Abstract:
Processes and devices for equalizing an audio system that is adapted to use a loudspeaker to transduce test audio signals into test sounds. The processes and devices can involve the use of infrared signals to convey information in one or both directions between the audio system and a portable computer device that captures test sounds, calculates audio parameters that can be used in the equalization process, and transmits these audio parameters back to the audio system for its use in equalizing audio signals that are played by the audio system.

Description:
BACKGROUND 
       [0001]    This disclosure relates to equalizing audio systems. 
         [0002]    Audio systems use an audio signal source to generate sound from one or more transducers/loudspeakers. In equalized systems the frequency response is modified so as to provide higher quality sound in the room or listening area in which the audio system is located. For portable audio systems such as wireless speaker packages, the location can easily be changed. Such systems will provide better sound if they are equalized to their environment each time they are moved, or if the environment changes. 
       SUMMARY 
       [0003]    All examples and features mentioned below can be combined in any technically possible way. 
         [0004]    In one aspect a dongle that is adapted to be coupled to a portable computer device includes a microphone adapted to detect test sounds radiated by an audio system and an infrared transmitter adapted to transmit infrared signals to the audio system, where the transmitted infrared signals convey to the audio system audio parameters that are based on the detected test sounds. 
         [0005]    Embodiments may include one of the following features, or any combination thereof. The audio system may be a wireless speaker package. The transmitted infrared signals may also convey audio system control signals to the audio system. The dongle may also include a digital connector that is adapted to be coupled to the portable computer device. The digital connector may be a USB connector. The dongle may also include an analog connector that is configured to be coupled to the portable computer device. The analog connector may be a plug that is adapted to couple with an analog jack of the portable computer device. The audio parameters may include an equalization pattern that is appropriate to achieve a desired audio system frequency response. 
         [0006]    In another aspect a process for equalizing a first audio system that is adapted to use a loudspeaker to transduce test audio signals into test sounds includes capturing test sounds by a remote device, calculating, based on the captured test sounds, information that can be used to achieve a desired frequency response from the first audio system, wirelessly transmitting, by an infrared transmitter that is functionally associated with the remote device, and as a series of infrared signals, the calculated information, receiving, by an infrared receiver that is functionally associated with the first audio system, the transmitted infrared signals, translating, by the first audio system, the received infrared signals into an audio system equalization pattern that is appropriate to achieve a desired frequency response from the first audio system, and saving, in a memory of the first audio system, the speaker package equalization pattern. 
         [0007]    Embodiments may include one of the following features, or any combination thereof. The information that can be used to achieve a desired frequency response from the first audio system may be calculated by the remote device, or it may be calculated by a remote device such as a cloud-connected device. The process may also include providing feedback concerning the transmitted infrared signals, by the audio system, via audio played from the loudspeaker. The infrared transmitter may be part of a dongle that is adapted to be coupled to the remote device. The dongle may be adapted to be coupled to the remote device via an analog jack of the remote device. The remote device may be a smartphone or a second audio system, for example. The first and second audio systems may each be a wireless speaker package. 
         [0008]    In another aspect, a method that uses a portable computer device that is adapted to communicate with an audio system, where the audio system is adapted to use one or more loudspeakers to transduce audio signals into sound, includes receiving, by a microphone associated with the portable computer device while the portable computer device is at a first location in a listening space, sound from the audio system when the audio system plays test audio signals, determining a time delay between the audio signals and the receipt of the played test audio signals by the microphone, determining, based on the played test audio signals, a frequency response for the first location, and transmitting to the audio system, based on the frequency response, audio parameters that are appropriate to achieve a desired acoustic profile from the one or more loudspeakers of the audio system. 
         [0009]    Embodiments may include one of the following features, or any combination thereof. The audio parameters may be calculated by the portable computer device, or the audio parameters may be calculated by a remote computing device and then transmitted to the portable computer device. The information that is based on the frequency response may include one or more audio parameters that are calculated using the determined time delay. Determining a time delay may include correlating the test audio signals and microphone signals. The transmission to the audio system by the portable computer device may be wireless, and may use infrared signals. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is schematic block diagram of an audio system and a portable computer device that together can be used to equalize the audio system. 
           [0011]      FIG. 2  is schematic block diagram of another audio system and a smart phone with associated dongle that together can be used to equalize the audio system. 
       
    
    
     DETAILED DESCRIPTION 
       [0012]    An audio system can play higher quality sound if it is equalized to its surroundings. For portable audio systems such as wireless speaker packages, the location can easily be changed. Such systems will provide better sound if they are equalized to their environment each time they are moved, or if the environment changes. 
         [0013]    Audio system equalization is disclosed in U.S. Pat. No. 7,483,540, the disclosure of which is incorporated herein by reference. The subject patent discloses equalizing an audio system using a portable computer device that is moved to one or more locations in the room. Test sounds radiated by the audio system are received by the portable computer device. An equalization pattern is calculated by the portable computing device from an average room response from the various position responses. The equalization pattern is downloaded to the audio system, which then applies it to the audio signals that are transduced to sound waves. 
         [0014]    In the present disclosure, elements of figures are shown and described as discrete elements in a block diagram. These may be implemented as one or more of analog circuitry or digital circuitry. Alternatively, or additionally, they may be implemented with one or more microprocessors executing software instructions. The software instructions can include digital signal processing instructions. Operations may be performed by analog circuitry or by a microprocessor executing software that performs the equivalent of the analog operation. Signal lines may be implemented as discrete analog or digital signal lines, as a discrete digital signal line with appropriate signal processing that is able to process separate signals, and/or as elements of a wireless communication system. 
         [0015]    When processes are represented or implied in the block diagrams, the steps may be performed by one element or a plurality of elements. The steps may be performed together or at different times. The elements that perform the activities may be physically the same or proximate one another, or may be physically separate. One element may perform the actions of more than one block. Audio signals may be encoded or not, and may be transmitted in either digital or analog form. Conventional audio signal processing equipment and operations are in some cases omitted from the drawings. 
         [0016]      FIG. 1  illustrates a non-limiting example of an audio system  60  and a portable computer device  62  that can be used in the present disclosure. Audio system  60  has audio signal source  10 , audio signal processing circuitry  12 , and one or more loudspeakers  14 . Audio system  60  also includes controller  72  and transceiver  70  that is adapted for bilateral wireless communication with portable computer device  62 . In one non-limiting example audio system  60  is a stand-alone, portable wireless speaker package such as the Bose® SoundLink®, available from Bose Corporation, Framingham, Mass. A portable wireless speaker package can use various audio signal sources: for example it can receive audio signals from portable computer device  62  or from an internet radio station, as just two non-limiting examples. 
         [0017]    In this non-limiting example, portable computer device  62  has microphone  16 , acoustic measuring circuitry  19 , controller  26 , and equalization calculation circuitry  18 . Portable computer device  62  also includes transceiver  74  that accomplishes the communication to and from audio system  60 , as depicted by dashed line  90 . In one non-limiting example portable computer device  62  is a smartphone with an appropriate software application that is able to command the smartphone to achieve the remote device functionality described herein. One non-limiting example of a smartphone that can be used is the iPhone®, available from Apple Inc., Cupertino, Calif. Many smartphones have a built-in microphone that can be used as microphone  16 . If not, a separate microphone can be used and properly coupled to device  62 , e.g., via an analog or digital connector. Many smartphones also have processing capability that can be used to accomplish circuitry  19 , controller  26 , and circuitry  18 . If device  62  is used to control or communicate with system  60  in other fashions (e.g., if device  62  separately operates as a remote control for system  60 , or if device  62  provides audio signals that are played by system  60 ), controller  26  can output or input directly from transceiver  74 . Many smartphones also include wireless transmit and receive capabilities (e.g., using WiFi, Bluetooth, radio frequency (RF), and/or infrared wireless communications capabilities). Bi-directional wireless communication between audio system  60  and portable computer device  62  can be accomplished by any now-known or later-developed wireless communication technology. The communication can be direct between system  60  and device  62 , or it can be indirect such as via a local router or the like, or via the cloud as indicated at  80 . 
         [0018]    One exemplary, non-limiting process for equalizing audio system  60  involves a person moving portable computer device  62  about the room in which audio system  60  is located, while system  60  plays a series of test tones that are then received by device microphone  16 . Instead of test tones, system  60  can play music or pink noise as the test audio that is then received by microphone  16 . The audio signals for music or pink noise can in one non-limiting example come from portable computer device  62  and be transmitted to audio system  60  via wifi and a local router. The frequency responses corresponding to the received sounds are then calculated by controller  26  running an appropriate software program of the type known in the art for calculating frequency responses, and/or information that is based on frequency responses and that can be used by audio system  60  to achieve a desired frequency response from loudspeaker(s)  14 . Such information that is based on the calculated frequency responses can include audio parameters such as filter coefficients, gains and/or delays that can be used by audio system  60  to produce properly equalized sound from loudspeaker(s)  14 . As an alternative to computing the audio parameters by device  62 , the computation can be done by a remote computing device as indicated by cloud  80 . The computed audio parameters, and/or the information that is based on frequency responses, are then sent to audio system  60  directly from device  62  (via transceiver  74 ) or indirectly, e.g., via wifi/local router or cloud  80 . Audio system  60  saves this information in memory associated with controller  72 . This information is then used by audio system  60  to equalize audio it plays via loudspeaker(s)  14 . 
         [0019]    High quality equalization requires a consistent or known time between generation of the equalization test sound excitation signals by the audio signal source, and receipt of the resulting test sounds by microphone  16 . There can be situations in which this timing can be inconsistent. For example, when system  60  and device  62  wirelessly communicate via WiFi and a local router there can be unknown radio delays (e.g., the delay can depend on the state of the network quality at the moment, and the amount of buffering). Also, the acoustic delay depends on the distance between audio system  60  and personal computer device  62 , which is unknown and variable. In such situations the calculation of audio parameters that are used to equalize audio system  60  can be improved by correlating the audio signal source with the microphone signals so as to determine the time delay, and then taking the time delay into account when the transfer functions (frequency responses) are calculated. Determining a time delay using correlation between two series is a technique known in the art. Using the determined time delay in the frequency response calculation is also a technique known in the art. Correlation can be accomplished by controller  26 . The correlation results can then be used by controller  26  in the calculation of the audio parameters. 
         [0020]      FIG. 2  illustrates a second non-limiting example of an audio system  90  and a smartphone  100  that can be used in the present disclosure. Some details of audio system  90  and smartphone  100  that were disclosed relative to audio system  60  and portable computer device  62 ,  FIG. 1 , are not discussed in detail relative to  FIG. 2 , so as to simplify the drawings and description. Audio system  90  has audio signal source  92 , controller  94 , loudspeaker(s)  96 , transceiver  99  and infrared (IR) receiver  98 . In one non-limiting example audio system  90  is a stand-alone, portable wireless speaker package such as the Bose® SoundLink®, available from Bose Corporation, Framingham, Mass. Smartphone  100  has digital and/or analog input/output interface  106  (e.g., an audio jack and/or a USB port), controller  104 , transceiver  108  and user interface (UI)  102 . One non-limiting example of a smartphone that can be used is the iPhone®, available from Apple Inc., Cupertino, Calif., loaded with an appropriate software application that is able to command the smartphone to achieve the functionality described herein. 
         [0021]    Dongle  110  is a separate device that is configured to be functionally coupled to smartphone  100  via the smartphone input/output  106 . Dongle output signals that are received by smartphone  100  can be analog or digital. Non-limiting examples of electrical interconnection of dongle  110  and smartphone  100  include analog connection via a plug that fits into an analog input jack of smartphone  100 , and digital input via a digital connector that fits into a USB port or other digital port of smartphone  100 . Dongle  110  can have microphone  112  that functions as a receiver of test tones from audio system  90 , although if smartphone  100  includes a microphone then dongle  110  does not need microphone  112 . Dongle  110  includes an IR transmitter  114  that is configured to translate smartphone output signals into IR signals that arc broadcast into the room and received by audio system IR receiver  98 . Alternatively, or additionally, audio system  90  and smartphone  100  can wirelessly communicate as described above relative to  FIG. 1  and as illustrated by transceiver  99 , transceiver  108 , wireless communication  122 , and cloud  120 . Smartphone output signals that are translated and broadcast as IR by dongle  110  can include but are not limited to audio parameters or information that can be used to achieve a desired frequency response from audio system  90 , calculated by smartphone  100  or in the cloud, as described above. Smartphone output signals that are sent as IR signals by dongle  110  can also include audio system control signals such as volume control, internet radio station selection or audio track selection when smartphone  100  is adapted to function as an audio system remote control and dongle  110  adds to the remote control function an IR transmit function that allows audio system control via its IR receiver  98 . 
         [0022]    As part of the communication scheme between audio system  90  and smartphone  100 , audio system  90  can provide to smartphone  100  feedback concerning the transmitted IR signals it has received. This is one way to ensure that the correct information has been transmitted by the smartphone and received by the audio system. The feedback can in one non-limiting example be accomplished via loudspeaker  96 . For example, a unique tone or series of tones could be played by audio system  90  to indicate receipt of audio parameters from smartphone  100 . Or, acknowledgement information could be sent via transceiver  99 . In one example, the smartphone could continue to transmit calculated audio parameters until their receipt was acknowledged by audio system  90  in some manner. 
         [0023]    The systems shown in  FIGS. 1 and 2  have components and functionality that can be used in manners other than as depicted in the drawings. For example, the IR communication functionality of  FIG. 2  can be used in the  FIG. 1  system. Also, smartphone  100 ,  FIG. 2 , could be replaced by another device (whether portable or not) that was adapted to receive test tones and transmit IR and/or other wireless communications signals. One example of such a device is a second audio system, for example a speaker package (wireless, or not, and portable, or not) that has existing IR transmit capabilities that can be used as IR transmitter  114  and an existing microphone that can be used as microphone  112 . In this case, there would be no need for a dongle since the speaker package itself would already include all of the functionality of dongle  110 . 
         [0024]    Embodiments of the systems and methods described above comprise computer components and computer-implemented steps that will be apparent to those skilled in the art. For example, it should be understood by one of skill in the art that the computer-implemented steps may be stored as computer-executable instructions on a computer-readable medium such as, for example, floppy disks, hard disks, optical disks, Flash ROMS, nonvolatile ROM, and RAM. Furthermore, it should be understood by one of skill in the art that the computer-executable instructions may be executed on a variety of processors such as, for example, microprocessors, digital signal processors, gate arrays, etc. For ease of exposition, not every step or element of the systems and methods described above is described herein as part of a computer system, but those skilled in the art will recognize that each step or element may have a corresponding computer system or software component. Such computer system and/or software components are therefore enabled by describing their corresponding steps or elements (that is, their functionality), and are within the scope of the disclosure. 
         [0025]    A number of implementations have been described. Nevertheless, it will be understood that additional modifications may be made without departing from the scope of the inventive concepts described herein, and, accordingly, other embodiments are within the scope of the following claims.