A system comprising passive headphones and an audio controller, and a method for calibrating passive headphones.

Abstract

We offer factory calibration for passive headphones. [Solution] A system is provided comprising a passive headphone (101) and an audio controller (102), wherein the passive headphone (101) is connected to the audio controller (102). The audio controller (102) is configured to acquire factory calibration data that is specific to the passive headphone (101) and associated with an identifier of the passive headphone (101), and the audio controller (102) is configured to apply the factory calibration data to the electrical signals input to the passive headphone (101).

Description

Technical Field

[0001] The present invention relates to a system comprising a passive headset and an audio controller, and a method for calibrating a passive headset.

Background Art

[0002] A passive headset does not have an amplifier and a power source (battery) necessary to drive a transducer of the headset to generate an audio output. Therefore, the passive headset is connected to an audio controller having a headset amplifier and power components. The audio controller is configured to send an electrical signal to the passive headset, and these electrical signals are output as sound in the passive headset.

Summary of the Invention

Problems to be Solved by the Invention

[0003] An object is to provide factory shipment calibration of a passive headset.

Means for Solving the Problems

[0004] The present invention is defined by the features of the independent claims. Some embodiments are defined in the dependent claims.

[0005] According to a first aspect of the present invention, a system comprising a passive headset and an audio controller is provided, the passive headset being connected to the audio controller. The audio controller is configured to obtain factory shipment calibration data that is unique to the passive headset and is associated with an identifier of the passive headset, and the audio controller is configured to apply the factory shipment calibration data to an electrical signal input to the passive headset.

[0006] The identifier may be specific to passive headphones; 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 headphones, associated with the passive headphones, and / or available within or with the passive headphones.

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

[0008] Factory calibration data is pre-stored in the audio controller paired with the passive headphones and in remote storage. The factory calibration includes at least one of the following parameters measured for both sides of the passive headphones: impedance, sensitivity, and the level and phase of the acoustic output as a response to electrical input, optionally across all frequencies. The factory calibration 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 embodiment may further include a computer calibrated to be connected to an audio controller, the audio controller being configured to receive factory calibration data from the computer, which is configured to access remote storage to receive factory calibration stored in remote storage in response to an identifier of the passive headphones provided. The computer may include at least a processor and memory containing instructions that the processor can execute, and the computer may be configured to access remote storage.

[0010] The identifier for passive headphones may be automatically received by the audio controller in response to connection to the passive headphones and / or via near-field signaling from the passive headphones. The identifier for passive headphones may be input to a computer, received by the computer, received by the computer via near-field signaling, and / or received by the computer from the audio controller.

[0011] Information regarding which side of the passive headphones the audio controller is connected to is automatically received by the audio controller via the connecting cable between the passive headphones and the audio controller, and / or via short-range signal transmission, when the passive headphones are connected to the audio controller. The audio controller may be connected to the passive headphones via a wired connection; and / or the audio controller may be connected to a computer via a wired connection.

[0012] A second aspect of the present invention provides a method for calibrating passive headphones connected to an audio controller. The method includes: the steps of: obtaining factory calibration data specific to the passive headphones and associated with an identifier for the passive headphones using the audio controller; and applying the factory calibration data to an electrical signal input to the passive headphones using the audio controller.

[0013] According to a third aspect of the present invention, a system comprising passive headphones and an audio controller according to the first aspect is provided for use in audio mixing.

[0014] According to a fourth aspect of the present invention, a system comprising passive headphones and an audio controller according to the first aspect is provided for use in studio mixing.

[0015] The embodiments will now be discussed in more detail with reference to the attached drawings. [Brief explanation of the drawing]

[0016] [Figure 1A] Figure 1A shows an example system comprising passive headphones and an audio controller. [Figure 1B] Figures 1B-1C show an example system comprising passive headphones, an audio controller, and a computer. [Figure 1C] Figures 1B-1C show an example system comprising passive headphones, an audio controller, and a computer. [Figure 2] Figure 2 shows an audio controller as an example. [Figure 3] Figure 3 shows a computer as an example. [Figure 4] Figure 4 shows an example of a calibration method for passive headphones. [Modes for carrying out the invention]

[0017] The figures are presented as illustrative examples, and the embodiments may not be limited to those shown, and modifications may be made within the scope defined in the claims. Figures that may not fully illustrate the claimed invention are intended to provide a deeper understanding of the context and the relevant technical field.

[0018] A system is provided comprising passive headphones and an audio controller to which the passive headphones can be connected via a wired connection. The audio controller includes an amplifier that enables the connected passive headphones to output sound. The audio controller may be connected to a computer. This computer enables data transmission to the audio controller and allows verification and adjustment of the audio controller's settings for adjusting the sound output to the passive headphones. Factory calibration data is measured by the manufacturer for each pair of passive headphones. The measured factory calibration data is associated with an identifier, such as a serial number attached to or associated with the passive headphones, and is stored, for example, in a cloud service. The factory calibration data is accessible using the passive headphone identifier. Each pair of passive headphones has unique factory calibration data associated with its unique identifier. Factory calibration can be obtained via computer when or while the passive headphones connected to the audio controller are in use. The audio controller uses factory calibration data for passive headphones to adjust their frequency response. The audio controller performs signal processing configured to enhance the frequency response of the passive headphones. Applying the passive headphones' unique factory calibration has a positive effect on their characteristics and performance.

[0019] Audible sound is a fluctuation in atmospheric pressure at a frequency range audible to humans, exceeding the human hearing threshold. Audible sound includes frequencies from 20 Hz to 20,000 Hz. Sound level is measured in decibels of sound pressure, i.e., dB SPL (sound pressure level), which is defined as the base-10 logarithm of the root mean square (RMS) value of the pressure fluctuation multiplied by 20, divided by the human hearing threshold, which is considered to be 20 micropascals (μP). RMS refers to the amount of continuous power that an amplifier can output. Sound can be recorded, stored, and played back as an electrical signal proportional to its instantaneous sound pressure. Electrical signals can be converted into numerical representations. For example, an electrical signal can be converted into a digital representation of sound by an analog-to-digital converter. Such electrical signals can be processed by a signal processor. A speech signal refers to the electrical representation of any sound, typically music and speech. In headphones, a transducer is used to convert an electrical speech signal into audible sound.

[0020] Factory calibration refers to data, such as filter settings, that are determined collectively or separately for the left and right sides of each individual passive headphone. 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 the manufacturer to standardize the passive headphones they produce, ensuring all headphones are identical in terms of their acoustic characteristics, for example, achieving a neutral sound quality—that is, subjectively, an uncolored sound. The same applies between the left and right earcups, in which case the left and right sides of the passive headphone become acoustically identical. Thirdly, factory calibration can make the transduction efficiency at least substantially the same across multiple passive headphones and between the earcups of passive headphones, thereby ensuring the conversion sensitivity of the passive headphones—that is, the magnitude of the sound pressure generated for a given amount of electronic driving force—is the same. Therefore, factory calibration not only reduces or eliminates unwanted fluctuations in left-right balance across the entire frequency range, but also ensures the same sound quality across all passive headphones, or reduces these effects to an inaudible level or at least to an acceptable level.

[0021] A binaural headset comprises a transducer system for each ear of the user. The transducer system may comprise one or more electro-acoustic transducers configured to reproduce sound from audio. The headset can be arranged in various ways for one or more ears. Over-ear, or circumaural, headphones are configured to be worn on the head and completely cover the user's outer ear (pinna). On-ear (supra-aural) headphones are configured to be worn on the user's outer ear (pinna). Supra-concha headphones are configured to be worn in the concha area of the user's outer ear. In-ear (intra-concha) and insert headphones are configured to deliver audio directly into the user's ear canal. Typically, cushions are used for comfortable listening for head mounting. Further, by making it possible to effectively and reproducibly seal the volume inside the headphones, it is possible to avoid variations in the frequency response of the headphones due to pressure leakage inside the headphones. Otherwise, such variations in the frequency response of the headphones can be significant and reduce the reproducibility of the intended headphones frequency response.

[0022] The identifier includes a unique and headset-specific identifier of the passive headset. The identifier can include the serial number of the passive headset, or other identifiers such as an electronic tag, radio frequency identification (RFID) tag, memory chip, or component physically integrated into the headset, or any such integrated device or transponder. The identifier may be attached to, associated with, and / or made available within or with each passive headset. The identifier enables the unique identification of a particular headset.

[0023] Factory shipment calibration can be obtained based on an identifier associated with that factory shipment calibration. In the factory, the factory shipment calibration of a particular passive headset is stored in an audio controller that is paired with and shipped together with the passive headset. Further, the factory shipment calibration can also be stored in a server, computer, remote device, external memory, cloud-based service, or similar storage accessible by a computer, for example. The factory shipment calibration may be wirelessly accessible or accessible using, for example, a cable connection to a communication network or the Internet.

[0024] Passive headphones comprise one or more transducers configured to generate acoustic pressure in response to an electrical input, including an audio signal. Furthermore, passive headphones may include passive electronic components configured to provide connectivity and split the electrical input into multiple transducers. Passive headphones do not include active amplifier and power supply components configured to generate an electrical driving force, such as voltage or current, to drive the transducers and produce an audio output. Passive headphones are configured to connect to an audio controller comprising active amplifier and power supply components. The audio controller is configured to transmit the electrical input (audio signal) to the passive headphones using a wired connection. The audio controller may further include a signal processor, analog-to-digital and / or digital-to-analog converters. Because passive headphones do not have a power supply or amplifier to generate power, battery depletion of the passive headphones is avoided. In contrast, wireless active headphones, which incorporate a wireless audio interface, amplifier, and power supply components, suffer from audio transmission delays and may experience degradation of audio quality. Problems with delay and changes in audio quality typically arise from the following: Wireless audio signal interfaces must encode the audio signal into a format that can be effectively transmitted to active headphones, which often leads to changes in audio resolution and fidelity, especially considering that power for such processing and amplification must be supplied by power components and (typically rechargeable) batteries built into the active headphones. Encoding and wirelessly transmitting the audio signal to the headphones takes time, resulting in delays in the audio signal and output. Passive headphones, which do not have power storage components or batteries and have a cable connection to the amplifier of the audio controller, can avoid all of these audio quality degradation and delay problems. In passive headphones, the processing of audio data is handled by an external audio controller, eliminating the need for audio encoding that causes delays.

[0025] Typically, manufactured headphones will have some degree of variation from one another due to variations in the components used during manufacturing. These variations can be caused, for example, by the manufacturing process or components themselves. By their very nature, mechanical sound reproduction systems like headphones typically have slightly different frequency responses. This can lead to undesirable variations in timbre and the balance of sound as a function of frequency between the left and right sides of a passive headphone. To avoid variations between headphones, each passive headphone is calibrated at the factory, and any possible variations are compensated for by factory calibration. Factory calibration ensures that, when applied, the sound of each headphone is neutral and that the same sound quality is achieved across all headphone units and between the left and right sides of each headphone. Factory calibration measurements are performed after the headphones are manufactured, for each side of each individual passive headphone, and before the headphones are shipped. The left and right sides of the passive headphone are measured separately. Measured factory calibration allows for the adjustment of the frequency response of all manufactured passive headphones to achieve the desired frequency response. Because the left and right sides of the headphones can be made identical, the monophonic sound image, represented by the sound being at least substantially the same in the left and right earcups, can be adjusted to appear precisely in the center of the presented sound for the listener, and frequency-dependent fluctuations in this central image can be avoided.

[0026] The factory calibration settings are measured at the end of the headphone assembly process, and each passive headphone is measured. Both earcups of the headphones, or both sides, are measured. The measurements per earcup include the impedance, sensitivity, level, and phase of the acoustic output for all frequencies, particularly the mid-range frequencies which may be 500 Hz to 6 kHz. These measurements may be compared to predetermined target values, which can be determined to obtain the desired subjective timbre and performance. This target may be that the listener perceives a neutral and uncolored sound output, and that the position of the sound image relative to a given electrical input is accurately presented to the left and right ear transducer systems. For example, timbre can be adjusted to produce a neutral sound for diffuse-field timbre reference speaker configurations, such as those specified in IEC 60268-7 (International Electrotechnical Commission (IEC), 2010 and other versions) and / or ITU BS.708 (International Telecommunication Union (ITU), Broadcasting Service (BS), approved June 1990 and other versions). Another target is the free-field target, which relates to listening conditions where there are no acoustic reflections and only direct sound from the sound source. As an alternative, variations of the Harman Target Curve can be used as a target. The Harman Target Curve can consist of a headphone target curve that is an ideal frequency response expected to satisfy the expectations and preferences of most listeners.

[0027] Because headphones eliminate the natural influences of the head, torso, and outer ear, they can be configured to emulate these natural influences, collectively known as the Head-Related Transfer Function (HRTF). HRTFs are known to vary from person to person and are unique to each individual. Once an individual's HRTF is determined, binaural processing can use this HRTF information to create audio for headphone listening that feels as if the audio signal is outside the head and positioned in a specific direction for the listener. Factory calibration of headphones can make this binaural audio processing more reliable and precise.

[0028] Neutral sound refers to reproduced sound without coloration across the entire audible frequency range. Headphones with neutral sound quality subjectively provide a uniform, straightforward, authentic, and / or pure representation of the original audio data. In other words, truly neutral headphones reproduce all frequencies of sound across the entire audible range with a subjectively uniform scale, and the subjective variation across that frequency range is less than 3 decibels. For example, a neutral frequency response has a balanced bass, mid, and treble frequency range, where the bass range can be described as 20-250 Hz, the midrange as 250 Hz-6 kHz, and the treble as 4-20 kHz. In contrast, non-neutral headphones have areas where the responsiveness is excessive or lacking. Furthermore, there may be differences between the left and right sides of the headphones, which can result in undesirable frequency-dependent variations in the left-right balance of the presented sound. Those mixing or mastering audio data may have their hearing misled by areas of excessive or insufficient responsiveness, or by frequency-dependent, inaccurate left-right balance.

[0029] Figure 1A shows, as an example, a system comprising passive headphones and an audio controller. The passive headphones 101 do not contain any electrical or power supply components. The passive headphones 101 include one or more transducers configured to output sound. The passive headphones 101 are connected to the audio controller 102. This connection is a cable connection. In Figure 1A, there are connection cables on both sides of the headphones. In other examples, only one side of the headphones may be connected to the audio controller 102. The audio controller 102 includes separate connection ports for the left and right sides of the headphones, as well as 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 equipment and / or signal processing functions for amplifying, controlling, and processing the audio signal sent to the passive headphones 101, and for setting processing variables or parameters that affect the audio signal. Factory calibration data can be stored in the memory of the audio controller 102. The audio controller 102 processes the input signal and electrically sends this input signal to one or more transducers in the headphones 101, which are configured to generate audio output. Factory calibration data is applied to the electrical signal input to the headphones 101.

[0030] Figures 1B and 1C show, as an example, a system comprising passive headphones, an audio controller, and a computer. Headphones 101, which do not contain electronic or processing components, can be considered a passive device. Passive headphones 101 are connected to an audio controller 102. Amplification and sound control are implemented 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, laptop, or smartphone. The connection may be wired. The computer 103 enables connection to the internet, external terminals, and / or storage 104. The computer 103 can retrieve or receive pre-stored factory calibration settings from remote storage 104 using an identifier such as a serial number or other unique identifier located in the passive headphones 101. The computer 103 transmits these settings to the audio controller 102, which uses the factory calibration settings to process one or more signals for the connected passive headphones 101. The output of the passive headphones 101 is always provided by the audio controller 102. The audio controller 102 includes equipment or signal processing functions for amplifying, controlling, and processing the audio signal sent to the passive headphones 101, and for setting processing variables or parameters that affect the audio signal. The computer 103 can deliver, download, or stream audio data to the headphones 101 via the audio controller 102. The audio controller 102 may include inputs that allow audio signals to be sent directly to the audio controller 102 for processing and sending the audio signal to the headphones 101. The audio controller 102 can adjust the sound of the headphones 101. When streaming audio data via the computer 103, audio processing is performed in the audio controller 102. This allows the computer 103 to be used for other purposes without significantly reducing its processing power or bandwidth.The signal processing functions of the audio controller 102 can also be performed remotely, for example, through a cloud computing service, instead of using the physical audio controller 102 connected to the headphones 101.

[0031] In Figure 1A, the output of the amplifier of the audio controller 102 is connected to the right (R) ear cup of the headphones 101. In Figure 1B, the output of the amplifier of the audio controller 102 is connected to the left (L) ear cup of the headphones 101. Passive headphones can have connection ports on both ear cups. Therefore, the user can connect the cable from the audio controller 102 to either of the headphone's ear cups. This improves ergonomics and supports optimal connectivity in all usage situations. Factory calibration settings are created separately for both the left and right ear cups. Factory calibration can be performed individually for any case in which changes in the headphone's frequency response occur, which may be caused by changes in the headphone's cushioning material and / or surface material. The ear cups are identified to distinguish between the two ear cups. The audio controller 102 can identify, recognize, and distinguish between the left (L) and right (R) sides of the headphones. Recognition may be automatic or may be performed in response to user input. The user can input information to describe the current configuration of the headphones 101. Recognition allows the correct factory calibration to be selected for the left (L) and right (R) sides of the headphones. The audio controller 102 can use the measured factory calibration settings for the left (L) ear cup and the right (R) ear cup, respectively.

[0032] Passive headphones can be connected to an audio controller via, for example, a universal serial bus (USB) cable, an analog cable known as an auxiliary (AUX) cable, a high-definition multimedia interface (HDMI®) cable, or an optical or coaxial cable. When passive headphones are connected to an audio controller, the audio controller can identify them. The identifier of the passive headphones can be transmitted to the audio controller via the connection. Furthermore, the audio controller can receive information about whether it is attached to the right or left side of the headphones. This information can be transmitted from the headphones in response to their connection to the audio controller. The left and right sides of the headphones may have identifiers, which are transmitted in response to the connection to the audio controller. Alternatively, the audio controller may request the above information in response to the connection of the headphones. In addition to information about which side of the headphones it is attached to, the audio controller can receive the headphone identifier. The audio controller may have factory calibration data stored in its memory. The measured factory calibration data of the headphones can be stored in the audio controller paired with the headphones after the factory calibration measurement at the factory. The audio controller can apply the factory calibration to the electrical signal output to the headphones in response to receiving the identifier of the paired headphones. If the received identifier is not one paired with the audio controller, the audio controller can receive the factory calibration via the computer in response to the headphone identifier being sent to the computer. The headphone identifier may be attached to the headphones.The identifier and information regarding which side of the headphones the audio controller is connected to can be read by the audio controller using radio frequency or other short-range signaling. For example, a passive RFID tag may be attached to the headphones and read by an audio controller having a reader device or attached to a reader device. In one embodiment, the user may input the headphone identifier and, optionally, information regarding which side of the headphones the audio controller is connected to into a computer. The computer can access data storage that stores factory calibration data associated with a particular headphone identifier. The computer can receive the factory calibration settings in response to the identifier being sent to the data storage. The stored factory calibrations include factory calibration information for both the left and right sides of the headphones. The audio controller has information regarding which side of the headphones it is connected to. The audio controller can correctly apply the factory calibration to both sides of the headphones.

[0033] Passive headphones may be changed or replaced with new ones while using the same audio controller. In such cases, the new passive headphones are connected to the (already used) audio controller. The factory calibration settings for the new passive headphones are obtained using an identifier such as the serial number of these new passive headphones. The computer that receives the factory calibration settings sends them to the audio controller for use in signal processing for the new passive headphones. In this way, passive headphones can be changed and / or replaced using the individual factory calibrations of each passive headphone while keeping the same audio controller, and the resulting headphone sound quality can remain the same, accurate, and neutral. Furthermore, multiple passive headphones can be used with a single audio controller, provided that only one pair of headphones is used at a time. For example, in a certain work environment, one audio controller can be used by multiple different passive headphones and their users at different times.

[0034] Figure 2 shows an example of an audio controller. The audio controller includes input and output ports, which are configured to input and output audio data, respectively. The audio controller may include input ports for left (L) and right (R) analog audio data, and similarly, output ports for left (L) and right (R) analog audio data. The audio controller may also include input and output (I / O) ports for digital audio data. For example, the audio controller may include an input and output (I / O) port for headphones, a Universal Serial Bus (USB) connection port, or other connection ports such as a cable port, AUX port, HDMI port, or coaxial port. The audio controller includes a battery, a user interface (UI), and a signal processor (SP). The audio controller may also include an amplifier (Amp), which may be a headphone amplifier integrated into the audio controller. The amplifier can amplify current, voltage, or power. An amplifier may be a power amplifier configured to convert a low-power signal into a high-power signal by increasing the input power. Power amplifiers are sometimes called high-signal amplifiers and are configured to supply a large amount of power to the input audio signal. Power amplifiers can supply more power to the output but tend to be larger and heavier than non-power amplifiers. However, size and weight do not affect the size or weight of passive headphones, although this is a greater issue for active headphones with an integrated audio controller. Furthermore, an audio controller may comprise one or more transducers and a digital-to-analog converter (DAC). The audio controller is configured to control the audio data.

[0035] The audio controller may be a mobile or portable audio controller. Mobile audio controllers differ in size from desktop audio controllers; desktop audio controllers are fixed in one location, such as a studio, while mobile audio controllers are portable and smaller and lighter than desktop audio controllers. Mobile audio controllers may have fewer functions and adjustment capabilities compared to desktop models. Desktop audio controllers are powered from commercial power via a connected outlet, while mobile audio controllers can operate using commercial power in addition to a rechargeable battery or AC power.

[0036] The audio controller may be connected to the passive headphones, for example, via an I / O port. The audio controller may be connected to a computer via a USB port. Both of these connections may be wired cable connections. Wired connections avoid lag or other problems that may occur due to wireless networks, which may be caused by location and / or the network used. The audio controller is configured to receive factory calibration settings that have been measured and stored for a particular pair of passive headphones. Factory calibration settings may be stored in the audio controller and / or received from a computer. The audio controller is configured to use the factory calibration settings for any input to the passive headphones.

[0037] Audio signals can be represented in digital or analog formats, and the processing of audio signals may be based on one of these. Analog signal processors can act directly on electrical signals, while digital signal processors act mathematically on the digital representation of electrical signals. Audio controllers can be used to balance and adjust sound sources. Audio controllers may include equalizers (EQ) and / or processors configured to process sound dynamics, audio effects, mixing, playback, and enhancement. Equalization (EQ) involves the step of adjusting the volume of several different frequencies within an audio signal. Audio filters may include frequency-dependent circuits that can amplify (boost), pass through, or attenuate (cut) selected frequencies or frequency ranges. Compression, or dynamic range compression (DRC), is configured to narrow or compress the dynamic range of an audio signal by reducing the volume of loud sounds or amplifying quiet sounds. Compression can be implemented by a compressor, which may be a dedicated electrical hardware unit or audio software.

[0038] The audio controller includes equipment or signal processing functions for amplifying, controlling, and processing audio signals sent to passive headphones, and for setting processing variables or parameters that affect the audio signals. A computer can deliver, download, or stream audio data to the headphones via the audio controller. The audio controller may include inputs that allow audio signals to be sent directly to the audio controller for processing and sending to the headphones. The audio controller can adjust the input electrical signals to provide sound through passive headphones.

[0039] Figure 4 shows a computer as an example. The computer includes a processor, which may be the computer's central processing unit. 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 memory units, which may include, for example, read-only memory (ROM), random access memory (RAM), and flash memory. The memory (MEM) may include executable instructions, which are executable by the processor. The memory is configured to store information, executable instructions, and at least one application configured to communicate with an audio controller. The computer includes a battery and a user interface. The user interface may include input / output means for the user, such as a display, keys, and a touchscreen. The computer includes physical ports for wired connections. These ports include input / output (I / O) ports and a Universal Serial Bus (USB) port. The computer may also include other ports for connecting to external devices and / or terminals. The computer comprises a transmission branch (TX) and a receiving branch (RX). The transmission and receiving branches (TX / RX) may include a receiver / transmitter, a digital-to-analog converter, an analog-to-digital converter, an amplifier, and an antenna. The transmission 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. The wireless connection may be a radio frequency network, a cellular network, or a communication network capable of enabling the exchange of data and information. Furthermore, the computer may include transmitting means configured for short-range wireless communication, such as Bluetooth or infrared.The computer may be connected to the internet via a modem, and the modem may be connected via cable or a wireless connection such as Wi-Fi compliant with the IEEE 802.11 standard (Institute of Electrical and Electronics Engineers).

[0040] The computer may include a mobile computer, mobile device, handheld computer, smartphone, desktop computer, laptop, tablet, or any suitable device. The computer may include means for obtaining factory calibration settings in response to the reception of a passive headphone identifier, and means for communicating these factory calibration settings to an audio controller. The computer may include a software application configured to communicate with the audio controller. This application can provide a user interface for receiving input from the user and outputting information to the user.

[0041] Figure 4 shows an example of a method for calibrating passive headphones. The passive headphones are connected to an audio controller. The method includes the step (401) of acquiring factory calibration data by the audio controller. The factory calibration data is specific to the passive headphones and is associated with the identifier of the passive headphones. The method further includes the step (402) of applying the factory calibration data to the electrical signal input to the passive headphones by the audio controller. The method may include the steps of amplifying the electrical signal transmitted to one or more transducers of the passive headphones by a headphone amplifier integrated into the audio controller, and reproducing the electrical signal as sound by the passive headphones. The method may include the step of pre-storing the factory calibration data in the audio controller paired with the passive headphones and in remote storage. The method may include the step of applying a factory calibration configured by the audio controller to adjust the frequency response of the passive headphones. The method may include the step of receiving the factory calibration from a computer. The computer may be configured to access remote storage to receive factory calibration in response to the provision of an identifier for passive headphones. The above method may include the step of the audio controller automatically receiving the identifier in response to connection to the passive headphones and / or via short-range signaling from the passive headphones. The above method may include the step of the computer receiving the identifier via short-range signaling and / or the computer receiving the identifier from the audio controller. The above method may include the step of the audio controller automatically receiving information about the side of the passive headphones to which the audio controller is connected via a connecting cable between the audio controller and the passive headphones and / or via short-range signaling when the passive headphones are connected to the audio controller.

[0042] In the above description and diagrams, the passive headphones become active when connected to the audio controller, which can further obtain the factory calibration settings for this particular passive headphone via a computer. The system is modular, allowing one of the passive headphones, audio controller, or computer to be changed or replaced at a time. For example, replacing the passive headphones does not affect the other audio controller and computer modules, and the system with the new passive headphones can be connected, calibrated, and used with the same precision and quality as the passive headphones before replacement.

[0043] The computer can receive or download audio data for listening via passive headphones. The audio data is transmitted via the computer to an audio controller. The audio controller is configured to process, calibrate, and / or equalize the audio data. Audio signal processing, or all audio signal processing, is implemented in the audio controller. No further computing or transmitting power is required from the computer.

[0044] The Head-Related Transfer Function (HRTF) is used to provide headphone users with a three-dimensional (3D) audio experience. The HRTF can create a 3D model of the user using images of the user's head, torso, and / or outer ear. The HRTF describes an acoustic filter that quantifies the influence of the head, torso, and outer ear shapes on sound reaching the entrance of the ear canal. A baseline HRTF can be prepared, for example, using speakers in a listening room. Using the HRTF, each passive headphone can be matched to a predetermined auditory experience, for example, multiple speakers in a listening room. This allows the response of passive headphones to correspond to the acoustic simulation of the room. Factory calibration settings ensure a certain acceptable range of passive headphone quality. Using an individual HRTF after factory calibration provides a personalized 3D audio experience. This enables a high-quality, user-specific audio experience. Without factory calibration settings, variations between individual headphones may lead to further variations and / or problems when using the HRTF.

[0045] Listeners can adjust their headphones. Headphones are factory calibrated to produce a natural or flat sound. The reproduced sound is predictable. After the factory-calibrated natural playback, listeners can select their headphone settings. For example, one listener might choose a so-called warm sound, boosting the bass frequencies, which are the low or mid-low frequencies. In a warm sound, low frequencies are dominant compared to higher frequencies. A warm sound is sometimes called "bass-heavy." The opposite of a warm sound is a so-called bright sound, where high frequencies are boosted. In a bright sound, high frequencies are dominant compared to lower frequencies. For most people, the audible spectrum is in the range of approximately 20Hz to 20kHz, which contains about 20,000 different frequencies. In a studio environment, the entire frequency spectrum of various elements such as instruments may be controlled, adjusted, and / or mixed. The frequency response of a signal represents the amount (volume) of all frequencies within the range of human hearing. The frequency response can be edited in various ways, for example, by equalization and filtering. Equalization is configured to modify multiple parts of the frequency response of a signal. Filtering is configured to attenuate parts of the audio spectrum. Audio mixing refers to the process of optimizing multi-track recordings and combining them into a final sound product. Mixing may include steps to adjust the individual tracks of a multi-track recording to balance their relative levels, and this may include equalization and compression. The system described herein, comprising an audio controller, passive headphones, and a computer, can be a substitute for a mixer, sometimes called a mixing console, mixing desk, mixing board, or software mixer. Mixing can be implemented by software or applications downloaded or added to a computer and an audio controller configured to handle signal processing.While mixing consoles can be large and feature a vast number of controls, the system presented in this application provides a mobile system for mixing. Although the number of controls in the system described herein may not be as extensive as those in larger, stationary, localized mixers, its mobility enables instantaneous mixing anywhere.

[0046] It should be understood that embodiments of the inventions disclosed herein are not limited to any specific structure, process step, or material disclosed herein, but extend to equivalents thereof as recognized by a person of ordinary skill in the relevant art. It should also be understood that the terminology used herein is for the sole purpose of describing specific embodiments and is not intended to be limiting.

[0047] The features, structures, or properties described herein can be combined in any suitable manner in one or more embodiments. The above description provides numerous specific details, such as examples of structure, length, width, shape, etc., to provide a complete understanding of embodiments of the present invention. However, a person familiar with the relevant art will recognize that the present invention can also be carried out without using one or more of these specific details, or using other methods, components, materials, etc. In other examples, well-known structures, materials, or operations are not illustrated or described in detail to avoid obscuring aspects of the present invention.

[0048] While the embodiments described above illustrate the principles of the present invention in one or more specific applications, it will be apparent to those skilled in the art that numerous modifications can be made to the form, usage, and implementation details without demonstrating inventive ability and without departing from the principles and concepts of the present invention. Therefore, the present invention is not intended to be limited except as defined by the claims set forth below.

[0049] The verbs "to comprise" and "to include" are used in this document as non-restrictive limitations that neither exclude nor require the existence of features not described. Features described in dependent claims can be freely combined with each other unless otherwise specified. Furthermore, throughout this document, the use of "a" or "an," i.e., the singular form, should be understood as not excluding the plural. [Explanation of Symbols]

[0050] 101 Passive Headphones 102 Audio Controller 103 Computer 104 storage

Claims

1. A system comprising passive headphones (101) and an audio controller (102), - The passive headphones (101) are connected to the audio controller (102), - The audio controller (102) is configured to acquire factory calibration data that is specific to the passive headphones (101) and associated with the identifier of the passive headphones (101), - Factory calibration data is pre-stored in the audio controller paired with the passive headphones (101) and in remote storage, and the pre-stored factory calibration data includes factory calibration data for both the left and right sides of the passive headphones (101). - If the identifier of the passive headphones (101) connected to the audio controller is not paired with the audio controller, the audio controller is configured to receive a factory calibration via the computer in response to the identifier of the passive headphones (101) being transmitted to the computer; - The audio controller (102) is configured to apply the factory calibration data to the electrical signal input to the passive headphones (101), in a system.

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

3. The system according to claim 1 or 2, wherein the identifier is exclusive to the passive headphones (101); and / or the identifier is a serial number, component, memory chip, transponder, electronic tag, or radio frequency identification tag, i.e., an RFID tag.

4. The system according to any one of claims 1 to 3, wherein the identifier is attached to the passive headphones (101), associated with the passive headphones (101), and / or available within or together with the passive headphones (101).

5. The system according to any one of claims 1 to 4, wherein the audio controller (102) comprises an integrated headphone amplifier, the headphones (101) comprises one or more transducers, and the headphone amplifier is configured to amplify the electrical signals transmitted to the one or more transducers of the passive headphones (101) which are configured to reproduce the electrical signals as sound outputs.

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

7. The factory calibration of the system according to any one of claims 1 to 6, comprising, optionally, at least one of the following parameters measured on both sides of the passive headphones (101): impedance, sensitivity, level of acoustic output as a response to an electrical input, and phase, across the entire frequency range.

8. The system according to any one of claims 1 to 7, wherein the factory calibration 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, wherein the computer (103) is configured to be connected to the audio controller (102), and the audio controller (102) is configured to receive the factory calibration data from the computer (103), which is configured to access the remote storage (104) to receive the factory calibration stored in the remote storage (104) in response to the identifier of the passive headphones (101) provided.

10. The system according to any one of claims 1 to 9, wherein the identifier of the passive headphones (101) is automatically received by the audio controller (102) in response to the audio controller (102) being connected to the passive headphones (101) and / or via short-range signal transmission from the passive headphones (101).

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

12. The system according to any one of claims 1 to 11, wherein information regarding the side of the passive headphones (101) to which the audio controller (102) is connected is automatically received by the audio controller (102) via a connecting cable between the passive headphones (101) and the audio controller (102) and / or via short-range signal transmission when the passive headphones (101) are connected to the audio controller (102).

13. The system according to any one of claims 1 to 12, wherein the audio controller (102) is connected to the passive headphones (101) via a wired connection; and / or, according to claim 8, 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, wherein the computer (103) comprises at least a processor and memory containing instructions that the processor can execute, and the computer (103) is configured to access the remote storage (104).

15. A method for calibrating passive headphones connected to an audio controller, wherein the method is: - A step (401) in which the audio controller obtains factory calibration data that 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 paired with the passive headphones (101) and in remote storage, and the pre-stored factory calibration data includes factory calibration data for both the left and right sides of the passive headphones (101), step (401), - If the identifier of the passive headphones (101) connected to the audio controller is not paired with the audio controller, the audio controller receives a factory calibration via the computer in response to the identifier of the passive headphones (101) being transmitted to the computer, and - Step (402) of applying the factory calibration data to the electrical signal input to the passive headphones using the audio controller. Methods that include...

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