. The managing unit may display an appropriate error message to notify service personnel of the improper termination.

Abstract: The single package three channel audio signal amplifier has three amplifier channels which may be used independently to power three output loads or audio speakers or may be paralleled or bridged to increase power to one or two output loads. The integrated circuit is particularly useful for current computers which use audio devices that require signals to be processed by computer circuit boards that have power limitations. The signal amplifier allows switching between one, two and three channel operation. In addition the new device uses class D operation amplifiers which are coupled to the load by ratio transformers to provide increased efficiency and gain. The device has internal limiting and preamplifier control; allows volume adjustment, filter level and range selection, and mute and treble control; and provides on-device voltage regulation.

Abstract: A storytelling system in which a base unit broadcasts some blocks of audio data stored therein, and transmits other blocks of audio data stored therein to remote units for remote broadcast. Transmission to the remote units may be as radio signals, as ultrasound signals, as infrared signals, or as electrical impulses transmitted along wires. The blocks of data include identification codes to indicate which units are to broadcast them. The remote units have unique identifying features and are covered by matching dolls representing characters of the story. Each remote unit broadcasts the audio data appropriate to its own doll.

Abstract: A digital radio broadcast station which includes a common digital database having stored therein a plurality of at least several hundred (preferably at least 1800) different selections of music to be played and broadcast by the radio station. A processor system is provided for programming the operation of the digital radio broadcast station with a sequence of music selections, which are subsequently retrieved in order from the common digital database and played over the digital radio broadcast station. The common digital database comprises a disk array storage, preferably a dual port RAID disk array. The digital radio broadcast station also includes a plurality of work station consoles for use by personnel responsible for operating the radio station such as disc jockeys and engineers. A bridge network such as a modem is also provided for connecting the radio station to a further digital database for music selections not stored in the common digital database.

Abstract: Electroacoustical transducing apparatus includes an input for receiving an audio electrical signal. A first electroacoustical transducer is constructed and arranged to radiate first sound waves in a first direction in a first frequency range in response to an audio electrical signal on the input. A second electroacoustical transducer is constructed and arranged to radiate sound energy in a second direction in a second frequency range. A third electroacoustical transducer is constructed and arranged to radiate sound energy in a third direction within the second frequency range.