System comprising passive headphone and audio controller and method of calibrating passive headphone

Abstract

The invention provides a system comprising a passive headset (101) and an audio controller (102), wherein the passive headset (101) is connected to the audio controller (102). The audio controller (102) is configured to acquire factory calibration data, the data being exclusive to the passive headphone (101) and associated with an identifier of the passive headphone (101), the audio controller (102) being configured to apply the factory calibration data to an electrical signal input to the passive headphone (101).

Description

Technical Field

[0001] This invention relates to a system comprising passive headphones and an audio controller, and a method for calibrating passive headphones. Background Technology

[0002] Passive headphones lack the amplifier and power supply (battery) required to drive the transducers and produce audio output. Therefore, passive headphones need to be connected to an audio controller, which contains the headphone amplifier and power supply components. The audio controller is configured to transmit electrical signals to the passive headphones, which are then output as sound at the headphones. Summary of the Invention

[0003] This invention aims to provide a factory calibration solution for passive headphones.

[0004] This invention is defined by the features of the independent claims. Certain embodiments are defined in the dependent claims.

[0005] According to a first aspect of the invention, a system comprising a passive earphone and an audio controller is provided, wherein the passive earphone is connected to the audio controller. The audio controller is configured to acquire factory calibration data specific to the passive earphone and associated with an identifier of the passive earphone, and is configured to apply the factory calibration data to electrical signals input to the passive earphone.

[0006] The identifier may be specific to the passive earphone, and / or the identifier may be a serial number, component, memory chip, transponder, electronic tag, or radio frequency identification (RFID) tag. The identifier may be attached to the passive earphone, associated with the passive earphone, and / or exist inside the passive earphone or be attached to the passive earphone.

[0007] The audio controller may include an integrated headphone amplifier, the headphones including one or more transducers, wherein the headphone amplifier is configured to amplify electrical signals transmitted to one or more transducers of the passive headphones, and the transducers are configured to reproduce the electrical signals as sound output.

[0008] Factory calibration data is pre-stored in the audio controller paired with the passive headphones and in remote memory. The factory calibration data includes at least one of the following parameters obtained from measurements taken on both sides of the passive headphones: impedance, sensitivity, level, and phase of the acoustic output in response to the electrical input, optionally covering all frequencies. The factory calibration data of the passive headphones applied by the audio controller is configured to adjust the frequency response of the passive headphones.

[0009] The system according to the first aspect may further include a computer configured to connect to an audio controller, wherein the audio controller is configured to receive factory calibration data from the computer, and the computer is configured to access remote memory to receive the factory calibration data stored in the remote memory in response to an identifier provided by the passive headphones. The computer includes at least a processor and a memory containing instructions executable by the processor, and the computer is configured to access the remote memory.

[0010] The identifier of the passive headphones can be automatically received by the audio controller in response to connection to the passive headphones and / or via short-range signaling from the passive headphones. The identifier of the passive headphones can be entered into the computer, received by the computer, received by the computer via short-range signaling, and / or received by the computer from the audio controller.

[0011] When passive headphones are connected to the audio controller via a cable, the audio controller automatically receives information about which end of the audio controller is connected to the passive headphones. This information can also be received via short-range signaling. The audio controller can be connected to the passive headphones via a wired connection, and / or, the audio controller can also be connected to a computer via a wired connection.

[0012] According to a second aspect of the invention, a method for calibrating a passive headphone connected to an audio controller is provided. The method includes: acquiring factory calibration data specific to the passive headphone and associated with an identifier of the passive headphone by the audio controller; and applying the factory calibration data to an electrical signal input to the passive headphone by the audio controller.

[0013] According to a third aspect of the invention, the use of the system comprising a passive headphone and an audio controller as described in the first aspect in audio mixing is provided.

[0014] According to a fourth aspect of the invention, the use of the system comprising a passive headphone and an audio controller as described in the first aspect in studio mixing is provided. Attached Figure Description

[0015] The embodiments will now be described in detail with reference to the accompanying drawings, wherein:

[0016] Figure 1A An example is shown of a system that includes passive headphones and an audio controller;

[0017] Figure 1B and 1C An example is shown of a system comprising passive headphones, an audio controller, and a computer;

[0018] Figure 2 An example shows an audio controller;

[0019] Figure 3 An example is shown: a computer;

[0020] Figure 4 An example is shown of a method for calibrating passive headphones.

[0021] The accompanying drawings are for illustrative purposes only, and the embodiments are not limited to the portions shown, and modifications may be made within the scope defined in the claims. The drawings may not fully represent the claimed invention and are intended to aid in understanding the technical background and related fields. Detailed Implementation

[0022] This invention provides a system comprising passive headphones and an audio controller, wherein the passive headphones are connected to the audio controller via a wired connection. The audio controller includes an amplifier that enables the connected passive headphones to output audio. The audio controller can be connected to a computer. The computer can perform data transfer to the audio controller and view and adjust the settings of the audio controller, thereby regulating the audio output to the passive headphones. The manufacturer has measured factory calibration data for each passive headphone. The measured factory calibration data is associated with an identifier (e.g., a serial number attached to or associated with the passive headphone) and is stored, for example, in a cloud server. The factory calibration data can be accessed using the identifier of the passive headphone. Each passive headphone has unique factory calibration data associated with its unique identifier. When the passive headphones connected to the audio controller are put into use or are being used, the factory calibration data can be retrieved via a computer. The audio controller can use the factory calibration data of the passive headphones to adjust the frequency response of the passive headphones. The audio controller performs signal processing to enhance the frequency response of the passive headphones. Applying the unique factory calibration data of the passive headphones has a positive impact on the characteristics and performance of the passive headphones.

[0023] Aural sound refers to changes in air pressure exceeding the human hearing threshold within the audible frequency range. Aural sound covers a frequency range from 20 Hz to 20,000 Hz. Sound level is measured in decibels (dB SPL) and is defined as the root mean square (RMS) value of the pressure change divided by the decimal logarithm of the human hearing pressure threshold (accepted to be 20 micropascals, µP), multiplied by 20. The RMS value refers to the continuous power output of an amplifier. Sound can be recorded, stored, and played back as an electrical signal proportional to the instantaneous sound pressure. This electrical signal can be converted into a numerical representation, for example, by an analog-to-digital converter (ADC) to convert the electrical signal into a digital representation of sound. Such electrical signals can be processed by a signal processor. Audio signals refer to the electrical representation of any sound, typically music and speech. In headphones, electroacoustic signals are converted into audible sound by transducers.

[0024] Factory calibration data refers to data determined separately or jointly for the left and right sides of each passive headphone, such as filter settings. Left and right refer to the left earcup containing the left ear transducer and the right earcup containing the right ear transducer, respectively. Factory calibration allows manufacturers to standardize the passive headphones they produce, ensuring all headphones maintain consistent acoustic characteristics, for example, setting the headphones' acoustic characteristics to neutral (i.e., subjectively colorless). This also applies to the left and right earcups, where the left and right sides of the passive headphones will exhibit similar acoustic characteristics. Third, factory calibration ensures that the transduction efficiency of the passive headphones and their earcups is at least substantially consistent, thus keeping the conversion sensitivity (i.e., the sound pressure level produced at a given electronic drive amplitude) of the passive headphones identical. Therefore, factory calibration can both reduce or eliminate undesirable left-right balance deviations within a frequency range and ensure all passive headphones exhibit the same acoustic characteristics, or reduce these effects to an inaudible level, or at least control them within acceptable tolerances.

[0025] Binaural headphones consist of a transducer system for each of the user's ears. The transducer system may contain one or more electroacoustic transducers for converting audio signals into sound. Headphones can be positioned relative to the ears in several ways. Over-ear (i.e., over-ear) headphones are designed to sit on the head and completely cover the user's outer ear (auricle). On-ear (on-ear) headphones are designed to sit on the user's outer ear (auricle). Supraconcha headphones are designed to sit in the outer auricle area of ​​the user's outer ear. In-ear and earbud headphones are designed to deliver audio directly into the user's ear canal. Over-ear headphones typically have cushioning to improve listening comfort. Furthermore, this structure allows for an effective and repeatable seal of the headphone cavity to prevent fluctuations in the headphone's frequency response caused by pressure leakage inside the headphones. Such fluctuations in the headphone's frequency response can have a significant impact, reducing the expected repeatability of the headphone's frequency response.

[0026] The identifier contains a unique, headphone-specific identifier for each passive headphone. This identifier may include the passive headphone's serial number, or other identifiers such as electronic tags, radio frequency identification (RFID) tags, memory chips, or components physically integrated into the headphone, or any such uniform identifier or transponder. This identifier may be attached to each passive headphone, associated with each passive headphone, and / or reside within or be attached to each passive headphone. This identifier enables the unique identification of a specific headphone.

[0027] Factory calibration data can be retrieved based on its associated identifier. At the factory, the factory calibration data for a specific passive headphone is stored in the audio controller that is paired with and packaged with it. Additionally, factory calibration data can be stored on servers, computers, remote devices, external storage, cloud servers, or other storage media accessible via a computer. Factory calibration data can be accessed wirelessly or via wired connections to communication networks or the Internet.

[0028] Passive headphones include one or more transducers configured to generate sound pressure in response to an electrical input. The electrical input contains an audio signal. Additionally, passive headphones may include passive electronic components configured to enable connectivity and distribute the electrical input to multiple transducers. Passive headphones lack active amplifier components and power supply components, which generate electrical drive signals (such as voltage or current) to drive the transducers and produce the audio output. Passive headphones are configured to connect to an audio controller that includes active amplifier components and a power supply component. This audio controller is configured to transmit the electrical input (audio signal) to the passive headphones via a wired connection. The audio controller may also include a signal processor, an analog-to-digital converter, and / or a digital-to-analog converter. Because passive headphones do not contain a power supply or generator amplifier, battery depletion is avoided. In contrast, wireless active headphones with built-in wireless audio interfaces, amplifiers, and power supply components suffer from audio transmission delays and potential sound quality degradation. The issues of latency and sound quality variation typically stem from the fact that wireless audio signal interfaces must encode audio signals into a format that can be efficiently transmitted to active headphones. This often leads to changes in audio resolution and fidelity, especially considering that the power required for this processing and amplification is provided by the active headphones' built-in power supply (usually a rechargeable battery). Encoding the audio signal and wirelessly transmitting it to the headphones takes time, resulting in latency in the audio signal and output. Because passive headphones lack energy storage components or batteries and are connected to an amplifier via a cable to an audio controller, they completely avoid these problems of sound quality degradation and latency. The audio data processing in passive headphones is handled by an external audio controller, eliminating the need for latency-inducing audio encoding.

[0029] Due to variations in the components used in production, there is typically a certain degree of variation between manufactured headphones. These variations can be caused by manufacturing processes or the components themselves. Essentially, the frequency response of a mechanical acoustic reproduction system (such as headphones) often exhibits subtle differences. This can lead to undesirable variations in timbre reproduction and affect the sound balance between the left and right sides of a passive headphone at different frequencies. To eliminate these variations, each passive headphone undergoes factory calibration to compensate for potential deviations. Factory calibration ensures that each headphone delivers a neutral sound quality, all headphone units have consistent sound characteristics, and that the left and right sides of each headphone are perfectly synchronized after factory calibration. After the headphones are manufactured, factory calibration measurements are performed separately for the left and right sides of each passive headphone before shipment. The measured factory calibration data for all manufactured passive headphones allows for adjustment of the frequency response to the desired level. Because similar processing can be applied to the left and right sides of the headphones, the mono sound image presented by at least substantially the same audio signal from the left and right earcups can be precisely positioned in the center of the listener's sound field, and the center sound image can be prevented from shifting with frequency.

[0030] In the final measurement stage of the headphone assembly process, factory calibration settings are measured, and each passive headphone is tested. Measurements cover both earcups or both sides of the headphone. Measurements for each earcup may include impedance, sensitivity, sound level, and phase of the acoustic output across all frequencies, particularly the mid-frequency range of 500 Hz to 6 kHz. The measurement results are compared to predetermined target values, which are determined to achieve ideal subjective timbre and performance. These target values ​​can be a neutral, colorless perception of the sound output for the listener, and an accurate representation of the sound image localization for specific electrical inputs to the left and right ear transducers. For example, the timbre can be adjusted to transmit a neutral sound shape for a diffuse field timbre reference loudspeaker setting, as specified in IEC 60268-7 (International Electrotechnical Commission, 2010 and other versions) and / or ITU BS.708 (International Telecommunication Union, Broadcasting Service, 1990-06 and other versions). Another target value is the free-field target value, which relates to listening conditions with no acoustic reflections and only direct sound from the sound source. In an alternative embodiment, the change in the Harman target curve can be used as the target value. The Harman target curve may include the headphone target curve, which has an ideal frequency response and is expected to meet the expectations and preferences of most listeners.

[0031] Because headphones eliminate the natural effects of the head, torso, and outer ear, they can be configured with specific settings to simulate these effects, collectively known as the Head Related Transfer Function (HRTF). As is well known, HRTF is individual-specific and varies from person to person. Once an individual's HRTF parameters are determined, binaural processing technology can use this information to render audio for headphones, making the sound signal appear as if it were coming from outside the head and from a specific location relative to the listener. Factory calibration of the headphones further enhances the reliability and accuracy of this type of binaural audio processing.

[0032] Neutral sound refers to sound that is reproduced without coloration across the entire audible frequency range. Headphones with neutral sound characteristics subjectively present a balanced, realistic, accurate, and pure reproduction of the original audio data. In other words, truly neutral headphones can reproduce the sound of every frequency with a subjectively equal degree across the entire audible range, with subjective variations within the frequency range of less than 3 dB. For example, a neutral frequency response has a balanced low, mid, and high frequency range, where the low frequency range is 20 to 250 Hz, the mid frequency range is 250 Hz to 6 kHz, and the high frequency range is 4 to 20 kHz. Conversely, non-neutral headphones exhibit areas of over- or under-response. Furthermore, due to potential differences between the left and right sides of the headphones, undesirable frequency-dependent variations in the left-right balance of the audio presentation may occur. Audio data mixing or mastering personnel may experience auditory misjudgments due to areas of over- or under-response and inaccurate frequency-dependent left-right balance.

[0033] Figure 1A A system comprising passive headphones and an audio controller is shown as an example. The passive headphones 101 do not have any power supply or electrical components. The passive headphones 101 include one or more transducers configured for outputting sound. The passive headphones 101 are connected to the audio controller 102. This connection is a cable connection. Figure 1A In this example, connecting cables are provided on both sides of the headphones. In other examples, only one side of the headphones is connected to the audio controller 102. The audio controller 102 includes connection ports for the left and right sides of the headphones, respectively, and also has a single connection port that can be connected to either side of the headphones. The audio controller 102 includes memory, amplifiers, power supply components, and devices and / or signal processing functions for amplifying, controlling, processing, and setting variables or parameters that affect the audio signal transmitted to the passive headphones 101. Factory calibration data may be stored in the memory of the audio controller 102. The audio controller 102 is configured to process and electrically drive input signals to one or more transducers of the headphones 101, which are configured to generate audio output. The factory calibration data is applied to an electrical signal that is input to the headphones 101.

[0034] Figure 1B and 1CA system comprising passive headphones, an audio controller, and a computer is shown in an exemplary manner. Headphones 101, lacking electronic components or processing units, can be considered a passive device. Passive headphones 101 are connected to an audio controller 102. Amplification and sound control are performed in the audio controller 102 connected to the passive headphones 101. The audio controller 102 is further connected to a computer 103, which may be a desktop computer, laptop computer, or smartphone. This connection may be wired. The computer 103 supports internet access, external terminals, and / or storage 104. The computer 103 can retrieve or receive pre-stored factory calibration settings from remote storage 104 using identifiers (such as serial numbers or other unique identifiers) within the passive headphones 101. The computer 103 transmits these settings to the audio controller 102, which uses the factory calibration settings to process the signal for the connected passive headphones 101. The output of the passive headphones 101 is always provided by the audio controller 102. Audio controller 102 includes devices and / or signal processing functions for amplifying, controlling, processing, and setting variables or parameters that affect the audio signal transmitted to passive headphones 101. Computer 103 can transmit, download, or stream audio data to headphones 101 via audio controller 102. Audio controller 102 may include input interfaces to allow audio signals to be directly input to audio controller 102 for processing and transmission to headphones 101. Audio controller 102 supports adjustment of the sound of headphones 101. Audio processing is performed in audio controller 102 when sound data is streamed via computer 103. This allows computer 103 to handle other tasks simultaneously without consuming significant processing power or bandwidth resources. The signal processing functions of audio controller 102 can be performed remotely, for example, in a cloud computing server, rather than relying on an actual audio controller 102 connected to headphones 101.

[0035] exist Figure 1B In this configuration, the amplifier output of the audio controller 102 is connected to the right (R) earcup of the headphones 101. Figure 1CIn this design, the amplifier output of the audio controller 102 is connected to the left (L) earcup of the headphones 101. Passive headphones may include connection ports located in both earcups. Therefore, the user can connect the audio controller 102's cable to either earcup. This design optimizes ergonomics and ensures optimal connectivity in all usage scenarios. The factory calibration settings for the left and right earcups are set independently. Factory calibration can be performed individually for any conditions that might cause changes in the headphone's frequency response (potentially due to variations in the headphone's cushioning and / or surface materials). The earcups are labeled to distinguish between the left and right earcups. The audio controller 102 has the function of identifying, distinguishing, and differentiating between the left and right sides of the headphones (i.e., the left and right earcups). Identification can be performed automatically or in response to user input. The user can input information describing the current configuration of the headphones 101. The identification function can select the correct factory calibration data for the left and right sides of the headphones. The audio controller 102 can apply measured calibration settings to the left and right earcups separately.

[0036] Passive headphones can be connected to an audio controller via: Universal Serial Bus (USB) cable, analog audio cable (such as an auxiliary audio line, AUX), High Definition Multimedia Interface (HDMI) cable, fiber optic or coaxial cable, etc. When a passive headphone is connected to an audio controller, the latter can recognize the passive headphone. The passive headphone's identifier can be transmitted to the audio controller via the connection. Additionally, the audio controller can receive information about whether it is connected to the left or right side of the headphone. This information is transmitted by the headphone in response to the connection with the audio controller. The left and right sides of the headphone may have identifiers, which are transmitted in response to the connection with the audio controller. Alternatively, the audio controller can request this information in response to the connection with the headphone. In addition to information about which side of the headphone is connected, the audio controller can also receive the headphone's identifier. The audio controller may also have factory calibration data stored in its memory. After factory calibration measurements are completed in the factory, the measured factory calibration data of the headphone can be stored in the audio controller paired with the headphone. In response to receiving the identifier of the paired headphone, the audio controller can apply the factory calibration data to the electrical signal output to the headphone. If the received identifier is not the one paired with the audio controller, the audio controller can receive factory calibration data via the computer by transmitting the headphone identifier to the computer. The headphone identifier can be attached to the headphones. The audio controller can read the identifier and additional information using radio frequency or other short-range signaling. For example, a passive RFID tag can be attached to the headphones and read by the audio controller, which includes a reader or has an external reader. In one embodiment, the user can input the headphone identifier (and optional additional information) into the computer. The computer can access a data storage device that stores factory calibration data associated with a specific headphone identifier. The computer can receive factory calibration setting parameters in response to transmitting the identifier to the data storage device. The stored factory calibration setting parameters contain calibration information for the left and right sides of the headphones. The audio controller has information about which side of the headphones it is connected to. The audio controller can correctly apply the factory calibration data to both sides of the headphones.

[0037] Passive headphones can be replaced or replaced with new headphones while retaining the same audio controller. In this case, the new passive headphones will be connected to the (used) audio controller. The factory calibration settings of the new passive headphones are obtained through their identifier (such as a serial number). The computer receiving the factory calibration settings transmits this information to the audio controller for signal processing of the new passive headphones. In this way, passive headphones can be replaced and / or replaced with passive headphones having independent factory calibration settings while keeping the audio controller unchanged, ensuring consistent, accurate, and neutral sound characteristics. Furthermore, a single audio controller can support multiple passive headphones, but only one at a time. For example, in a workplace, the same audio controller can be used in rotation by multiple different passive headphones and their users.

[0038] Figure 2 An audio controller is shown as an example. This audio controller includes input ports and output ports for inputting and outputting audio data, respectively. The audio controller may include input ports for analog audio data in the left (L) and right (R) channels, and corresponding output ports for analog audio data in the left (L) and right (R) channels. The audio controller may also include input / output (I / O) ports for digital audio data. For example, the audio controller may include headphone input / output (I / O) ports, a Universal Serial Bus (USB) connection port, or other connection ports such as cable, AUX, HDMI, coaxial, or similar ports. The audio controller includes a battery, a user interface (UI), and a signal processor (SP). The audio controller includes an amplifier (Amp), which may be a headphone amplifier integrated within the audio controller. The amplifier may amplify current, voltage, or power. The amplifier (Amp) may be a power amplifier configured to convert a low-power signal to a high-power signal by increasing the input power. A power amplifier, also known as a large-signal amplifier, is configured to provide high power to the input audio signal. Power amplifiers can provide greater output power, but they tend to be larger and heavier than non-power amplifiers. However, these size and weight issues primarily affect active headphones with integrated audio controllers, and have no impact on the size and weight of passive headphones. Furthermore, the audio controller may include one or more transducers, as well as a digital-to-analog converter (DAC). The audio controller is configured to control audio data.

[0039] Audio controllers can be portable or mobile. The difference between portable and desktop audio controllers lies in size: desktop controllers are fixed in one location (such as a recording studio), while portable controllers are portable, smaller, and lighter than desktop controllers. Portable controllers may have fewer features and adjustment options compared to desktop controllers. Desktop controllers are powered by AC power via a wall outlet, while portable controllers can be powered by AC power, batteries, or rechargeable AC power supplies.

[0040] The audio controller can be connected to passive headphones via I / O ports. It can also be connected to a computer via a USB port. Both connections can be wired. Wired connections avoid latency and other issues associated with wireless networks due to location or network conditions. The audio controller is configured to receive factory calibration settings measured and stored for a specific passive headphone. These factory calibration settings can be stored within the audio controller and / or received from a computer. The audio controller is configured to apply the factory calibration settings to all input signals to the passive headphones.

[0041] Audio signals can be reproduced in digital or analog formats, and audio signal processing can be based on either format. Analog signal processors operate directly on electrical signals, while digital signal processors perform mathematical operations on the digital representation of electrical signals. Audio controllers are used to balance and adjust sound sources. Audio controllers may include equalizers (EQ) and / or processors, the latter configured to process the dynamics, effects, mixing, reproduction, and enhancement of sound. Equalization (EQ) processing includes adjusting the volume of different frequency bands in the audio signal. Audio filters may include frequency-dependent circuitry for amplifying (boosting), passing, or attenuating (cutting off) specific frequencies or frequency bands. Compression, or dynamic range compression (DRC), is configured to reduce the volume of loud sounds or amplify weak sounds, thereby reducing or compressing the dynamic range of the audio signal. Compression functionality can be implemented by a compressor, which can be a dedicated electronic hardware device or audio software.

[0042] An audio controller includes devices and / or signal processing functions for amplifying, controlling, processing, and setting variables or parameters that affect the audio signal transmitted to passive headphones. A computer can transmit, download, or stream audio data to the headphones via the audio controller. The audio controller may include input interfaces to allow audio signals to be directly input to the audio controller for processing and transmission to the headphones. The audio controller can adjust the input electrical signals to provide sound through the passive headphones.

[0043] Figure 3A computer is illustrated exemplarily. The computer includes a processor, which serves as the central processing unit of the computer. The processor may include a microprocessor, a computer processor, or an integrated circuit (IC). The computer includes memory (MEM). The memory may include non-volatile memory and / or multiple storage units, such as read-only memory (ROM), random access memory (RAM), flash memory, etc. The memory (MEM) may contain executable instructions that can be executed by the processor. The memory is configured to store information, executable instructions, and / or at least one application that can communicate with an audio controller. The computer includes a battery and a user interface. The user interface may include input and output devices for user use, such as a display screen, buttons, and a touchscreen. The computer is equipped with physical ports for wired connections. These ports include input / output ports (I / O) and universal serial bus ports (USB). The computer may include other ports for connecting external devices and / or terminals. The computer includes a transmit branch (TX) and a receive branch (RX). The transmit / receive branch (TX / RX) may include a receiver / transmitter, a digital-to-analog converter, an analog-to-digital converter, an amplifier, and an antenna. The transmitting branch (TX) is configured to transmit data and / or signals via a wireless connection. The receiving branch (RX) is configured to receive data and / or signals via a wireless connection. This wireless connection can be a radio frequency network, a cellular network, or a communication network, enabling the exchange of data and information. Furthermore, the computer may include transmission devices configured for short-range wireless communication, such as Bluetooth, infrared, etc. The computer can connect to the internet via a modem, which can access the internet via a wired or wireless connection (such as Wi-Fi compliant with the IEEE 802.11 standard).

[0044] The computer may include a mobile computer, mobile device, handheld computer, smartphone, desktop computer, laptop computer, tablet computer, or any suitable device. The computer may include means for acquiring factory calibration setting parameters in response to a received identifier of the passive headphones, and means for transmitting the factory calibration setting parameters to the audio controller. The computer may include a software application configured for communicating with the audio controller. This application may provide a user interface to receive user input and output information to the user.

[0045] Figure 4An exemplary method for calibrating passive headphones is shown. The passive headphones are connected to an audio controller. The method includes step 401, where the audio controller acquires factory calibration data. The factory calibration data is specific to the passive headphones and associated with an identifier for the passive headphones. The method also includes step 402, where the audio controller applies the factory calibration data to an electrical signal input to the passive headphones. The method may include amplifying the electrical signal transmitted to one or more transducers of the passive headphones by a headphone amplifier integrated into the audio controller, and having the passive headphones reproduce the electrical signal as sound. The method may include pre-storing the factory calibration data in an audio controller paired with the passive headphones and in remote memory. The method may include applying the factory calibration data by the audio controller to adjust the frequency response of the passive headphones. The method may include receiving the factory calibration data from a computer. The computer may be configured to access remote memory to receive the factory calibration data in response to providing an identifier for the passive headphones. The method may include automatically receiving the identifier by the audio controller in response to connection to the passive headphones, and / or receiving the identifier via short-range signaling from the passive headphones. The method may include receiving an identifier by a computer via short-range signaling, and / or receiving an identifier by a computer from an audio controller. The method may also include, when a passive headset is connected to an audio controller, the audio controller automatically receiving information about which side of the passive headset it is connected to via the connection cable between the audio controller and the passive headset and / or via short-range signaling.

[0046] In the foregoing description and accompanying drawings, the passive headphones are activated by connecting to an audio controller, which can also obtain factory calibration settings for a specific passive headphone via a computer. The system employs a modular design. This allows any one of the passive headphones, audio controller, or computer to be individually replaced or substituted. For example, replacing the passive headphones has no impact on other modules of the audio controller and computer, but the system equipped with the new passive headphones still achieves the same connection accuracy, calibration accuracy, and performance quality as the original headphones.

[0047] A computer can receive audio data streams or download audio data via passive headphones. The audio data is then transmitted from the computer to an audio controller. This audio controller is configured to process, calibrate, and / or equalize the audio data. Audio signal processing, or all audio signal processing, is performed at the audio controller. The computer does not require additional computing power or transmission resources.

[0048] Head-Related Transfer Function (HRTF) is used to provide a 3D audio experience for headphone users. HRTF constructs a 3D model of the user using images of their head, torso, and / or auricle. HRTF describes an acoustic filter that quantifies the influence of the shape of the head, torso, and auricle on the sound reaching the ear canal entrance. The baseline value of HRTF can be pre-determined using methods such as loudspeakers in a listening room. With HRTF technology, each passive headphone can be matched to a preset auditory experience (e.g., multiple loudspeakers in a listening room). Thus, the response characteristics of the passive headphone correspond to the acoustic simulation of the room. Factory calibration settings ensure the quality of the passive headphone within a specific tolerance range. After factory calibration, a personalized 3D audio experience can be achieved using a personal HRTF. This enables a high-quality, user-customized audio experience. Without factory calibration settings, differences between different headphones may lead to further deviations and / or problems when using HRTF.

[0049] Listeners can adjust their headphones. Headphones are calibrated at the factory to produce a natural or balanced sound. The playback effect is predictable. After the natural reproduction of factory calibration, listeners can select settings for their headphones. For example, listeners can choose so-called "warmth" to enhance low-frequency performance (i.e., low or mid-low frequencies). In warmth, low frequencies dominate relative to high frequencies. Warmth can be described as bass-heavy. The opposite of warmth is so-called "brightness," which enhances high-frequency performance. In brightness, high frequencies dominate relative to low frequencies. The audible frequency range for most people is approximately 20 Hz to 20 kHz, encompassing about 20,000 different frequencies. In a recording studio environment, the entire spectrum of different components, such as instruments, can be controlled, adjusted, and mixed. The frequency response of a signal reflects the amount (volume) of each frequency within the human audible range. The frequency response can be edited in various ways, such as through equalization and filtering. Equalizers are used to change specific parts of the signal's frequency response. Filters are used to attenuate specific parts of the audio spectrum. Audio mixing refers to the process of optimizing and integrating multitrack recordings into a final sound product. Mixing may involve adjusting and balancing the relative levels of individual tracks in a multitrack recording, which may involve equalization and compression processing. The system described herein, comprising an audio controller, passive headphones, and a computer, is an alternative to a mixer (also known as a mixing console, mixing dock, mixing board, or software mixer). Mixing can be achieved through software or applications downloaded or installed on a computer, with the audio controller configured to handle signal processing. While mixing consoles are bulky and have numerous control knobs, the system proposed in this application provides a portable system for mixing. Although the system has fewer control knobs than a large, stationary mixing console, its portability allows for location-independent mixing operations and enables instant mixing.

[0050] It should be understood that the embodiments disclosed herein are not limited to the specific structures, process steps, or materials described herein, but can be extended to equivalents recognized by those skilled in the art. It should also be understood that the terminology used herein is for describing specific embodiments only and is not intended to be limiting.

[0051] Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Numerous specific details (e.g., examples of length, width, shape, etc.) have been set forth in the foregoing description to facilitate a thorough understanding of embodiments of the invention. However, those skilled in the art will understand that the invention may be practiced without one or more specific details, or with other methods, components, materials, etc. Additionally, known structures, materials, or operations have not been shown or described in detail to avoid obscuring aspects of the invention.

[0052] While the above embodiments illustrate the principles of the invention in one or more specific applications, those skilled in the art will understand that many modifications can be made to the form, use, and details of the implementations without inventive effort and without departing from the principles and concepts of the invention. Therefore, the invention is intended to be limited only by the appended claims.

[0053] The verbs “comprising” and “including” are used herein as open-ended qualifiers, neither excluding nor requiring the presence of other unlisted features. Unless expressly stated otherwise, the features listed in the dependent claims can freely be combined with each other. Furthermore, it should be understood that the use of “a” or “an” (i.e., the singular form) herein does not exclude the plural form.

Claims

1. A system comprising passive headphones (101) and an audio controller (102), wherein: - The passive headphones (101) are connected to the audio controller (102). - The audio controller (102) is configured to acquire factory calibration data specific to the passive earphone (101) and associated with an identifier of the passive earphone (101). - The factory calibration data has been pre-stored in the audio controller and remote memory paired with the passive headphones (101), wherein the pre-stored factory calibration data includes factory calibration data for the left and right sides of the passive headphones (101). - When the identifier of the passive earphone (101) connected to the audio controller is not the one paired with the audio controller, the audio controller is configured to receive the factory calibration data via the computer in response to the transmission of the identifier of the passive earphone (101) to the computer; and - The audio controller (102) is configured to apply the factory calibration data to the electrical signals input to the passive headphones (101).

2. The system according to claim 1, characterized in that, The factory calibration data includes data determined separately for the earphones and for both sides of the earphones (101).

3. The system according to claim 1 or 2, characterized in that, The identifier is specific to the passive earphone (101); and / or, the identifier is a serial number, component, memory chip, transponder, electronic tag, or radio frequency identification (RFID) tag.

4. The system according to any one of claims 1 to 3, characterized in that, The identifier is connected to, associated with, and / or exists within or is attached to the passive earphone (101).

5. The system according to any one of claims 1 to 4, characterized in that, The audio controller (102) includes an integrated headphone amplifier, and the headphones (101) include one or more transducers, wherein the headphone amplifier is configured to amplify electrical signals transmitted to one or more transducers of the passive headphones (101), and the transducers are configured to convert the electrical signals into sound output.

6. The system according to any one of claims 1 to 5, characterized in that, The audio controller is a mobile or portable audio controller.

7. The system according to any one of claims 1 to 6, characterized in that, The factory calibration data includes at least one of the following parameters obtained by measuring both sides of the passive earphone (101): impedance, sensitivity, level, and phase of the acoustic output in response to electrical input, optionally covering all frequencies.

8. The system according to any one of claims 1 to 7, characterized in that, The factory calibration data of the passive headphones (101) applied by the audio controller (102) is configured to adjust the frequency response of the passive headphones (101).

9. The system according to any one of claims 1 to 8, characterized in that, The computer (103) is configured to connect to the audio controller (102), wherein the audio controller (102) is configured to receive factory calibration data from the computer (103), and the computer (103) is configured to access a remote memory (104) to receive factory calibration data stored in the remote memory (104) in response to an identifier provided by the passive headphones (101).

10. The system according to any one of claims 1 to 9, characterized in that, The identifier of the passive earphone (101) is automatically received by the audio controller (102) in response to the connection between the audio controller (102) and the passive earphone (101) and / or through short-range signaling issued by the passive earphone (101).

11. The system according to any one of claims 1 to 10, characterized in that, The identifier of the passive earphone (101) is input to the computer (103), received by the computer (103), received by the computer (103) via short-range signaling, and / or received by the computer (103) from the audio controller (102).

12. The system according to any one of claims 1 to 11, characterized in that, When the passive earphone (101) is connected to the audio controller (102), the audio controller (102) automatically receives information about which side of the passive earphone (101) is connected to via the connection cable between the passive earphone (101) and the audio controller (102) and / or via short-range signaling.

13. The system according to any one of claims 1 to 12, characterized in that, The audio controller (102) is connected to the passive headphones (101) via a wired connection, and / or the audio controller (102) is connected to the computer (103) via a wired connection.

14. The system according to any one of claims 1 to 13, characterized in that, The computer (103) includes at least a processor and a memory, the memory including instructions executable by the processor, and the computer (103) is configured to access remote memory (104).

15. A method for calibrating passive headphones, wherein the passive headphones are connected to an audio controller, the method comprising: - Factory calibration data is acquired by the audio controller, and this factory calibration data is specific to the passive headphones and associated with the identifier of the passive headphones. The factory calibration data is pre-stored in the audio controller and remote memory paired with the passive earphone (101). The pre-stored factory calibration data includes factory calibration data for the left and right sides of the passive earphone (101). When the identifier of the passive earphone (101) connected to the audio controller is not the one paired with the audio controller, the audio controller receives the factory calibration data through the computer in response to the transmission of the identifier of the passive earphone (101) to the computer; and - The factory calibration data is applied by the audio controller (102) to the electrical signal input to the passive headphones (101).

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