Method and system for monitoring and reporting speaker health

Abstract

A method is provided, comprising: defining a plurality of frequency bins; during a training phase, sending test signals at different amplitude levels to one or more speakers and collecting the resulting test voltage (V) and current (I) points for the different amplitude levels and for each frequency bin; for each frequency bin, applying a linear regression algorithm to the collected test voltage and current points for the different amplitudes to obtain a reference electrical impedance of the one or more speakers; during a monitoring phase subsequent to the training phase, sending an audio signal to the one or more speakers and collecting the resulting new voltage and current points to obtain an operating electrical impedance of the one or more speakers for each frequency bin; determining a deviation between the operating electrical impedance and the reference electrical impedance; and reporting the deviation to a user if the deviation exceeds a defined tolerance.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Patent Application No. 62 / 886,910 filed on August 14, 2019 and European Patent Application No. 19210577.3 filed on November 21, 2019, both of which are incorporated herein by reference. Technical Field

[0003] One or more embodiments relate generally to speaker systems and, more particularly, to monitoring and reporting speaker health. Background Art

[0004] The use of high-power amplifiers and new immersive audio formats (such as Dolby ) generates many audio channels for playback through a large number of speakers in a massive array. Such arrays typically extend existing surround sound formats by adding multiple speakers per group (e.g., front / rear, front left / front right, rear left / rear right, etc.). For immersive audio playback, overhead height speakers may also be provided.

[0005] New cinema or large-scale audio systems feature multiple output channels to drive multiple speakers in each surround channel. Speaker arrays of 32 to 64 or more speakers are not uncommon, and each speaker can be a multi-driver unit with a low-frequency speaker (woofer), a midrange driver, and a tweeter, all of which have a large number of physical and / or wireless connections. In a wide range of audio playback environments, maintaining sound quality after initial installation can be difficult due to degradation or failure of sensitive components (e.g., tweeter voice coils) and simple aging of the equipment. During use, many different electrical or electromechanical problems may occur, such as driver damage, poor physical connections, wireless signal interference, etc. In large-scale installations such as cinemas, correcting such problems often requires a service technician to individually diagnose each speaker to find the specific problem and repair or replace it in a typically difficult operating environment (e.g., overhead or high wall-mounted speakers). In many cases, diagnostic and repair activities may be postponed until the sound quality has significantly degraded, resulting in listeners potentially experiencing less-than-expected audio quality.

[0006] The subject matter discussed in the background section should not be considered to be prior art simply because it is mentioned in the background section. Similarly, it should not be considered that the problems mentioned in the background section or associated with the subject matter of the background section have been previously identified in the prior art. The subject matter in the background section merely represents different approaches, which themselves may also be inventions. Summary of the invention

[0007] The speaker health monitoring and reporting component and method perform current and voltage (VI) measurements on the speaker when configured to operate in a reference mode to obtain a reference electrical impedance of the speaker. Then, the VI measurement is performed on the speaker when the speaker is operated in a normal playback mode to obtain an operating electrical impedance. The operating electrical impedance is compared with the reference electrical impedance to determine the deviation between the operating electrical impedance and the reference electrical impedance, and any deviation exceeding a defined tolerance is reported to maintenance personnel so that the electrical or electromechanical fault of the speaker can be repaired.

[0008] Embodiments include methods and systems that continuously monitor the health of loudspeakers and loudspeaker components compared to an initial baseline condition of a new installation, detect out-of-tolerance conditions, and provide detailed actionable reports to a technician, system operator / owner, or other appropriate personnel.

[0009] Embodiments further relate to methods of making and using such a speaker health monitoring and condition reporting assembly for an audio playback system. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In the following figures, the same reference numerals are used to refer to the same elements. Although the following figures depict various examples, one or more implementations are not limited to the examples depicted in the figures.

[0011] Figure 1 An audio playback environment with a large number of speakers driven by a multi-channel cinema processor and high power amplifiers is shown in accordance with some embodiments.

[0012] Figure 2 A theater environment is shown with a surround sound speaker array powered by a multi-channel power amplifier in accordance with some embodiments.

[0013] Figure 3 is a block diagram illustrating the main functional components of a multi-channel amplifier according to some embodiments.

[0014] Figure 4 is a flow chart illustrating a general method of calibrating, monitoring, and reporting speaker health in accordance with some embodiments.

[0015] Figure 5 A multi-channel amplifier operating in a rendering environment and having a speaker health monitoring component is shown in accordance with some embodiments.

[0016] Figure 6 Certain functional components of a speaker health monitoring process or component are shown according to some embodiments.

[0017] Fig. 7AStages of health monitoring functionality and corresponding data sets are shown according to some embodiments.

[0018] Figure 7B A method for Fig. 7A The frequency bins of the system are datasets.

[0019] Figure 7C Example histograms for V, I data containers are shown in accordance with some embodiments.

[0020] Figure 8 is a flow chart illustrating a health monitoring method using the system of claim 7 according to an embodiment.

[0021] Fig. 9 The generation of per-channel gain levels based on certain amplifier operating characteristics is shown in accordance with some embodiments. DETAILED DESCRIPTION

[0022] Systems and methods are described for a speaker health monitoring and reporting system for use in a speaker installation. The system monitors certain electrical and electromechanical characteristics of various speaker components, including the condition of the individual drivers within the speaker and the physical connections to the speaker. It establishes baseline operating characteristics, continuously monitors the speakers during normal operation, and reports any deviations between the operating characteristics and the baseline conditions to facilitate efficient repair of any system components. For example, the system can address problems associated with having a large number of speakers in a large installation (which can create a high burden for proper speaker maintenance) by continuously monitoring the electrical / electromechanical health of the speakers, identifying specific problems, and providing actionable reports so that the appropriate personnel can efficiently make the necessary repairs.

[0023] Aspects of one or more embodiments described herein can be implemented in an audio or audio-visual (AV) system that processes source audio information in a mixing, rendering, and playback system that includes one or more computers or processing devices that execute software instructions. Any of the embodiments described can be used alone or in any combination together with each other. Although various embodiments may be stimulated by various defects of current and known solutions (which may be discussed in the specification), these embodiments do not necessarily solve any one of these defects. Different embodiments can solve different defects, and some defects may only be partially solved.

[0024] For the purposes of this specification, the following terms have associated meanings: the term "channel" refers to an audio signal plus metadata (where the position is encoded as a channel identifier, such as left front or right upper surround); "channel-based audio" is audio formatted for playback through a set of predefined speaker zones, with associated nominal positions, such as 5.1, 7.1, etc. (i.e., the set of channels just defined); the term "object" refers to one or more audio channels with a parametric source description, such as an apparent source. source) position (e.g., 3D coordinates), apparent source width, etc.; “object-based audio” refers to the collection of objects just defined; and “immersive audio” (alternately, “spatial audio” or “adaptive audio”) refers to channel- and object-based or object-based audio signals plus metadata for rendering the audio signals based on a playback environment that uses an audio stream plus metadata (wherein the position is encoded as a 3D position in space); “listening environment” refers to any open, partially enclosed, or fully enclosed area, such as a room that can be used to play audio content alone or in conjunction with video or other content, and can be implemented in homes, cinemas, theaters, auditoriums, studios, game consoles, etc.

[0025] The term "speaker" or "loudspeaker" refers to an audio playback speaker having a cabinet containing one or more drivers, where the term "driver" refers to an individual audio transducer that converts electrical audio signals into sound waves, and can be implemented as a cone, horn, or planar driver, and can be a full-range driver or configured to play a specific frequency range, such as a tweeter, mid-range driver, woofer, subwoofer, etc.

[0026] Figure 1 An audio playback environment using a large number of speakers driven by a multi-channel cinema processor and high power amplifiers is shown in accordance with some embodiments. Figure 1 An example cinema environment is shown with a surround sound speaker array powered by a cinema processor and power supply. Figure 1 As shown, theater 102 includes a screen 101 that faces a plurality of seats 110 in a viewing / listening area at one end of the room. A plurality of speakers 105 are arranged at the front of the theater room, while speakers 104 are at the rear of the theater room. These speakers play front and rear surround signals. One set of speakers 102a and 103a provides right side sound that can be divided into right front 102a and right rear 103a signals, while another set of speakers 102b and 103b provides left front and left rear signals. In an immersive audio environment, overhead speakers that project downward from the ceiling may be provided. For Figure 1, such overhead speakers are shown in an array of two rows 106a and 106b. Overhead sound may also be provided (at least in part) by one or more side or floor mounted speakers that project sound upward so that the sound is reflected from the ceiling into the listening area 110.

[0027] like Figure 1 As shown, a relatively large number of speakers can be provided to provide multiple individual speakers for each surround sound channel. The number of speakers depends on the size of the theater (or auditorium), the nature of the audio content, the power and output configuration of one or more power amplifiers, and other similar parameters. Figure 1 The theater environment and speaker configuration are for illustration purposes only, and any other actual configuration and number of speakers may be used.

[0028] In a cinema environment, loudspeakers often handle high signal levels and are called upon to reproduce complex audio content, and problems associated with loudspeakers may occasionally occur. Figure 1 As can be seen, the large number of speakers (each of which may include more than two drivers) and their problematic placement or mounting (e.g., on a ceiling or behind a screen or wall) presents some challenges for easily diagnosing and repairing any problems that may arise. Since most speaker problems require physical repairs, such as replacing a driver, repairing a connection, or replacing the speaker itself, such service work is often time consuming and expensive. It may be necessary to individually test or inspect an entire array or sub-array of speakers, speaker by speaker, to identify problems that may be caused by a single speaker in the array. In a frequently used audio environment, such as a movie theater, concert hall, etc., such an operation may require closing the venue for a considerable period of time.

[0029] An embodiment of a speaker system such as Figure 1 As shown, a speaker health component and process are included that facilitates detection and identification of problematic speakers. This enables a technician to quickly locate problematic speakers and identify specific issues to apply appropriate repairs without having to perform extensive system checks and speaker diagnostics.

[0030] Figure 1 A typical theater system typically includes a sound processor and one or more power amplifiers to drive all of the speakers in the system. In a typical implementation, the processor and / or amplifier may be provided as an integral or separate rack-mounted component installed in the A / V room of a theater or auditorium control room. Such components may be provided in a control center 150, which is provided in a control room or similar location in the room. Figure 1 As shown, the control center also includes a speaker health monitoring and reporting component 152 .

[0031] Figure 2 A theater environment with a surround sound speaker array powered by a multi-channel power amplifier is shown in accordance with some embodiments. Figure 2 As shown, a theater or similar audio / video (A / V) listening environment 210 has an array of speakers 208 and 214 placed around a screen 212, and the listening environment is in any suitable surround sound arrangement (e.g., 5.1, 7.1, 9.1, etc.). Audio content is provided by a projector 202 through a sound processor 204 and then provided to a multi-channel amplifier 206. The multi-channel amplifier 206 drives the speakers 208 and 214 through separate speaker feeds. Figure 2 Each speaker element 208 shown may represent multiple individual speakers, such that the total number of speakers is more similar to Figure 1 The situation shown in .

[0032] for Figure 2 In an embodiment, amplifier 206 may represent a multi-amplifier rack-mount system with multiple amplifier cards that are inserted into a rack, where each amplifier drives a certain number of channels (e.g., each amplifier drives 8 channels, or similar). The amplifier may also be embodied as a single integral amplifier with multiple channel outputs. Alternatively, it may be implemented as two or more amplifiers connected together in a serial or daisy-chain manner to form an amplifier system with a master / slave configuration. In one embodiment, all or most of the speakers may be passive speakers, thus requiring a relatively high power output from the amplifier. Alternatively, at least some of the speakers may be active (powered), thus requiring lower power from the amplifier. The amplifier configuration may be customized so that different amplifiers drive different interleaved speaker groups, and so on. In one embodiment, the number of channels is increased by each individual amplifier, such as 2x24 for a total of 48 channels for one or two amplifiers in the amplifier system. Alternatively, the master / slave amplifiers may be configured so that the number of channels remains unchanged, but the power overhead of each channel is increased by additional amplifiers, or any other similar combination of channels and / or power overhead is increased. Depending on the speaker array configuration and the theater environment, any number of different amplifier configurations are possible.

[0033] For embodiments where analog amplifiers may be used to power the speakers, such as older theater installations, the amplifier system may be coupled to the analog amplifiers via a digital audio converter (DAC) to convert the digital signals from the renderer or sound processor 204 into the analog signals required by the analog amplifiers.

[0034] Figure 3 is a block diagram showing the main functional components of a multi-channel amplifier according to some embodiments. Figure 3In the system, the audio signal from the renderer 302 is amplified in the amplifier 304 and transmitted to the speaker array 312.

[0035] In one embodiment, Figure 3 The speakers 312 are configured and placed to play immersive audio content, where the audio signals presented to the listener originate from the front and surrounding of the listening position in the horizontal plane (main speakers) and the overhead plane (high speakers). A complete speaker system layout may include: front speakers (e.g., left, center, right, and optional left center right center, left screen, right screen, left wide, and right wide), surround speakers (e.g., left surround, right surround, and optional left surround 1, right surround 1, left surround 2, right surround 2), surround back speakers (e.g., left rear surround, right rear surround, center surround, and optional left rear surround 1, right rear surround 1, left rear surround 2, right rear surround 2, left center surround, right center surround), height speakers (e.g., left front height, right front height, left upper front, right upper front, left upper center, right upper center, left upper rear, right upper rear, left rear height, right rear height), and a subwoofer speaker. This represents one example of a speaker configuration, and other configurations are also possible.

[0036] Component 302 generally represents an audio component that is often referred to as a "renderer." Such a renderer may include or be coupled to a codec that receives audio signals from a source, decodes the signals and transmits them to an output stage that generates speaker feeds to be transmitted to individual speakers in the room. In an immersive audio system, channels are sent directly to their associated speakers or down-mixed to an existing set of speakers, and audio objects are rendered by a decoder in a flexible manner. Thus, rendering functionality may include aspects of audio decoding, and unless otherwise specified, the terms "renderer" and "decoder" may both be used to refer to the immersive audio renderer 302, such as Figure 3 In general, the term "renderer" refers to a component that delivers a speaker feed to a speaker, which may or may not have been decoded upstream. In one embodiment, Figure 3 The AVR or renderer / decoder 305 comprises an audio / video receiver for a home entertainment environment. An AVR typically performs multiple functions. First, it provides a connection point for multiple source devices, and the AVR is responsible for switching between inputs. Second, it performs audio decoding and processing (e.g., surround sound processing, Dolby Pro Logic TM Processing, Dolby Digital TM Processing, Dolby TrueHD TM It can also provide amplification or pre-amplification for loudspeakers. Figure 3In the embodiment of FIG. 3 , amplification for driving speaker 312 is provided by amplifier 304 .

[0037] In one embodiment, amplifier 302 is a multi-channel class-D amplifier that includes the main functional components of a power sharing controller 306, a power subsystem 308, and a fault detector 310. A speaker health monitoring and reporting component 314 may be provided as part of the amplifier or as a separate component that provides certain operating and environmental condition data to the amplifier 314.

[0038] In one embodiment, amplifier 304 provides power sharing or power steering of a common power subsystem 308 across all channels of a multi-channel speaker output stage. In an example configuration, up to 24 channels can be supported, but other possible embodiments are not limited thereto. The power subsystem (or "power stage") 308 can utilize two redundant power supplies (e.g., in series or parallel), but other single or multiple power supply configurations are also possible. The power supplies are redundant, and the failure of one power supply will cause the other power supplies to activate and provide power to the amplifier. A fault detector 310 monitors the status of the power subsystem 308 and detects the health of the power supplies. It is configured to shut down the failed power supply when an error is detected and use the remaining power supply to power the unit.

[0039] In one embodiment, the speaker health monitoring and reporting component 314 continuously (or periodically) samples the audio performance of the theater or cinema 102 on a prescribed basis and detects and predicts speaker problems, such as performance degradation, shorted or open drivers, or the introduction of friction / hum in the audio. The amplifier is configured to send a report through a GUI or signal component to indicate a speaker fault condition. Alternatively, it can be configured to shut down the channel and notify the renderer 302 to re-render the content, mapping out the failed speaker and using other speakers to compensate for the failed or missing speaker. It can also be configured to detect non-speaker performance issues in fixtures or tiles in the theater, such as friction and hum, to prevent unnecessary inspections of speakers. All of this information can be provided by re-rendering or can be reported to maintenance personnel.

[0040] like Figure 3 As shown, amplifier 304 includes a speaker health monitoring and reporting component 314 that monitors certain electrical and electromechanical characteristics of various speaker components, including the condition of the various drivers within the speaker and the physical connections to the speaker. It establishes baseline operating characteristics, such as basic speaker impedance, continuously monitors the speakers during normal operation, and reports any deviations between the operating characteristics (e.g., operating speaker impedance) and the baseline condition to facilitate repair of any speaker.

[0041] In general, the primary characteristic of a speaker driver is its electrical impedance, Z, as a function of frequency (which can be plotted as an impedance curve graph). With regard to speaker health monitoring, voltage (Vx) and current (Ix) parameters can be used to provide the frequency response of the speaker (using Fourier transforms) and can help determine the health of individual drivers. This is done by measuring the impedance (Z=V / I) and verifying that it matches the expected curve for the speaker. The system can flag a speaker as broken or damaged based on any deviation from this expected curve, facilitating efficient repairs during operation, shutting down the speaker, or causing re-rendering of the audio to accommodate speaker failures.

[0042] In most cases, this simple V / I method can only detect simple open and short circuit conditions in the speaker. Therefore, it may not be able to detect more complex or subtle problems, such as a bad tweeter in a two-way speaker. This is because an open circuit tweeter downstream of the passive crossover filter will appear as a small change in the impedance (I) curve, which may not be large enough to trigger an "open circuit" failure at the amplifier output. This condition may be due to the fact that the impedance only changes at higher frequencies. Other similar electrical or electromechanical failure conditions may also be slip-detectable with standard V / I measurements. In one embodiment, the speaker health monitoring and reporting component 314 includes a speaker failure detection process that detects changes in the impedance curve of each speaker.

[0043] Figure 4 is a flow chart illustrating a general method for calibrating, monitoring, and reporting loudspeaker health using impedance curve comparison according to some embodiments. Figure 4 The method begins by measuring a new loudspeaker installation in a theater (or similar venue) or measuring a known good installation (i.e., one in which all loudspeaker components are known to operate as designed or expected), step 402. In one embodiment, this is accomplished by playing a test signal (e.g., pink noise) through the loudspeakers and taking V, I measurements of each loudspeaker using one or more Hall Effect sensors in the amplifier. Current and voltage measurements are taken for each channel at different amplitude levels to provide a comprehensive V, I curve for each channel. This establishes a known good baseline measurement to which the loudspeakers in actual operation will be compared.

[0044] At step 404, the loudspeaker is continuously monitored to measure the same V, I characteristics, whether using test tones or actual dramatic content. The frequency of the monitoring process can be set based on system configuration constraints and requirements. In one embodiment, a constant playback analysis system can be used. Alternatively, the system can be configured to monitor the loudspeaker only under certain conditions, for example, not during known non-operation periods, or not during playback of irrelevant or uninteresting signals; or on a longer period basis (e.g., once an hour, once a day, etc.).

[0045] The operating characteristics are compared to the baseline by directly comparing their respective V, I curves at step 406. Any deviation in operation from the baseline data may indicate a fault condition caused by a speaker or driver failure, e.g., due to an open or shorted driver, a bad connection, etc. The deviation may be defined by a tolerance assigned to the baseline curve, e.g., a minimum percentage deviation within a specified range based on the frequency, amplitude, or other characteristic of the audio signal.

[0046] At step 408, any deviations beyond defined tolerances from the baseline are reported to appropriate personnel via a reporting mechanism. Such a reporting mechanism may be a visual indication, such as via an amplifier front panel (e.g., a warning light or message), a web-based GUI; a standard network message, such as SNMP (Simple Network Management Protocol); or a dedicated message, such as a Dolby Cinema Processor message. The alert or message is intended to flag and identify the problematic speaker or speakers so that appropriate personnel (e.g., an installer or technician) can take action to resolve the issue without excessive testing or diagnosis of the speakers (some of which may be difficult to access).

[0047] In one embodiment, the operating characteristics may be sent to a cinema processor or renderer to allow the system to re-render the audio signal to bypass the problematic speaker or otherwise compensate for the missing or damaged speaker output (step 410).

[0048] The V, I characteristics of a speaker can represent the electrical impedance of the speaker. Figure 4 The speaker health monitoring and reporting component performs current and voltage (VI) measurements on the speaker when the speaker is configured to operate in a reference mode to obtain a reference electrical impedance (or "baseline characteristic") of the speaker, and then performs VI measurements on the speaker when the speaker is operated in a normal playback mode to obtain an operating electrical impedance. The operating electrical impedance is compared with the reference electrical impedance to determine the deviation between the operating electrical impedance and the reference electrical impedance, and any deviation exceeding a defined tolerance is reported to maintenance personnel so that the electrical or electromechanical fault of the speaker can be repaired.

[0049] Figure 4 At least a portion of the method of may be implemented as software instructions executed by certain processing components in or associated with the amplifier 206 or the sound processor 204. Alternatively, they may be performed by hardware components in the amplifier 304. Such a system may be configured to play certain advanced audio signals, such as immersive or object-based audio. Figure 5A multi-channel amplifier operating in a rendering environment and having a speaker health monitoring component according to some embodiments is shown. As described above, in one embodiment, the amplifier 504 is configured to work with a compatible renderer 506 that provides audio signals on the same number of channels (speaker feeds) output by the amplifier. Such a renderer can be a Dolby Atmos Cinema Processor CP850, or a similar sound processor. Such a renderer plays traditional 5.1 and 7.1 surround sound formats as well as immersive audio content (e.g., Dolby Atmos, which includes audio objects and bed (channel-based audio)). In general, audio objects can be considered to be groups of sound elements that can be perceived as emanating from one or more specific physical locations in a listening environment. Such objects can be static (stationary) or dynamic (moving).

[0050] In such a system, audio objects are controlled by metadata that defines the location of the sound at a given point in time, along with other features. When the objects are played, they are rendered according to the positional metadata using the existing speakers, rather than having to output these objects to predefined channels. In an immersive audio decoder, channels are sent directly to their associated speakers or downmixed to an existing set of speakers, and audio objects are rendered by the decoder in a flexible way. A parametric source description associated with each object, such as a position track in 3D space, is taken as input along with the number and position of the speakers connected to the decoder. The renderer uses certain algorithms to distribute the audio associated with each object across the attached set of speakers. Therefore, the authoring space for each object is intended to be best rendered on the specific speaker configuration present in the listening environment.

[0051] for Figure 5 In an embodiment of the invention, the renderer 506 includes an immersive audio rendering module and channel gain control to transmit appropriate digital audio signals to the amplifier 504. The metadata processor processes the corresponding parameter position / location / trajectory data of the audio objects to generate N-channel speaker feeds for the amplifier 504. The amplifier 504 includes a common power subsystem that provides power to all channels of the speaker array 508 and sets per-channel gain values ​​based on audio content and input from monitoring components that monitor power, environment, and operating conditions. The amplifier 504 may also include a closed-loop synchronization circuit to ensure that the channels are clocked and switched simultaneously to mitigate noise, beats, and other distortions.

[0052] Assume that the number of speakers in the speaker array 508 is relatively high, for example, 16 to 32 or more speakers, at least some of which may be mounted in challenging locations, such as high wall or ceiling mounts. In one embodiment, the amplifier includes or is coupled to a health monitoring unit 510 that monitors certain operational and health characteristics of the speakers and provides feedback to the renderer 506 or a user via a GUI or similar interface 511. For the illustrated embodiment, the speaker health component 510 includes certain functional subcomponents of a calibrator 511, a detector 512, and a reporter 513, which perform Figure 4 The functionality shown in the method.

[0053] Figure 6 The functional components of the speaker health monitoring process or component 510 are shown in more detail according to some embodiments. In one embodiment, the health monitoring process or health monitoring component 601 performs multiple processes including a calibration component 602, a test data processor 604, a monitoring component 606, and a reporting component 608.

[0054] like Figure 6 As shown, the speaker health monitoring and reporting component 601 implements a calibration component or function 602. The component performs a calibration process on a known set of healthy speakers using a test signal (e.g., a pink noise test pattern or similar test signal). This represents the training phase of the monitoring process. During the training phase, multiple V and I points are collected from the feedback of the test signal and stored in a memory. A plurality (N) of frequency bins (e.g., 29) are selected to provide V and I data. The pink noise test pattern is selected because it is time-invariant. Alternatively, any other custom test signal may be used depending on the system configuration.

[0055] Figure 7B A frequency bin data set according to some embodiments is shown. Data set table 710 shows various V, I data points for each bin, denoted as bin 0 to bin N. Any suitable number of bins may be used, and a different number of V, I values ​​may be provided for each bin, as shown.

[0056] In one embodiment, the frequency bins are arranged in steps of 1 / 3 octave. The real part of the impedance Z measured in steps of 1 / 3 octave is stored in bins at different levels. In one embodiment, the level is swept over a range of -40 dB to 0 dB and falls back to -40 dB at certain level increments. Thus, these bins store the impedance versus frequency for each channel at various levels. These bins may be arranged according to known standards, such as the 13 bins of the SMPTE standard, or any other suitable arrangement.

[0057] During training mode, the loudspeakers in the auditorium are scanned in a configurable group pattern for the following reasons: 1) installers are not affected by high levels of pink noise from multiple drivers, 2) maximum power draw during testing can be managed, and 3) optimal readings from the Hall Effect sensors are ensured by minimizing crosstalk from high energy levels on adjacent channels.

[0058] In one embodiment, the test audio signal is swept up and down within a specified range. Since the impedance curve of a loudspeaker may change with temperature, the horizontal up and down sweep will excite (heat) the voice coil and indicate or allow for any thermal effects. In this way, the system can adapt to thermal effects to reduce the likelihood of false positives during the comparison step.

[0059] After a sufficient amount of data has been collected, the data points are processed using a test data processor function 604. In one embodiment, the test data is processed using a linear regression algorithm to fit a believed healthy loudspeaker curve that was acquired during the baseline measurement step 402.

[0060] Once a healthy or optimal speaker curve is obtained, the speaker health process enters the monitoring phase of the monitoring component 606, in which all new points during actual speaker operation are collected and compared with the healthy speaker curve to detect speaker failures or problems and report them to the user through a GUI or similar reporting mechanism.

[0061] Fig. 7A 1 shows the stages of health monitoring functionality and corresponding data sets according to some embodiments. Fig. 7A As shown, the training component 702 receives a user command to start or restart the training function. This inputs a pink noise test to each speaker. The output of the training phase is a V, I data set 701, which has various V, I points for each of a plurality of frequency bins. The data points are processed using a linear regression function 704, which outputs a healthy fit curve 703 on the VI graph. The monitoring phase 706 checks the new V, I points against the curve and outputs a fault condition if any point does not meet, or an OK signal if all points meet.

[0062] for Fig. 7A In the embodiment of the present invention, the data set 701 includes a database of columns represented by container 0, container 1, container 2, container 3, etc. until container N, each container having different V and I values. Figure 7B . The healthy fit curve 703 is a graph of V, I values ​​with a horizontal V axis and a vertical I axis. Different data sets and fit curves other than those explicitly shown may also be used.

[0063] In one embodiment, a histogram of V,I data can be generated for healthy speaker curve data stored in a time series database so that the performance changes since the installation date can be graphically displayed through a GUI. As is known, a histogram is a representation of a probability distribution estimate of numerical data. After the data is divided into containers, such as Figure 7B As shown, the range is divided into a series of intervals, and the number of occurrences within each bin is counted and represented in the chart. Figure 7C 2 shows an example histogram for V, I data containers according to some embodiments. Figure 7C As shown, a histogram 720 is plotted for the VI graph, where the rectangles represent the frequency of V, I values ​​in each bin. A fitted curve 722 represents the general shape of the probability distribution of the entire data set. Figure 7C One example of a probability distribution of V, I data values ​​is shown, and other relative frequency graphs may be used.

[0064] Figure 8 is a flow chart illustrating a health monitoring method for a system using claim 7 according to an embodiment. Process 800 begins at 802, where frequency bins (e.g., 1 / 3 octave bins) are defined for the V, I points. Any practical number of bins spanning a certain number of frequencies may be used. A typical number of bins may be 29, but any other number may be used. The training component sends a test signal to all speakers and collects the resulting V, I points for various amplitude levels and for each frequency bin (804). Depending on the system configuration, this task may take on the order of several minutes for each channel. In a typical embodiment, the training phase for a 32-channel system may take on the order of approximately 20 minutes. In the data processor component, all V, I points collected from the training phase are applied to a least squares error algorithm to determine the corresponding fit curves (806). A fit curve is generated for each frequency bin. This defines a healthy fit curve on the VI curve graph, as Fig. 7AAs shown. Once the healthy fit curve is defined, the monitoring component checks each new V, I point to see if it matches or falls within the fit curve tolerance (808). The amount of change from the actual fit curve defines the system's fault tolerance and can be set by the user as a percentage deviation (e.g., 10%) or similar metric. If a point does not meet the defined tolerance, as determined in decision block 810, the monitoring component reports a loading failure to the user via a GUI or other reporting mechanism (812). Otherwise, it continues to check new V, I points and / or reports an OK status (814). Once a loading failure is reported, the system can wait to receive user action, such as an installer or technician fixing / removing a speaker, etc. to reset the system. Alternatively, the theater processor can be configured to automatically re-render the content in an attempt to compensate for the loading failure (816). During process 800, feedback from the monitoring component can also be provided to the renderer or theater processor.

[0065] refer to Figure 6 For the test signal, the calibration component 602 can be configured to send the same sequence of pink noise as used in training; however, previously collected training data will not be overwritten. The real-time monitoring mode 606 is active during this sequence and will assess the health of each channel selected. This is referred to as the "test mode" mode. The group selection criteria and pink noise levels will exactly match those used during speaker training. The only difference is that the duration of the pink noise test pattern is much shorter than that used during training mode.

[0066] In one embodiment, software-controlled state debouncing can be used in conjunction with the test and fit algorithms, and such a process can have an impact on the reported monitoring states. The system should use the states reported from this layer to evaluate live test conditions rather than accessing the algorithm directly. The debouncing process uses a sliding window of time with unique parameters optimized for each FFT container, which automatically resets after a certain period of time. The window is paused whenever there is no live monitoring data. In other words, the state does not change during long periods of silence. This process is used because some types of drivers may briefly enter a nonlinear state when driven hard, especially large LFE (low-frequency effect) drivers or subwoofers. These may be recorded as false negatives by the monitoring process. To prevent transient conditions from propagating into the software, a debouncing scheme is implemented after the algorithm to mitigate this effect.

[0067] Other filters or process modifiers may also be applied. For example, during field monitoring, if a captured value lies outside the range of a training window (either above or below), the reading will be discarded. The software will wait for the next set of values ​​within the training window of the data before evaluating the field conditions. This means that something with a very small dynamic range may not immediately register a change of state (no matter how drastic). Similar logic applies to raw sensor data based on the capabilities of the instrument in current hardware versions. Metadata is also generated for any "untrained" channels that may be present on a given card, so the same rejection logic can be applied. This logic can also be called "crosstalk rejection." A software debounce layer will be responsible for maintaining the internal state of the algorithm if it should be required.

[0068] Certain functions of the health monitoring process may be managed externally through user controls via the GUI. Others may be controlled internally by system settings. Such controls define certain rules for the operation of the testing and monitoring functions. For example, a rule may be defined such that two adjacent channels in an auditorium will not be trained at the same time. Internally, the system will manage this request in two separate stages, rather than one simultaneous action. The system can accommodate bridged and non-bridged speakers. Any API that exposes 32 channels (or any other number) does not need to care which or what bridge pairs are valid for the configuration. It is sufficient to just set the flag for the first channel that appears in the bridge pair array. Furthermore, even if all 32 channels can be selected, the system will only train in groups of no more than 8 (or any other subset) at a time.

[0069] In one embodiment, the Speaker Health API should provide a time estimate for the training phase. There may be hardware limitations that make it impossible or impractical to measure real-time data below a certain frequency (e.g. 23.44 Hz) or above another frequency (e.g. 8110.24 Hz).

[0070] In one embodiment, the system provides a variable detection threshold for each container. This variable detection threshold exists to reduce the likelihood of reporting erroneous results reading the Hall effect sensor due to the presence of large amounts of energy on adjacent channels. In addition to protecting adjacent channel crosstalk for trained channels, metadata will also be generated for "untrained channels" which will also be fed into the same algorithm used for crosstalk rejection. This software-based crosstalk suppression algorithm can be used in situations where no training data exists on any channel of a given amplifier. If an alternative "Vmax" or "Imax" value is not calculated to replace what would be a normal part of the training data for a given channel, erroneous results in the detection algorithm may result. For amplifiers that contain a mix of trained and untrained channels, metadata is automatically calculated for the untrained channels for use in this crosstalk rejection.

[0071] As described above, known good V, I curves or data are obtained by actual measurements of a newly installed or known good speaker system. The data for the new or known good speaker system includes "baseline" data that represents the speaker system operating under sufficiently satisfactory conditions. In one embodiment, the baseline data can be provided by entering speaker specification data, such as known response curves, VI data, etc. Such data can be entered through an appropriate interface and in a manner suitable to allow direct comparison with the measured V, I data obtained during the monitoring phase. For example, the user can be provided with data for a given speaker manufacturer (e.g., a complete enclosure like QSC or from the Dolby / SLS line), which will be loaded by the user from a web-based user interface or by equivalent means. This data can be loaded into the system in place of running a full training phase using a noise source. The system will then use the provided baseline data instead and enter active monitoring mode directly.

[0072] In one embodiment, V, I data during operation and compared to baseline data can be sent from the amplifier back to the renderer or processor. This allows the signal to be re-rendered in response to any fault conditions of the speaker or driver. For this embodiment, some gain control functionality can be provided to manage and change the gain of each individual channel based on the speaker health and operating conditions monitored by the monitor. Fig. 9 The generation of per-channel gain levels based on certain loudspeaker operating characteristics according to some embodiments is shown. Fig. 9 As shown, the per-channel gain 912 is derived from the output power 910 provided by the amplifier on each of the channels 1-n, where n is any suitable number of channels, such as provided by the renderer. In an example embodiment where the renderer corresponds to a Dolby Atmos Cinema Processor (CP850) or similar renderer, 24 audio channels are output from the renderer and individually amplified by the amplifier 904. The output power 902 is a function of multiple inputs including the input power 902, the audio content 904, and the environmental / operating conditions 906.

[0073] In one embodiment, the gain of each channel may be set or modified based on any speaker failure conditions detected by the speaker failure detector 908. In the event of any failed or failed speaker, speaker cable, output stage, or any other specific channel component, the power of that channel may be attenuated or cut off, and other channels may be boosted accordingly to compensate. Other re-rendering or compensatory measures may include changing the EQ, phase, or other audio characteristics of the audio signal, attenuating or boosting certain surround channels, etc.

[0074] With respect to re-rendering, several possible steps may be taken. One example is the loss of a theatrical center channel. When such a failure is detected, a failure notification is sent to the theater processor to re-render the center channel into the main left / right (L / R) speaker arrays; otherwise, the program is considered "lost" due to the lack of a dialog center channel. The theater processor may handle other types of driver failures differently based on room configuration, active macros, etc. Reference to specific components, e.g., Dolby CP850, is for example only and embodiments are not so limited.

[0075] Unless the context clearly requires otherwise, throughout the specification and claims, the words "comprises," "including," and the like are to be interpreted in an inclusive sense, rather than an exclusive or exhaustive sense. Words using the singular or plural number also include the plural or singular number, respectively. When the word "or" is used to refer to a list of two or more items, the word encompasses all of the following interpretations of the word: any item in the list, all items in the list, and any combination of items in the list.

[0076] Although one or more embodiments have been described by way of example and according to specific embodiments, it should be understood that one or more embodiments are not limited thereto. This description is intended to cover various modifications and similar arrangements that are obvious to those skilled in the art. Therefore, the scope of the appended claims should be based on the broadest interpretation to cover all such modifications and similar arrangements.

[0077] Various aspects of the present invention may be understood from the following exemplary embodiments (EEE):

[0078] EEE 1. A method comprising:

[0079] When the one or more speakers are configured to operate in a reference mode in a listening area, performing current and voltage (VI) measurements on the one or more speakers to obtain a reference electrical impedance for the one or more speakers;

[0080] When the one or more speakers are operated in a normal operation mode of playing audio content in the listening area, performing VI measurement on the one or more speakers to obtain an operating electrical impedance;

[0081] comparing the operating electrical impedance to the reference electrical impedance to determine a deviation between the operating electrical impedance and the reference electrical impedance; and

[0082] If the deviation exceeds a defined tolerance, the deviation is reported to maintenance personnel so that the maintenance personnel can repair the electrical or electromechanical fault of the one or more speakers.

[0083] EEE 2. The method as described in EEE 1 further includes: performing a curve fitting operation using a least square error algorithm to generate a healthy fitting curve for the reference electrical impedance.

[0084] EEE 3. The method of EEE 2, wherein the comparison is performed by comparing the health fit curve with an operational curve generated by the operational electrical impedance. ...

[0085] EEE 4. The method as described in any one of EEE 1 to 3, wherein the step of performing VI measurement includes continuously collecting V, I points for multiple frequency bins of each channel of the loudspeaker at different output levels.

[0086] EEE 5. The method of EEE 4, wherein the different output levels comprise a range of -40 dB to 0 dB and the plurality of frequency bins comprise a step size of 1 / 3 octave. ...

[0087] EEE 6. The method as described in any one of EEE 1 to 5 also includes: playing a pink noise test signal through the speaker and performing V, I measurements on each speaker using one or more Hall effect sensors in an amplifier coupled to the one or more speakers.

[0088] EEE 7. The method of any one of EEE 1 to 6, wherein the reporting step comprises generating a visual message for display via one of an amplifier front panel or a web-based graphical user interface, or a text message for transmission to a computing device via a known or dedicated interface. ...

[0089] EEE 8. The method as described in any one of EEE 1-7 further includes: transmitting the operating electrical impedance to a renderer to facilitate re-rendering the audio content to compensate for the deviation. EEE 8.

[0090] EEE 9. The method as described in any one of EEE 1-8, wherein the reference electrical impedance is input into the system based on speaker characteristics provided by a manufacturer rather than a measured value. EEE 9.

[0091] EEE 10. An apparatus for enabling repair of one or more speakers, comprising:

[0092] a calibration component that generates a test signal to perform current and voltage (VI) measurements on the one or more speakers when the one or more speakers are configured to operate in a reference mode in a listening area to obtain a reference electrical impedance of the one or more speakers;

[0093] a monitor that performs VI measurements on the one or more speakers when the one or more speakers are operating in a normal operating mode of playing audio content in the listening area to obtain an operating electrical impedance;

[0094] a comparator that compares the operating electrical impedance with the reference electrical impedance to determine a deviation between the operating electrical impedance and the reference electrical impedance; and

[0095] interface, and if the deviation exceeds a defined tolerance, reporting the deviation to maintenance personnel to enable the maintenance personnel to repair the electrical or electromechanical fault of the one or more speakers.

[0096] EEE 11. The apparatus of EEE 10, further comprising a data processor that performs a curve fitting operation using a least square error algorithm to generate a health fit curve for the reference electrical impedance.

[0097] EEE 12. The apparatus of any one of EEEs 10 to 11, wherein the calibration component continuously collects V, I points for a plurality of frequency bins for each channel of the loudspeaker at different output levels. EEE 13. The apparatus of any one of EEEs 10 to 11, wherein the calibration component continuously collects V, I points for a plurality of frequency bins for each channel of the loudspeaker at different output levels.

[0098] EEE 13. An apparatus as described in any of EEE 10 to 12, wherein the calibration component plays a pink noise test signal through the speaker and uses one or more Hall effect sensors in an amplifier coupled to the one or more speakers to perform V, I measurements on each speaker, and wherein the different output levels include a range of -40dB to 0dB and the multiple frequency bins include steps of 1 / 3 octave.

[0099] EEE 14. The apparatus of any one of EEEs 10 to 13, wherein the interface generates a signal for visual display via one of an amplifier front panel or a web-based graphical user interface or a text message transmitted to a computing device via a known or dedicated interface. EEE 15. The apparatus of any one of EEEs 10 to 13, wherein the interface generates a signal for visual display via one of an amplifier front panel or a web-based graphical user interface or a text message transmitted to a computing device via a known or dedicated interface.

[0100] EEE 15. A computer program product comprising instructions which, when said program is executed by a computer, cause said computer to perform a method according to any one of EEE 1 to 10. EEE 15.

Claims

1. A method for monitoring a loudspeaker, comprising: Define multiple frequency bins; During a training phase, sending a test signal at different amplitude levels to one or more speakers and collecting the resulting test voltage (V) and current (I) points for the different amplitude levels and for each frequency bin; for each frequency bin, applying a linear regression algorithm to the test voltage and current points collected for different amplitudes to obtain a reference electrical impedance of the one or more loudspeakers; During a monitoring phase following the training phase, audio signals are sent to the one or more speakers and resulting new voltage and current points are collected to obtain an operating electrical impedance of the one or more speakers for each frequency bin, A deviation between the operating electrical impedance and the reference electrical impedance is determined and, if the deviation exceeds a defined tolerance, the deviation is reported to a user.

2. The method according to claim 1, wherein: The plurality of frequency bins are arranged in steps of 1 / 3 octave.

3. The method according to claim 1 or 2, wherein: The different amplitude levels correspond to a range of -40 dB to 0 dB.

4. The method according to claim 1 or 2, wherein: The test signal is a pink noise test signal.

5. The method according to claim 1 or 2, wherein: The defined tolerances are either amplitude or frequency dependent.

6. The method according to claim 1 or 2, wherein: The linear regression algorithm is a least square error algorithm.

7. The method of claim 1 or 2, further comprising re-rendering the audio signal using the operating electrical impedance to compensate for the deviation.

8. An electronic device comprising: a calibration component configured to provide test signals at different amplitude levels to one or more speakers during a training phase and collect the resulting test voltage (V) and current (I) points for the different amplitude levels for a plurality of frequency bins; a test data processor configured to, for each frequency bin, apply a linear regression algorithm to the test voltage and current points collected for the different amplitude levels to obtain a reference electrical impedance of the one or more speakers; as well as a monitoring component configured to collect new voltage and current points for the one or more loudspeakers for each frequency bin during playback of the audio signal during an operation phase subsequent to the training phase to obtain an operating electrical impedance of the one or more loudspeakers and to determine a deviation between the operating electrical impedance and the reference electrical impedance, Wherein, the electronic device is further configured to report the deviation to a user if the deviation exceeds a defined tolerance.

9. The electronic device according to claim 8, wherein: The plurality of frequency bins are arranged in steps of 1 / 3 octave.

10. The electronic device according to claim 8 or 9, wherein: The different amplitude levels correspond to a range of -40 dB to 0 dB.

11. The electronic device according to claim 8 or 9, wherein: The test signal is a pink noise test signal.

12. The electronic device according to claim 8 or 9, wherein: The defined tolerances are either amplitude or frequency dependent.

13. The electronic device according to claim 8 or 9, wherein: The linear regression algorithm is a least square error algorithm.

14. The electronic device according to claim 8 or 9, further configured to provide the operating electrical impedance to a renderer to facilitate re-rendering of the audio signal to compensate for the deviation.

15. A computer program product comprising instructions which, when the program is executed by a computer, cause the computer to perform the method according to any one of claims 1 to 7.

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