| Harman International Industries, Incorporated Patent applications |
| Patent application number | Title | Published |
|---|
| 20120122279 | SYSTEM FOR CLAMPING HEAT SINK - A system for clamping a heat sink that prevents excessive clamping force is provided. The system may include a heat sink, a semiconductor device, a printed circuit) board, and a cover. The semiconductor device may be mounted onto the circuit board and attached to the cover. The heat sink may be designed to interface with the semiconductor device to transfer heat away from the semiconductor device and dissipate the heat into the environment. Accordingly, the heat sink may be clamped into a tight mechanical connection with the semiconductor device to minimize thermal resistance between the semiconductor device and the heat sink. To prevent excessive clamping force from damaging the semiconductor device, loading columns may extend between the cover and the heat sink. | 05-17-2012 |
| 20120121118 | SLOTTED WAVEGUIDE FOR LOUDSPEAKERS - A slotted waveguide for use with an electrodynamic transducer is described. The slotted waveguide has a transducer front surface for radiating acoustic energy from the electrodynamic transducer. The transducer front surface is concave and the electrodynamic transducer is operable to a desired high frequency. The slotted waveguide may include a body and a volume displacement element. The slotted opening has a width not substantially greater than a wavelength corresponding to the desired high frequency and the volume displacement element has a displacement surface that extends inward into the electrodynamic transducer and complements in shape the transducer front surface. | 05-17-2012 |
| 20120121105 | SYSTEM FOR NETWORKED ROUTING OF AUDIO IN A LIVE SOUND SYSTEM - A system to automate networked routing of audio in a live sound system includes a computing device having a processor and memory and in which the live sound system is configurable for a venue. The memory includes instructions executable by the processor to route audio signals over a network based on user selection of source audio signals from at least one transmitting audio device and on logical grouping of loudspeakers by the user from within a graphical user interface. The processor, for each receiving audio device channel of the group of loudspeakers (such as bandpass inputs), identifies power amplifiers and/or digital signal processors (DSPs) (which may be integrated within a powered loudspeaker) through which to route the selected source audio signals; and then routes the selected source audio signals from the selected transmitting audio device over the network to the receiving audio device channels through channels of the identified power amplifiers and/or DSPs. | 05-17-2012 |
| 20120119351 | SYSTEM FOR CLAMPING HEAT SINK - A system for clamping a heat sink that prevents excessive clamping force is provided. The system may include a heat sink, a semiconductor device, a printed circuit board, and a cover. The semiconductor device may be mounted onto the circuit board and attached to the cover. The heat sink may be designed to interface with the semiconductor device to transfer heat away from the semiconductor device and dissipate the heat into the environment. Accordingly, the heat sink may be clamped into a tight mechanical connection with the semiconductor device to minimize thermal resistance between the semiconductor device and the heat sink. To prevent excessive clamping force from damaging the semiconductor device, loading columns may extend between the cover and the heat sink. | 05-17-2012 |
| 20120106748 | SYSTEM FOR SIMULATED MULTI-GEAR VEHICLE SOUND GENERATION - A vehicle sound generator system is configured to generate a signal configured to drive one or more speakers produce sound waves simulating sounds associated with a desired engine type. The signal is based on one or more operating conditions of a vehicle. The vehicle sound generator system is configured to select sounds from a plurality of sounds based on the operating conditions of the vehicle. Each sound corresponds to a simulated sound of an engine operating in a respective gear. The vehicle sound generator system may generate the signal to drive the speakers to produce selected sounds to simulate shifting between the respective gears. | 05-03-2012 |
| 20120099750 | SPEAKER AND MIXER ASSEMBLY - A transportable audio system is described. The transportable audio system may include a speaker module and speaker mating module. The speaker module may include a backside mating edge and a backside interior inset from the backside mating edge. The backside mating edge may include a first attachment mechanism. The speaker mating module may include a frontside mating edge and a frontside face. The frontside mating edge may include a second attachment mechanism. The speaker mating module may be removably mountable to the speaker module via the first and second attachment mechanisms. | 04-26-2012 |
| 20120068739 | HIGHLY EFFICIENT CLASS-D AMPLIFIER - A simplistic low cost circuit that generates the necessary drive voltage for use in a source follower totem pole power switching circuit is described where the simplified gate drive circuit may have a dual charge pump and a complementary pair of low-power switching Mosfets. | 03-22-2012 |
| 20120063608 | SYSTEM FOR EXTRACTION OF REVERBERANT CONTENT OF AN AUDIO SIGNAL - A reverberant characteristic of an acoustic space is superimposed on an audio signal that is received by an apparatus. The apparatus decomposes the audio signal into an estimated original dry signal component and an estimated reverberant characteristic of the acoustic space. Estimation of the original dry signal component and the reverberant characteristic of the acoustic space is based on determination of an estimated impulse response of the acoustic space from the received audio signal. Once the audio signal is decomposed, the estimated original dry signal component and the estimated reverberant characteristic of the acoustic space may be independently modified by the apparatus. The modified or unmodified estimated original dry signal component and estimated reverberant characteristic of the acoustic space may be combined by the apparatus to produce one or more adjusted frequency spectra. | 03-15-2012 |
| 20120055650 | SYSTEM FOR CLAMPING HEAT SINK - A system for clamping a heat sink that prevents excessive clamping force is provided. The system may include a heat sink, a semiconductor device, a printed circuit board, and a cover. The semiconductor device may be mounted onto the circuit board and attached to the cover. The heat sink may be designed to interface with the semiconductor device to transfer heat away from the semiconductor device and dissipate the heat into the environment. Accordingly, the heat sink may be clamped into a tight mechanical connection with the semiconductor device to minimize thermal resistance between the semiconductor device and the heat sink. To prevent excessive clamping force from damaging the semiconductor device, loading columns may extend between the cover and the heat sink. | 03-08-2012 |
| 20120047435 | SYSTEM FOR CONFIGURATION AND MANAGEMENT OF LIVE SOUND SYSTEM - A computing system automates the configuration and management of a live sound system that includes a processor and memory for building in a GUI of a display a representation of the live sound system for a venue. The system loads a venue template that includes loudspeaker arrays and related properties including a setup configuration of the loudspeaker arrays and tuning data for constituent loudspeakers that are operable to provide an audio coverage pattern for the venue. The system overlays on top of the representation of the loudspeaker arrays a wiring circuit representation indicating interconnections of the loudspeakers that define bandpass inputs for each array. The system generates a plurality of amplifiers in the representation to drive the arrays, and associates amplifier channels of the amplifiers with the bandpass inputs. The amplifier channels include representations of output channels of DSPs coupled with respective amplifier channels. The system loads tuning data into respective representation of the DSP and/or amplifiers based on configurations of the associated loudspeakers to complete virtual configuration. The representations of the devices and connections may be matched with physical devices of the live sound system and the tuning data sent down to the physical DSPs and/or amplifiers for their configuration. | 02-23-2012 |
| 20120027238 | PHASING PLUG FOR A COMPRESSION DRIVER - A phasing plug for a compression driver includes a base portion and a hub portion. The base portion includes a first side, a second side, and a plurality of apertures extending between the first and second sides. The hub portion extends from the base portion along an axis. The hub portion includes an outer surface and a plurality of ribs disposed on the outer surface. A plurality of recesses are defined by the outer surface and respective pairs of adjacent ribs. At least one aperture fluidly communicates with at least one of the recesses. | 02-02-2012 |
| 20120008796 | DISTORTION COMPENSATION - A distortion compensation system minimizes distortion in an audio system by monitoring a supply voltage and adjusting a clipping threshold and/or compression knee. An adjustable gain circuit controls the gain of the audio signal according whether the audio signal exceeds a variable threshold. The variable threshold is adjusted within a threshold range based on the supply voltage. Distortion due to clipping of the audio signal is minimized while available power at any given time is maximized. | 01-12-2012 |
| 20110311065 | EXTRACTION OF CHANNELS FROM MULTICHANNEL SIGNALS UTILIZING STIMULUS - An approach and device for optimizing a sound system by extracting a two-channel stereo source out of a set of multiple channels with unknown frequency responses, crosstalk, time delays and sample rate by employing a digital test sequence that utilizes maximum-length-sequences (MLS) that is fed into the sound system and results in a reconstructed stereo source that may be further used as an input to a signal processor that performs improved speaker and room equalization. | 12-22-2011 |
| 20110304400 | HIGH EFFICIENCY BALANCED OUTPUT AMPLIFIER SYSTEM - A high efficiency amplifier system may include multiple output stages cooperatively operating to produce an amplified output signal. The amplifier system may be used in an audio system. The amplifier system may include a non-switchmode amplifier stage cooperatively operating with a switchmode amplifier stage to generate the amplifier output signal. The non-switchmode amplifier stage may selectively enable and disable the switchmode amplifier stage to optimize efficient operation. In addition, the switchmode amplifier stage may include multiple switching stages operated with interleave. The switching stages may be controlled to balance current output of the respective switching stages based on a measured current flow in at least one of the switching stages. | 12-15-2011 |
| 20110304397 | HIGH EFFICIENCY AUDIO AMPLIFIER SYSTEM - A high efficiency amplifier system may include multiple output stages cooperatively operating to produce an amplified output signal. The amplifier system may be used in an audio system. The amplifier system may include a non-switchmode amplifier stage cooperatively operating with a switchmode amplifier stage to generate the amplifier output signal. The non-switchmode amplifier stage may selectively enable and disable the switchmode amplifier stage to optimize efficient operation. In addition, the switchmode amplifier stage may include multiple switching stages operated with interleave. The switching stages may be controlled to balance current output of the respective switching stages based on a measured current flow in at least one of the switching stages. | 12-15-2011 |
| 20110231628 | SYSTEM FOR MEMORY INSTANTIATION AND MANAGEMENT - A system for memory instantiation in a programmable logic device (PLD) includes a computing device having a processor and memory coupled with the PLD. The processor is configured to receive memory parameters including at least a data width and a data depth. The processor is also configured to determine a number and sizes of block random access memory (BRAM) primitives required for data storage based on the memory parameters and based on one or more sizes of BRAM primitives available on the programmable logic device. In one example, the processor minimizes a size of the total number of BRAMs required for instantiation on the PLD. The processor is also configured to instantiate the determined number and corresponding sizes of the BRAM primitives in logic for configuration of the programmable logic device to include a device memory within the available BRAM primitives thereof corresponding to the determined number and sizes of the BRAM primitives. | 09-22-2011 |
| 20110231566 | MEMORY MANAGEMENT UNIT - A memory management unit (MMU) may buffer media stream samples of one or more media streams, such as audio and/or video streams, in a buffer. The MMU may determine how much time a media stream sample is to be buffered by comparing a value of a real-time clock with a timestamp associated with the media stream sample. The MMU may determine a target output block in the buffer for the media stream sample based on the period of a media clock and on the amount of buffer time that the media stream sample is to be buffered. The target output block is determined relative to an output block identified by a read address. The MMU may store the media stream sample in the target output block. The MMU may increase or decrease the read address at a rate determined by the media clock. | 09-22-2011 |
| 20110231565 | STREAM IDENTIFIER HASH TABLE - A system may route media stream samples in time-stamped packets to a media interface. The system may determine a hash value from a stream identifier that identifies a source media stream corresponding to the media stream samples. The hash value may be determined based on a combination of a first portion of the stream identifier and a second portion of the stream identifier. The system may determine whether the stream identifier identifies a subscribed media stream by looking up the hash value in a hash table. The system may route the media stream samples to a media interface if source media stream is a subscribed media stream. | 09-22-2011 |
| 20110231086 | VEHICLE NAVIGATION SYSTEM - A system and method is provided for identifying and generating a route that provides a driver with an exhilarating ride. In an example method, the navigation system obtains location data for routes between a starting and ending location. The location data is analyzed by identifying points of inflection of the curved road portion. At least one curved segment is identified as being road portions between the points of inflection. A linear distance, L | 09-22-2011 |
| 20110228945 | AUDIO POWER MANAGEMENT SYSTEM - An audio power management system manages operation of audio devices in an audio system. The audio power management system includes a parameter computer, a threshold comparator and a limiter. Audio signals generated with the audio system may be provided to the audio power management system. Based on a measured actual parameter of the audio signal, such as a real-time actual voltage and/or a real-time actual current, the parameter computer can derive estimated operational characteristics of audio devices, such as a loudspeaker included in the audio system. The threshold comparator may use the estimated operational characteristics to develop a threshold and manage operation of one of more devices in the audio system by monitoring the measured actual parameter, and selectively directing the limiter to adjust the audio signal, or another device in the audio system to protect or optimize performance. | 09-22-2011 |
| 20110228888 | MEDIA CLOCK RECOVERY - A system recovers a local media clock from a master media clock based on time-stamped packets received from a transmitter. The packets may include audio, video, or a combination of both, sampled at a rate determined by the master media clock at the transmitter. Timestamps in the packets may be based on values of a remote real-time counter at the transmitter that is synchronized with a local real-time counter at a receiver. The local media clock may be syntonized with the master media clock through the clock periods. The clocks may be synchronized by syntonizing the clocks and adjusting the phase of the local media clocks based on timestamps and a real-time counter. | 09-22-2011 |
| 20110228768 | MEDIA EXTRACTOR - A system generates one or more media streams from time-stamped packets received over a network. The packets may include audio, video, or a combination of both, sampled at a rate determined by a master media clock at a transmitter of the time-stamped packets or at some other node on the network. Timestamps in the packets may be presentation times based on values of a remote real-time clock at the transmitter that is synchronized with a local real-time clock at a receiver. The system may generate the media streams from the media stream samples and present the sampled data according to the presentation times. | 09-22-2011 |
| 20110168480 | PHASE PLUG AND ACOUSTIC LENS FOR DIRECT RADIATING LOUDSPEAKER - A phase plugs or acoustic lens improves the directional audio performance of a loudspeaker. Application of the improved directional audio performance to a sound system in a listening area may improve the performance of the audio system. Configuration of the acoustic lens or phase plug may include both symmetrical and asymmetrical features to provide an improved frequency response and directivity. The improved loudspeaker may provide improved an improved listing location, for example, in a vehicle. | 07-14-2011 |
| 20110153049 | ISOCHRONOUS AUDIO NETWORK SOFTWARE INTERFACE - A computer system includes a network interface that transmits and/or receives packets over a network. The packets may include isochronous audio packets and data packets. The computer system may have an operating system in which isochronous audio software is executable to extract audio data from the isochronous audio packets, or format audio data into isochronous audio packets. The system may also include other software executable within the operating system substantially in parallel with the isochronous audio software. The other software may extract data from the data packets. | 06-23-2011 |
| 20110116642 | Audio System with Portable Audio Enhancement Device - A portable audio enhancement device is configured for enhancing audio signals, and may be utilized in an audio system. The audio system may include a portable audio source, the audio enhancement device, an audio playback device, and a loudspeaker. The audio enhancement device receives audio signals from the audio source and produces enhanced audio signals. The audio playback device receives the enhanced audio signals and outputs the enhanced audio signals to the loudspeaker for playback. Enhancement of the audio signals may be based on an analysis performed by the audio enhancement device by measuring sample audio signals derived from the sound outputted from the loudspeaker. | 05-19-2011 |
| 20110103606 | MODULAR HEADPHONE SYSTEM - A modular headphone system includes an ear-mountable speaker, an audio signal-carrying line coupled to the ear-mountable speaker, and an electrical connector coupled to the audio signal-carrying line. The electrical connector is configured for electrically coupling to a plurality of different types of audio signal-carrying devices. The electrical connector may include a quick disconnect feature configured for securing the electrical connector to the audio signal-carrying device. A modular audio system includes a headphone system and an audio signal-carrying device coupled to the headphone system. The audio signal-carrying device may be disconnected from the headphone system, and another audio signal-carrying device of a different type may be coupled to the headphone system. | 05-05-2011 |
| 20110093104 | ARTIFICIAL AMBIANCE PROCESSING SYSTEM - An apparatus and method simulates more accurately the natural statistics of a physical reverberation process. A new filter design is provided having a comb shaped group delay. Gain minimums at a plurality of frequencies are combined with a delay line to create a constant reverberation time independent of frequency while allowing for temporal spreading. In addition, the connection topology between the plurality of energy transmission networks is temporally randomized to facilitate energy distribution within the reverberation apparatus. Both the temporal and spectral responses are actively changed on each iteration of the energy recirculation. By making the response have a high echo density and a lack of spectral coloration in the decay, the illusion of a natural process is enhanced. | 04-21-2011 |
| 20110089952 | PUSH-BUTTON TESTING SYSTEM - A system for testing a push-button switch is provided. The system for testing a push-button switch includes a switch test device. The switch test device has a flexible tab attached to a pushing member at an end of the flexible tab. A sensor is attached to the flexible tab. The sensor generates a signal that changes relative to a deformation of the flexible tab. A data collection system is connected to the switch test device and receives signals from the sensor. | 04-21-2011 |
| 20110088024 | SOFTWARE UPDATES VIA DIGITAL AUDIO MEDIA - Systems and methods for processing encoded digital data for programming a device to be re-programmed in an audio playback system. The system includes an audio media source containing digital data having audio data or encoded data in an audio data format. An audio media reader reads the digital data from the audio media source. A stream detector receives the digital data from the audio media reader and detects whether the received digital data includes encoded data formatted as audio data or audio data. An audio receiver device receives the audio data and processes the audio data for playback. A device to be re-programmed uses the encoded data formatted as audio data. | 04-14-2011 |
| 20110085692 | DUAL COMPRESSION DRIVERS AND PHASING PLUGS FOR COMPRESSION DRIVERS - A phasing plug includes a base portion including an input side, an output side, a plurality of entrances on the input side, a plurality of exits on the output side arranged about a central axis, and a plurality of channels fluidly interconnecting the entrances with the respective exits. Each corresponding entrance, channel and exit establish an acoustical path from the input side to the output side that is non-radial relative to the central axis. Two phasing plugs may be provided in a dual compression driver. | 04-14-2011 |
| 20110081032 | MULTICHANNEL AUDIO SYSTEM HAVING AUDIO CHANNEL COMPENSATION - A multichannel compensating audio system includes first and second compensation channels to psychoacoustically minimize deviations in a target response, to psychoacoustically move the physical position of a speaker and/or to psychoacoustically provide a substantially equal magnitude of sound from a plurality of speakers in a plurality of different listening positions. The first compensation channel may include a series connected delay circuit, a level adjuster circuit and a frequency equalizer circuit that generates a first compensated audio signal from a first audio signal. The second compensation channel may include a series connected delay circuit, a level adjuster circuit and a frequency equalizer circuit that generates a second compensated audio signal from a second audio signal. A first summing circuit is configured to receive at least the first audio signal and the second compensated audio signal and generate a first output signal for provision to a first speaker. A second summing circuit is configured to receive the second audio signal and the first compensated audio signal and generate a second output signal for provision to a second speaker. The first and second output signals may be output by the first and second speakers into a listening space and are acoustically perceived by a listener. | 04-07-2011 |
| 20110081024 | SYSTEM FOR SPATIAL EXTRACTION OF AUDIO SIGNALS - A sound processing system receives an audio input signal that includes at least two different input channels of audio content. The sound processing system dissects the audio input signal to separate sources of audible sound included in the audio input signal into sound source vectors. Separation of the sources of audible sound into sound source vectors may be based on a perceived location of each of the sources of audible sound within a listener perceived sound stage. The sound source vectors may represent spatial slices across the listener perceived sound stage that may be individually and independently processed with the sound processing system. Following processing, the sound source vectors may be selectively assembled to form an audio output signal having output channels used to drive respective loudspeakers. Since the sources of audible sound are separated and independent, the audible sound sources may be included on any one or more of the output channels. | 04-07-2011 |
| 20110057657 | PUSH-BUTTON TESTING SYSTEM - A push-button switch test device having a flexible tab fixedly attached to a pushing member. The flexible tab is made of a flexible material and includes a deformation sensitive resistor mounted on a surface. The push-button switch test device may be used to test a push-button by imposing a known force on the flexible tab while receiving a signal level across the deformation sensitive resistor. As the known force pushes on the flexible tab, the signal level indicates when the push-button has engaged. The force may then be reversed to permit sensing of the disengagement of the switch. Configurations of a plurality of push-button switch test devices may be arranged in a test frame that mirrors a configuration of push-button switches. | 03-10-2011 |
| 20110035217 | SPEECH-DRIVEN SELECTION OF AN AUDIO FILE - A system and method for detecting a refrain in an audio file having vocal components. The method and system includes generating a phonetic transcription of a portion of the audio file, analyzing the phonetic transcription and identifying a vocal segment in the generated phonetic transcription that is repeated frequently. The method and system further relate to the speech-driven selection based on similarity of detected refrain and user input. | 02-10-2011 |
| 20100318917 | NETWORKED AUDIO/VIDEO SYSTEM - A system for configuring an audio/video (AV) system includes a computing device having a processor to enable a user, with a user interface of the computing device, to configure the AV system. The processor may enable the user to draw output zones to create a representation of a geographical layout of a venue in which the AV system is located. The processor may enable the user to place transmitting and receiving AV devices within the output zones that substantially represent physical locations thereof within the venue. The processor may enable the user to logically associate receiving AV device channels of one or more receiving AV devices within an output zone. The processor may also enable the user to select which of a number of source AV signals from transmitting AV devices the user wants to route to the associated output zone. The processor routes the source AV signals from one or more transmitting AV devices over a network to the one or more receiving AV device channels, such that the one or more receiving AV device channels are processed according to the output zone as configured by the user in the user interface. | 12-16-2010 |
| 20100318911 | SYSTEM FOR AUTOMATED GENERATION OF AUDIO/VIDEO CONTROL INTERFACES - A system for automating generation of an audio/video (AV) control interface includes a computing device having a processor to enable a user, with a user interface of the computing device, to configure the AV system. The processor may enable the user to draw output zones to create a representation of a geographical layout of a venue in which the AV system is located. The processor may enable the user to place transmitting and receiving AV devices within the output zones that substantially represent physical locations thereof within the venue. The processor may enable the user to logically associate receiving AV device channels of receiving AV devices within an output zone. The processor assigns parameters of the associated AV devices to a control interface for user control thereof. To do so, the processor identifies controllable parameters associated with the AV devices associated with the output zone. The processor assigns a data storage structure associated with each respective controllable parameter to the control interface. The processor launches the control interface in an application window having integrated therewith the controllable parameters and a menu selection of a source AV signal. | 12-16-2010 |
| 20100310111 | LOUDSPEAKER HAVING AN INTERLOCKING MAGNET STRUCTURE - A magnet structure for use with a loudspeaker has an interlocking mechanism. The magnet structure can include a magnet, a shell pot and at least one core cap. The shell pot can contain the magnet in its hollow interior. The magnet can be a single magnet or double magnets. The core cap has two surfaces. For a single magnet, one surface of the core cap faces the magnet. For double magnets, the core cap can be vertically disposed between the two magnets. The magnet, the core cap and the shell pot can interlock with one another such that a position of the magnet relative to the core cap and the shell pot can be rigidly preserved. The magnet can be configured to be, for example, overlapped, inserted, staked and/or engaged with at least one of the shell pot or the core cap. | 12-09-2010 |
| 20100290643 | EFFICIENCY OPTIMIZED AUDIO SYSTEM - An automated audio tuning system may optimize an audio system for power efficiency when performing automated tuning of the audio system to optimize acoustic performance. The system may establish any number of different power efficiency weighting factors to provide a balance between acoustic performance and power efficiency during operation. The power efficiency weighting factors may range from representing optimizing power efficiency with constrained optimization of acoustic performance to optimized acoustic performance with minimized regard for power efficiency. For each of the efficiency weighting factors, the system may generate operational parameters, such as filter parameters, to achieve a target acoustic response while maintaining a determined level of power efficiency. | 11-18-2010 |
| 20100290635 | SYSTEM FOR ACTIVE NOISE CONTROL WITH ADAPTIVE SPEAKER SELECTION - An active noise control system generates an anti-noise signal to drive a first speaker group including at least one speaker to produce sound waves to destructively interfere with an undesired sound in at least one quiet zone. The active noise control system receives error signals representative of a combination of undesired sound and destructively interfering sound waves produced by the first speaker group. The active noise control system may select a second speaker group to replace the first speaker group based on the error signals. | 11-18-2010 |
| 20100278346 | SPECTRAL MANAGEMENT SYSTEM - A spectral management system may be used in an audio system to receive and process audio signals having multiple distributed audio channels, such as a right, left, center, right side, left side, right rear and left rear channels. The spectral management system may separate and route a frequency range of audio content included in one or more of the distributed audio channels to other distributed audio channels. The separated and routed frequency range of audio content may be combined with audio content present on the other distributed audio channels to which the separated frequency range of audio content is routed. Separation, routing and combination may include bass audio content routing, mid-bass audio content routing, subwoofer audio content routing and treble audio content routing. | 11-04-2010 |
| 20100272270 | SELF-CALIBRATING LOUDSPEAKER SYSTEM - Systems and methods for calibrating a loudspeaker with a connection to a microphone located at a listening area in a room. The loudspeaker includes self-calibration functions to adjust speaker characteristics according to effects generated by operating the loudspeaker in the room. In one example, the microphone picks up a test signal generated by the loudspeaker and the loudspeaker uses the test signal to determine the loudspeaker frequency response. The frequency response is analyzed below a selected low frequency value for a room mode. The loudspeaker generates parameters for a digital filter to compensate for the room modes. In another example, the loudspeaker may be networked with other speakers to perform calibration functions on all of the loudspeakers in the network. | 10-28-2010 |
| 20100266149 | IN-WALL SUB-WOOFER WITH HIGH-VOLUME DISPLACEMENT - An in-wall speaker system having at least one pair of active transducers mounted in a wall section. The active transducers may be mounted in at least one enclosure. Each active transducer has a sound radiating surface. Each active transducer is also mounted substantially perpendicular to a surface of the wall section with the sound radiating surfaces substantially parallel to each other. The sound radiating surfaces may be facing each other or away from each other. The in-wall speaker system may also include one or more pairs of passive radiators to generate sound from sound pressure generated by the active transducers. The pairs of speakers in the wall section may be mounted vertically or horizontally within the wall, with a slot or a vent at the opening at the space between the speaker pairs. | 10-21-2010 |
| 20100266134 | SYSTEM FOR ACTIVE NOISE CONTROL WITH AN INFINITE IMPULSE RESPONSE FILTER - An active noise control (ANC) system includes at least one infinite impulse response filter (IIR). The IIR filter generates an output signal based on an input signal representative of an undesired sound. The ANC system generates an anti-noise signal based on the output signal of the IIR filter. The anti-noise signal is used to drive a speaker to generate sound waves to destructively interfere with the undesired sound. The ANC system includes an update system to generate update coefficients. The update system determines the stability of the update coefficients. Coefficients of the IIR filter are replaced with the update coefficients. The update system generates a set of update coefficients for each sample of the input signal. | 10-21-2010 |
| 20100260345 | SYSTEM FOR ACTIVE NOISE CONTROL BASED ON AUDIO SYSTEM OUTPUT - An active noise control (ANC) system is configured to generate at least one anti-noise signal configured to drive a speaker to generate sound waves to destructively interfere with an undesired sound present in a target space. The at least one anti-noise signal is adjusted based an output signal of an audio system. The at least one anti-noise signal may be adjusted based on at least one of a volume level of the audio system, a power level of at least one predetermined frequency or frequency range of the output signal of the audio system, frequency content of an output signal of the audio system. The ANC system receives an error signal to adjust generation of the at least one anti-noise signal. The error signal is adjusted to compensate for adjustment of the at least one anti-noise signal based on the output signal of the audio system. | 10-14-2010 |
| 20100246848 | MOTIONAL FEEDBACK SYSTEM - An audio amplifier is operated in an audio system with optimized source impedance to minimize distortion in a loudspeaker that is paired with the audio amplifier. The audio amplifier provides an amplified audio signal to drive the loudspeaker. A variable output impedance of the audio amplifier is controlled using a feedback control loop to allow negative output impedance at low frequencies that changes to positive output impedance at higher frequencies. The change from negative output impedance to positive output impedance occurs at a determined threshold frequency or determined transitional frequency band. | 09-30-2010 |
| 20100229208 | VEHICULAR DIGITAL AUDIO RECORDER ENERGY USAGE MONITOR - The present invention relates to the use of a power control module with a recorder for recording audio programming and accessing audio programming that is part of a vehicle entertainment system (VES) where the power control module assures the energy used by the recorder when the vehicle is off does not drain the power supply beyond a predetermined level. | 09-09-2010 |
| 20100229207 | VEHICULAR DIGITAL AUDIO RECORDER USER INTERFACE - The present invention relates to the use of a recorder that is part of a vehicle entertainment system (VES) for recording audio programming and accessing recorded audio programming, where external controls for the recorder may be located on the steering wheel of the vehicle, allowing a driver to safely configure the VES for recording audio programming and accessing the recorded audio programming. | 09-09-2010 |
| 20100215204 | SPEAKER ISOLATION SYSTEM - A loudspeaker mounting assembly for mounting a loudspeaker in an isolated relation to a structure includes an enclosure and a plurality of interface elements composed of a vibration-damping material. The enclosure has an interior for receiving the loudspeaker and includes at least two spaced-apart support members. Each of the at least two support members includes a support member outer surface and an inner surface extending from the support member outer surface into the support member. The inner surface defines a support member bore. Each interface element includes an interface element outer surface. Each interface element is disposed in a corresponding one of the support member bores and at least partially extends out from the respective support member outer surface, where each interface element outer surface contacts the respective inner surface of the support member. | 08-26-2010 |
| 20100214022 | BI-DIRECTIONAL AND ADJUSTABLE CURRENT SOURCE - A Bi-Directional and Adjustable Current Source (“BACS”) for providing an amplifier input with a voltage signal that is linear, where an output of the BACS and the amplifier input are shunted with a capacitor, is described. The BACS may include a first switch in signal communication with a high voltage reference and a first current source in signal communication with the first switch. The BACS may also include a second switch in signal communication with a low voltage reference and a second current source in signal communication with the second switch. The BACS may further include a directional current element in signal communication with both the first current source, the second current source, the output of the BACS, the amplifier input, and the capacitor, where the directional current element is configured to prevent current flow from the output BACS to the first current source. | 08-26-2010 |
| 20100205223 | SYSTEM FOR BROADCAST INFORMATION DATABASE - A database system includes a processor configured to receive broadcasts according to a plurality of broadcast formats. The processor determines broadcast information associated with each received broadcast. The processor stores a database entry for each received broadcast within a database stored in the memory. Each database entry is indicative of the broadcast information associated the received broadcast. The processor continuously populates the database with broadcast information associated with received broadcasts. The database is user-accessible, allowing database entries to be viewed and altered. Ratings for various broadcast information are user-provided allowing preferred broadcast content to be user-designated based on the broadcast information. The ratings are used to notify a user of preferred broadcast content being broadcast according to at least one of the broadcast formats allowing the user to select receipt of the preferred broadcast content while available. | 08-12-2010 |
| 20100177905 | SYSTEM FOR ACTIVE NOISE CONTROL WITH PARALLEL ADAPTIVE FILTER CONFIGURATION - An active noise control system includes a plurality of adaptive filters. The plurality of adaptive filters each receives an input signal representative of an undesired sound. The adaptive filters may each generate an output signal based on the input signal. The output signals are used to generate an anti-noise signal configured to drive a speaker to produce sound waves to destructively interfere with the undesired sound. | 07-15-2010 |
| 20100141585 | MID-KEYBOARD-MONITOR COMPUTER-BASED AUDIO I/O DEVICE - A system and device for placement between a keyboard and monitor on a work surface that routes cables and provides access to controls, where the system and device rest in a first position for use and a second position for access to ports and cables. | 06-10-2010 |
| 20100124337 | QUIET ZONE CONTROL SYSTEM - An active noise control system generates an anti-noise signal to drive a speaker to produce sound waves to destructively interfere with an undesired sound in a quiet zone. The anti-noise signal is generated with an adaptive filter having filter coefficients. The coefficients of the adaptive filter may be adjusted based on a first filter adjustment from a first listening region, and a second filter adjustment from a second listening region. A first weighting factor may be applied to the first filter adjustment, and a second weighting factor may be applied to the second filter adjustment. The first and second weighting factors may dictate the location and size of the quiet zone as being outside or partially within at least one of the first listening region and the second listening region. | 05-20-2010 |
| 20100124336 | SYSTEM FOR ACTIVE NOISE CONTROL WITH AUDIO SIGNAL COMPENSATION - An active noise control system generates an anti-noise signal to drive a speaker to produce sound waves to destructively interfere with an undesired sound in a targeted space. The speaker is also driven to produce sound waves representative of a desired audio signal. Sound waves are detected in the target space and a representative signal is generated. The representative signal is combined with an audio compensation signal to remove a signal component representative of the sound waves based on the desired audio signal and generate an error signal. The active noise control adjusts the anti-noise signal based on the error signal. The active noise control system converts the sample rates of an input signal representative of the undesired sound, the desired audio signal, and the error signal. The active noise control system converts the sample rate of the anti-noise signal. | 05-20-2010 |
| 20100104117 | CONSTANT-BEAMWIDTH LOUDSPEAKER ARRAY - A loudspeaker is provided for receiving an incoming electrical signal and transmitting an acoustical signal that is directional and has a substantially constant beamwidth over a wide frequency range. The loudspeaker may include a curved mounting plate that has curvature over a range of angles. The loudspeaker may include an array of speaker drivers coupled to the mounting plate. Each speaker driver may be driven by an electrical signal having a respective amplitude that is a function of the speaker driver's respective location on the mounting plate. The function may be a Legendre function. Alternatively, the loudspeaker may include a flat mounting plate. In this case, the respective electrical signal driving each speaker may have a phase delay that virtually positions the speaker onto a curved surface. | 04-29-2010 |
| 20100019847 | AMPLIFIER EMPLOYING INTERLEAVED SIGNALS FOR PWM RIPPLE SUPPRESSION - An amplifier having improved distortion characteristics is set forth. The amplifier includes an interleaved PWM amplifier that generates interleaved PWM pulses in response to a modified input signal and one or more carrier signals. The interleaved PWM pulses of the amplifier are used to drive a power stage, such as an opposed current power stage. The amplifier also includes an interleaved PWM generator that provides interleaved PWM pulses in response to the modified input signal and one or more further carrier signals. The carrier signals used by the PWM generator may differ in phase from the carrier signals used by the interleaved PWM amplifier to generate its interleaved PWM pulses. One or more feedback circuits are employed in the generation of the modified input signal. More particularly, the feedback circuit(s) generates the modified input signal based on an input signal that is to be amplified and the interleaved PWM pulses of the interleaved PWM generator. | 01-28-2010 |
| 20100019846 | AMPLIFIER EMPLOYING INTERLEAVED SIGNALS FOR PWM RIPPLE SUPRESSION - An amplifier having improved distortion characteristics is set forth. The amplifier includes an interleaved PWM amplifier that generates interleaved PWM pulses in response to a modified input signal and one or more carrier signals. The interleaved PWM pulses of the amplifier are used to drive a power stage, such as an opposed current power stage. The amplifier also includes an interleaved PWM generator that provides interleaved PWM pulses in response to the modified input signal and one or more further carrier signals. The carrier signals used by the PWM generator may differ in phase from the carrier signals used by the interleaved PWM amplifier to generate its interleaved PWM pulses. One or more feedback circuits are employed in the generation of the modified input signal. More particularly, the feedback circuit(s) generates the modified input signal based on an input signal that is to be amplified and the interleaved PWM pulses of the interleaved PWM generator. | 01-28-2010 |
| 20100008648 | AUDIO ONLY PLAYBACK OF A DISK HAVING BOTH AUDIO AND VIDEO RECORDINGS - A system and method for playing audio only in a disk player. The disc player is configured to read data from disks formatted according to a selected audio and video standard. The system includes a file reader to read files of audio and video files based on the audio and video standard. A stream parser identifies audio data, video data and sub-picture data. An audio decoder decodes the audio data according to the audio standard. A video stub receives the video data and leaves the video data unprocessed. A sub-picture menu processor extracts menu information. A user interface system to use the menu information to configure at least one user input to play audio-only from the disk according to the menu information. | 01-14-2010 |
| 20090324000 | SPEAKER SURROUND STRUCTURE FOR MAXIMIZING CONE DIAMETER - A surround that is generally arched in shape and that includes a radial exterior flange that extends downward from exterior side of the arched portion of the surround and that adhesively attaches to the inner wall or edge of the mounting ring of the frame of the loudspeaker. | 12-31-2009 |
| 20090316930 | WIDE-BAND EQUALIZATION SYSTEM - A Wide-band Equalization System (“WBES”) based on near- and far-field measurement data. The WBES includes a subwoofer equalizer having an FIR filter together with decimator and interpolator filters for processing low frequency signals. The WBES may also include satellite channels for processing mid- and high-frequency signals, where each satellite channel includes cascaded IIR filters that process mid-frequency and high-frequency signals, respectively. The WBES may also include a DSP that performs the functions required by the IIR and FIR filters. | 12-24-2009 |
| 20090310809 | PHASING PLUG - A phasing plug for a compression driver includes a base portion and a hub portion. The base portion includes a first side, a second side, and a plurality of apertures extending between the first and second sides. The hub portion extends from the base portion along an axis. A plurality of channels formed on the second side of the base portion, each channel extending from the hub portion to a corresponding one of a plurality of apertures extending between the first and second sides, the apertures formed to define lines cutting diagonally across the annular section. | 12-17-2009 |
| 20090310808 | WAVEGUIDE - A waveguide configured to function as a high frequency waveguide for a high frequency sound source mounted to the waveguide, and to function as an acoustical low pass filter for a low frequency sound source mounted behind the waveguide in a multi-way loudspeaker system. The waveguide includes openings that overlay the vibrating surface of the low frequency source. The openings are configured by selection of various geometrical parameters to tailor filtering characteristics as desired. | 12-17-2009 |
| 20090267656 | PRECISION TRIANGLE WAVEFORM GENERATOR - A triangle waveform generator is set forth that comprises a capacitive element, a regulator, and a control circuit. The regulator is configured to charge the capacitive element in responsive to a first control signal and to discharge the capacitive element in response to a second control signal. The control circuit is responsive to a reference waveform to generate the first and second control signals. In one example, the control circuit generates the first and second control signals in response to the amplitude, frequency, phase, and symmetry of the reference waveform. | 10-29-2009 |
| 20090232332 | CLASS-D TRANSCONDUCTANCE AMPLIFIER - The invention relates to a class-D audio amplifier. The class-D audio amplifier is configured in a current feedback mode as a voltage-controlled current source and a passive inductor/capacitor (LC) reconstruction filter. A portion of the passive LC reconstruction filter is situated in a feedback loop to an error amplifier. | 09-17-2009 |
| 20090230273 | SUSPENSION SYSTEM - A system is provided for suspending a plurality of line array loudspeakers. The suspension system includes a rigging bar having an engaging member, such as a pivotal member, positioned near one end of the rigging bar. The engaging member includes a free end capable of extending outward past the end of the rigging bar in which the engaging member is positioned. The end of the rigging bar opposite the pivotal member is designed to releasably receive an engaging member of an adjacent rigging bar. The free end of the engaging member of the rigging bar may include a hole that aligns with holes positioned in the receiving end of the rigging bar. The engaging member of one rigging bar may then be secured to an adjacent rigging bar by aligning holes of the engaging member of a first rigging bar with the holes in the receiving end of a second rigging bar and inserting a release pin through the aligned holes. | 09-17-2009 |
| 20090168360 | CLAMP FOR ELECTRICAL DEVICES - An assembly for clamping electrical components against a heat-dissipating surface of a heat sink may include the heat sink, one or more electrical components, two or more springs, and a fastener. Each of the springs may include a first surface, and a second surface opposite the first surface. The second surface of each of the springs may include an attachment region and two contact regions. The attachment region may be between the two contact regions. The second surface of one of the springs may overlap the first surface of another one of the springs. Each of the springs may be positioned to hold the electrical components against the heat dissipating surface of the heat sink. Each of the two contact regions of each of the springs may be positioned to hold the electronic components against the heat-dissipating surface. The fastener may couple the springs together in the attachment region of each of the springs and may further couple the springs to the heat sink. | 07-02-2009 |
| 20090164473 | VEHICLE INFOTAINMENT SYSTEM WITH VIRTUAL PERSONALIZATION SETTINGS - The personalized content system of the system combines a summary music identification value creation and identification algorithm that represents a mathematical summary music identification of a song, an audio file, or other relational music criteria and data (e.g. title, artist, genre, style, beats per minute, etc.) or any combination thereof. The derived value represents the musical taste or style attributes of a song or style. The analysis and generation of the summary music identification value is intended to take place while outside the vehicle where attention can be paid and vehicle distraction and safety is not an issue. A user can generate a single summary music identification value or can generate multiple summary music identification values for different criteria. In other cases, summary music identification values can be defined for genre, but with a much more personal touch possible than with fixed playlist radio stations. In another embodiment, a user can obtain and use someone else's summary music identification value (e.g. a celebrity, artist, friend, etc.) and use it with the system. | 06-25-2009 |
| 20090147975 | SPATIAL PROCESSING STEREO SYSTEM - A spatial processing stereo system (“SPSS”) that receives audio signals and a limited number of user input parameters associated with the spatial attributes of a room, such as “room size”, “stage distance”, and “stage width”. The input parameters are used to define a listening room and generate coefficients, room impulse responses, and scaling factors that are used generate additional surround signals. | 06-11-2009 |
| 20090123005 | MULTIPLE MAGNET LOUDSPEAKER - A loudspeaker provides increased magnetic flux from multiple magnets to drive voice coils to generate sound. The loudspeaker is formed as a smaller profile and reduced weight package. The loudspeaker includes a dual pole, first and second magnets, first and second front plates, and first and second gaps. The polarities of the first and second magnets are aligned in the same direction. The first and second magnets may be disk or ring-shaped and may be coupled to a flange of the dual pole. The first and second gaps may be formed between the inner diameters of the first and second magnets and the dual pole. The magnetic flux produced by the first and second magnets may be combined, directed, and concentrated within the first and second gaps by the dual pole and the front plates. At least portions of a first and a second voice coil may be positioned within the first and second gaps, respectively, and diaphragms may be coupled to the first and second voice coils. | 05-14-2009 |
| 20090097753 | SYSTEM FOR A TEXT SPELLER - An apparatus may generate a text entry with a user interface. The apparatus may include a display, a user input device, a memory and a processor. The apparatus may display single character user input controls and multi-character user input controls on the display. Each of the single character user input controls and the multi-character user input controls may be buttons selectable with the user input device. A single character user input control may correspond to a single character and a multi-character user input control may correspond to a group of characters. The apparatus may display one of the multi-character user input controls in a display region and other user input controls outside of the display region. If the multi-character user input control is selected, the apparatus may replace the multi-character user input control with a second set of single character user input controls in an expanded display region. | 04-16-2009 |
| 20090074228 | LOUDSPEAKER CONE BODY - A loudspeaker cone body made of paper may include a chemically-bound nanomaterial, such as a carbon nanotube. The carbon nanotube may be chemically bound to a functionalizing agent having a chemical group chemically bound to one or more papermaking additives, such as a sizing agent or a wet strength agent, a dry strength agent, a resin or cellulose-containing papermaking stock material typically present in a paper loudspeaker cone body, such as pulp. Acoustic-related loudspeaker performance characteristics such as stiffness to weight ratio and an acoustic damping of the loudspeaker cone body may be altered by incorporation of the nanomaterials chemically bound to the loudspeaker cone body. | 03-19-2009 |
| 20080319564 | SOUND PROCESSING SYSTEM FOR CONFIGURATION OF AUDIO SIGNALS IN A VEHICLE - A sound processing system for a vehicle includes a sound processor that is configured to mix at least one real audio input signal to form at least one virtual output signal. At least one audio signal that is available to drive at least one loudspeaker may be formed using the combination of the virtual output signal and the real audio input signal. The virtual output signal may be post processed to form a predetermined frequency range of the audio signal prior to being combined with the real audio input signal. The audio signal may be created by mixing the real audio input signal with the post processed virtual output signal. Alternatively, the audio signal may be formed by mixing the real audio input signal to form a real audio output signal, and then summing the real audio output signal with the post processed virtual output signal. Mixing may be performed with a crossbar mixer included in the sound processor. | 12-25-2008 |
| 20080317257 | SOUND PROCESSING SYSTEM FOR CONFIGURATION OF AUDIO SIGNALS IN A VEHICLE - A sound processing system for a vehicle includes a sound processor that is configured to mix at least one real audio input signal to form at least one virtual output signal. At least one audio signal that is available to drive at least one loudspeaker may be formed using the combination of the virtual output signal and the real audio input signal. The virtual output signal may be post processed to form a predetermined frequency range of the audio signal prior to being combined with the real audio input signal. The audio signal may be created by mixing the real audio input signal with the post processed virtual output signal. Alternatively, the audio signal may be formed by mixing the real audio input signal to form a real audio output signal, and then summing the real audio output signal with the post processed virtual output signal. Mixing may be performed with a crossbar mixer included in the sound processor. | 12-25-2008 |
| 20080278984 | AUTOMATIC ZERO VOLTAGE SWITCHING MODE CONTROLLER - A switching DC to AC power converter includes an automatic zero voltage switching (ZVS) mode controller. The automatic zero voltage switching mode controller may adjust a ZVS dead-time in accordance with a range of load currents being supplied by the power converter that range from quiescent conditions to a predetermined loading level of the power converter. The variable ZVS dead-time may be larger nearer to quiescent conditions, and become progressively smaller as load currents increase. Outside a predetermined range of load currents, the variable ZVS dead-time may be disabled or minimized. | 11-13-2008 |
| 20080273734 | COMBINED POWER AND AUDIO DOCK FOR HANDHELD DEVICE - A combined power and audio dock for a handheld electronic device provides an integrated solution to the multiple uses of multifunction devices such as mobile telephones with built-in music players. The dock is configured with a recess into which the handheld device is docked so that all four exterior edges of the device are surrounded by the dock. This enables the dock to engage with any controls, jacks and ports along any edge of the device, and includes loudspeakers that can amplify the audio output of the device. The device is docked in an intentional assembly sequence that enables power and audio connectors to engage corresponding jacks on common, adjacent or opposing edges of the handheld device. Removal is accomplished in a reverse sequence. | 11-06-2008 |
| 20080247593 | LOUDSPEAKER MOUNTING ASSEMBLY - A loudspeaker mounting assembly includes a frame, a sleeve, and a tilt-angle adjustment mechanism. The frame may include an outer frame, an inner frame rotatable about a frame axis relative to the outer frame, and a frame wall extending away from a rear side. The sleeve is coupled to the inner frame at a pivot axis and is tiltable to a plurality of tilt angles relative to the inner frame. The tilt-angle adjustment mechanism is engageable with the sleeve to enable selection of a desired tilt angle. A loudspeaker may be mounted to the sleeve such that the loudspeaker may be swiveled about the frame axis and tilted about the pivot axis. | 10-09-2008 |
| 20080247575 | DIRECTIONAL LOUDSPEAKER TO REDUCE DIRECT SOUND - A directional loudspeaker provides an enhanced listening environment by producing an indirect sound field of greater amplitude than that of the direct sound field. The directional loudspeaker includes loudspeaker elements positioned to provide a listener located below the loudspeaker elements with an impression of sound spaciousness in a vehicle environment. The loudspeaker elements may include baffles or acoustic lenses to deflect the indirect field away from the path to the listener position. The loudspeaker may also be operated with windows open by channeling the indirect sound field through an acoustic waveguide and deflector to the listener. A sound processor is also provided to accept a sound input, create an indirect and direct sound field, output the sound fields to loudspeaker elements, and also may provide electronic enhancement effects such as multi-channel sound or sound parameter adjustment. | 10-09-2008 |
| 20080232603 | SYSTEM FOR MODIFYING AN ACOUSTIC SPACE WITH AUDIO SOURCE CONTENT - An audio signal processing system is configured to separate an audio signal into a dry signal component and one or more reverberant signal components. The dry signal component and the reverberant signal components can be separately modified and then recombined to form a processed audio signal. Alternatively, the dry signal component may be combined with an artificial reverberation component to form the processed audio signal. Modification of the reverberation signal component and generation of the artificial reverberation component may be performed in order to modify the acoustic characteristics of an acoustic space in which the audio signal is driving loudspeakers. The audio signal may be a pre-recorded audio signal or a live audio signal generated inside or outside the acoustic space. | 09-25-2008 |
| 20080229249 | USER INTERFACE FOR MULTIFUNCTION DEVICE - A graphical user interface for use in connection with a device having navigation and media functionality includes a navigation interface and a media interface that each have having a plurality of screens adapted to facilitate interaction between a user and a navigation application and a media application, respectively. An application interface toggle button it is actuatable on at least one of the plurality of navigation interface screens and on at least one of the plurality of media interface screens. Actuation of the application interface toggle button from a navigation interface screen invokes display of a media interface screen, and actuation of the application interface toggle button from a media interface screen invokes display of a navigation interface screen. | 09-18-2008 |
| 20080205690 | LOUDSPEAKER MAGNETIC FLUX COLLECTION SYSTEM - A loudspeaker design delivers improved efficiency by reducing the power required from an audio source to produce sound. The loudspeaker includes a magnet housing, at least two magnets and a magnetic flux collector. The magnetic flux collector is coupled with and extends away from the magnet housing. Magnetic flux generated by the magnets is received and channeled by the magnetic flux collector and the magnet housing to an air gap included in the loudspeaker to maximize the availability of the magnetic energy of the magnets in the air gap. | 08-28-2008 |
