System and method for daisy chain addressing in speaker system

Abstract

To provide a speaker system with built-in arrangement for self-testing and a method for testing the speaker system.SOLUTION: A speaker system 100 comprises: a main unit 101 for generating a control voltage, a reference voltage, and an audio signal to a plurality of passive units 102; the plurality of passive units 102 connected by at least a control voltage signal connection 110, a reference voltage signal connection 111 and an audio signal connection 112 to form a daisy chain; and a voltage regulation unit 120 for providing a local reference voltage to each passive unit. Each passive unit comprises: a speaker 113; a voltage threshold generator 116 for generating a voltage threshold from the local reference voltage; a comparator 115 for comparing the control voltage with the voltage threshold to an audio enabling signal for enabling reproduction of the audio signal using the speaker 113; and a logic gate 114 for processing comparator digital output.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] SUMMARY The present disclosure relates to a speaker system with built-in mechanisms for self-testing and a method for testing a speaker system. [Background technology]

[0002] In electronics, daisy chaining refers to the practice of connecting devices or components in series one after the other using a single wire or connection. This is common, for example, in power supply configurations where multiple devices are powered in sequence from a single source. Each device in the chain is connected in series to the device before and after it, forming a chain-like structure.

[0003] Daisy chains are commonly used in many different fields, such as data communications, control systems, LED lighting systems, or audio systems. Specifically, in passive speaker systems, multiple speakers can be connected in series. Some systems require multiple speakers to spread the same sound or information to different locations while covering a large area.

[0004] An efficient strategy for deploying a network of multiple speakers throughout a room or relatively large area involves connecting one main unit to the network and providing power and audio signals to a daisy chain of passive speakers. This approach can minimize the overall length or amount of cable used in the network. A typical cabling solution for a speaker system can include, for example, the use of Ethernet cables, which are generally a cost-effective option for networked speaker systems.

[0005] While the above-described system is simple and cost-effective in itself, it can make individual testing of the speakers more difficult. Ideally, the passive speakers in a daisy chain of passive speakers should be as simple as possible to keep the bill of materials to a minimum. However, keeping the passive speakers as simple as possible can impact the performance of individual testing of the speakers. For example, if a passive speaker does not have a local processing unit to control and / or perform testing, individual testing becomes extremely difficult.

[0006] U.S. Patent Application Publication No. 2019 / 356986 discloses an impedance matching device including a transformer having an input side and an output side, the input side including a first coil having a first impedance, a second coil having a second impedance, and a third coil having a third impedance. An input power connector is electrically connected to the input side of the transformer, and a pass-through output power connector is electrically connected to the input side of the transformer, the pass-through output connector also being electrically connected in parallel with the input power connector. A speaker output connector having four electrical contacts is included, a first pair of the four electrical contacts electrically connected to the first coil, and a second pair of the four electrical contacts electrically connected to the second coil. Summary of the Invention

[0007] The present disclosure relates to a speaker system with a built-in mechanism for self-testing and a method for testing a speaker system. The disclosed system and method address the challenge of testing speakers individually through an arrangement in which each of several connected passive speakers can be individually enabled using control voltage signal connections and reference voltage signal connections.

[0008] The speaker system includes a main unit and a plurality of passive units, the main unit and the plurality of passive units being connected to form a daisy chain by at least a control voltage signal connection, a reference voltage signal connection, and an audio signal connection. The speaker system includes a main unit and a plurality of passive units, and is configured to test the plurality of passive units individually, the main unit and the plurality of passive units being connected to form a daisy chain by at least a control voltage signal connection, a reference voltage signal connection, and an audio signal connection. The main unit is a control voltage to the plurality of passive units via a control voltage signal connection; a reference voltage to the plurality of passive units via a reference voltage signal connection; and Audio signal to multiple passive units via audio signal connections the loudspeaker system further comprising a voltage regulation unit between each of the plurality of passive units on the reference voltage signal connection, each voltage regulation unit adapted to provide a local reference voltage to each passive unit, the local reference voltages to the plurality of passive units gradually increasing or decreasing between successive passive units along the daisy chain; Each of the plurality of passive units A speaker unit, a comparator unit configured to compare the control voltage with a first voltage threshold and a second voltage threshold generated from a local reference voltage, and to generate an audio enable signal that enables playback of an audio signal by the speaker unit when the control voltage is between the first voltage threshold and the second voltage threshold; Equipped with The main unit receives feedback from each of the passive units.

[0009] The term "daisy chain" should be interpreted broadly to encompass a configuration in which a cable is connected from a main unit to passive units by one or more overall connections or cables, but the passive units may have local parallel branches from the one or more overall connections or cables. Technically, this means that a daisy chain may include parallel components. To explain the concepts and terminology in this regard, reference can be made to FIGS. 1 and 2. In FIG. 1, a main unit 101 and multiple passive units 102 form a daisy chain. An audio signal connection 103 connects the main unit 101 and multiple passive units 102 in the daisy chain. However, in FIG. 2, it can be seen that an audio signal connection 112 may have a parallel connection to all of the passive units 102. The term "daisy chain" should be interpreted broadly to encompass such a configuration. the main unit is configured to generate a control voltage to the plurality of passive units via the control voltage signal connection, a reference voltage to the plurality of passive units via the reference voltage signal connection, and an audio signal to the plurality of passive units via the audio signal connection; the speaker system further comprising a voltage adjustment unit between each of the plurality of passive units on the reference voltage signal connection, the voltage adjustment unit being one or more resistors, each voltage adjustment unit being adapted to provide a local reference voltage to each passive unit, the local reference voltage to the plurality of passive units gradually increasing or decreasing among successive passive units along the daisy chain; each of the plurality of passive units comprising a speaker unit and a comparator unit configured to compare the control voltage with a first voltage threshold and a second voltage threshold generated from the local reference voltage, and to generate an audio enable signal that enables playback of the audio signal by the speaker unit when the control voltage is between the first voltage threshold and the second voltage threshold.

[0010] Each of the plurality of passive units may include a comparator unit configured to compare the control voltage with first and second voltage thresholds generated from a local reference voltage. By having a reference voltage that increases or decreases along the chain of passive units, each passive unit has its own unique local reference voltage. The local reference voltage and the control voltage may be used to individually enable the speaker units within the passive unit. An audio enable signal may be enabled in each of the plurality of passive units by using two connections, namely, a control voltage signal connection and a reference voltage signal connection. The number of connections for generating the audio enable signal in the passive unit, which in the above case is two connections or two signals, may be independent of the number of passive units in the plurality of passive units, which may be at least two, preferably at least five, more preferably at least ten, and even more preferably at least twenty passive units.

[0011] By using the speaker system of the present disclosure, certain expensive and / or complex components, such as processing units, can be omitted from passive speakers while maintaining the possibility of testing the speakers individually. Advantageously, a main unit can handle the majority of the functionality, which can be provided to multiple passive units simply by using control voltage signal connections, reference voltage signal connections, and audio signal connections.

[0012] The present disclosure further relates to a method for testing a speaker system comprising a main unit and a plurality of passive units connected to form a daisy chain by at least a control voltage signal connection, a reference voltage signal connection, and an audio signal connection, the method including: providing a local reference voltage to each passive unit by generating a reference voltage on the reference voltage signal connection that gradually increases or decreases between successive passive units along the daisy chain; providing a control voltage on the control voltage signal connection; generating audio signals to the plurality of passive units via the audio signal connections; at each passive unit, comparing the control voltage with first and second voltage thresholds generated from the local reference voltage, and generating an audio enable signal that enables playback of the audio signal by the speaker unit of the passive unit when the control voltage is between the first and second voltage thresholds; and testing each passive unit by receiving feedback from each passive unit.

[0013] The method may provide a method for testing a speaker system, the speaker system including a main unit and a plurality of passive units. Using one reference voltage and one control voltage, the speaker system can individually enable a speaker in each of the plurality of passive units, and the reference voltage can be used to generate a local reference voltage for each passive unit. Each of the plurality of passive units can be tested by playing an audio signal through the speaker. The audio signal played by the speaker can be recorded by the main unit via a microphone. An alternative test can be performed by measuring or monitoring a supply current derived from a supply voltage, which is provided to the plurality of passive units by the main unit. As soon as an audio signal is played through the speaker of one of the plurality of passive units, the supply current can be monitored via the supply voltage connection, thereby testing the speaker of one of the plurality of passive units.

[0014] A speaker system may be configured so that only one passive unit plays an audio signal at a time. This can be used to test whether a particular speaker unit is functional. This can be achieved by the method described herein, in which a main unit can provide a sweeping control voltage over a control voltage connection that addresses a particular passive unit connected in a daisy chain by comparing the control voltage to first and second voltage thresholds.

[0015] By gradually increasing or decreasing the reference voltage, a local reference voltage is provided to each of the passive units. The main unit can provide a control voltage over the control voltage signal connection, such as a pulse width modulated (PWM) control voltage signal that can be configured to enable or disable specific passive units in the daisy chain.

[0016] Various embodiments are described below with reference to the drawings, which are non-limiting examples of embodiments and are intended to illustrate some of the features of the speaker systems and methods of testing speaker systems of the present disclosure. [Brief explanation of the drawings]

[0017] [Figure 1] 1 shows a schematic diagram of one embodiment of a speaker system disclosed herein. [Figure 2] 1 shows a schematic diagram of one embodiment of a speaker system disclosed herein, showing a schematic diagram of multiple passive units. [Figure 3] 1 shows a schematic diagram of one embodiment of multiple passive units, with electrical connections shown. [Figure 4] 1 illustrates an example of triggering of a control voltage and enable signal swept from a first level to a second level in a passive unit. [Figure 5] 1 shows a schematic diagram of one embodiment of eight conductors included in an Ethernet cable connecting a main unit to a passive unit in series. DETAILED DESCRIPTION OF THE INVENTION

[0018] The present disclosure relates to a speaker system comprising a main unit and a plurality of passive units, the main unit and the plurality of passive units being connected by at least a control voltage signal connection, a reference voltage signal connection, and an audio signal connection, the main unit being configured to generate a control voltage via the control voltage signal connection, a reference voltage via the reference voltage signal connection, and an audio signal via the audio signal connection, the speaker system further comprising a voltage adjustment unit between each of the plurality of passive units on the reference voltage signal connection, each voltage adjustment unit being adapted to provide a local reference voltage to each passive unit, the local reference voltage to the plurality of passive units increasing or decreasing between successive passive units, each of the plurality of passive units comprising a speaker and a comparator configured to compare the control voltage with first and second voltage thresholds generated from the local reference voltages, and to generate an audio enable signal that enables playback of the audio signal by the speaker when the control voltage is between the first and second voltage thresholds.

[0019] FIG. 1 shows a schematic diagram of one embodiment of a speaker system 100. The speaker system 100 includes a main unit 101 and multiple passive units 102 connected by at least a control voltage signal connection, a reference voltage signal connection, and an audio signal connection 103 to form a daisy chain. Each passive unit 102 includes a speaker unit 104 and a comparator unit 105. FIG. 1 shows the main unit 101 and four passive units 102. Additional passive units may be connected after the fourth passive unit. All passive units include a speaker unit 104 and a comparator unit 105. By connecting the main unit and passive units in a daisy chain arrangement, reduced complexity of the speaker system is achieved. Using a daisy chain configuration can be cost-effective because less cabling is required, reducing the need for additional equipment. It should be noted that the term "daisy chain" may be broadly interpreted to encompass a configuration in which cables are connected from a main unit to passive units by one or more overall connections or cables, but the passive units have local parallel branches from the one or more overall connections or cables. Technically, this means that a daisy chain may include parallel components. Adding additional passive units is easier, as a user can easily connect at least one additional passive unit to an existing chain without significant modifications. Having a main unit allows for centralized control.

[0020] In one embodiment, the voltage regulation unit includes a resistor. The resistor may be a fixed resistor, a variable resistor such as a rheostat or potentiometer, and / or a specialized resistor such as a thermistor or varistor. Preferably, a fixed resistor can be used to keep the system simple while limiting the cost of any potentially more expensive alternatives. The voltage regulation unit may include a voltage drop device configured to create a voltage drop. The voltage drop device may be a diode such as a Zener diode, an LED, a transistor configured to generate a voltage drop, such as an NMOS or PMOS device, or any other suitable element or component for generating a voltage drop. Bipolar junction transistors may also be used according to the same principle; in the case of an NPN, the collector junction is shorted with the base junction. Inductors may also have a series resistor that can be used to generate a voltage drop, and therefore can also be used as a voltage drop device. Interconnects such as cables and / or copper wiring may have a series resistor. In this case, interconnects that can connect the main unit to multiple passive units can also be used to generate a voltage drop.

[0021] Alternatively, the speaker system may be designed so that the reference voltage increases along the chain of passive units. This can be achieved by a higher voltage at one end of the chain and a voltage drop at the other end of the chain. In theory, the voltage regulation unit could even comprise a voltage step-up unit. The voltage step-up unit could comprise a DC-DC converter, such as a boost converter, and / or a charge pump, such as a switched-capacitor DC-DC converter.

[0022] In a preferred embodiment, the voltage regulation unit includes a resistor. The resistor can have a resistance between 1 kΩ and 1 MΩ, such as between 1 kΩ and 500 kΩ, or between 1 kΩ and 100 kΩ, or between 1 kΩ and 80 kΩ, or between 1 kΩ and 50 kΩ, or between 1 kΩ and 40 kΩ, or between 1 kΩ and 30 kΩ, or between 1 kΩ and 20 kΩ, or between 1 kΩ and 10 kΩ, or between 1 kΩ and 5 kΩ, or between 1 kΩ and 2 kΩ. A typical value for a resistor useful for this purpose is 10 kΩ. A higher resistance value may result in a larger voltage drop, making the speaker system difficult to use. A lower resistance value may result in a smaller voltage drop. A compromise can be found by considering the typical impedances of the various nodes in the speaker system. Some nodes may have low or high impedance, and the resistor values ​​may be selected accordingly to keep current leakage through the nodes to a minimum while allowing a relatively large voltage drop between each of the multiple passive units.

[0023] A speaker system can include at least two, or at least five, or at least ten, or even at least twenty passive units. Each passive unit can be connected to form a daisy chain. A daisy chain can refer to a wiring or connection configuration in which devices are connected one after the other in series, preferably in a linear manner. This term can be used to describe a method of interconnecting devices or components in a manner that forms a chain-like structure. In the present disclosure, a main unit and multiple passive units can be connected to form a daisy chain. All connections, such as control voltage signal connections, reference voltage signal connections, and audio signal connections, can be included in an interconnection cable, which is used to interconnect or connect the main unit and multiple passive units.

[0024] In one embodiment, the first voltage threshold and / or the second voltage threshold are between 0 V and a local reference voltage. The first voltage threshold and / or the second voltage threshold may be generated from the local reference voltage. The first voltage threshold and / or the second voltage threshold may be generated by applying a voltage transformation to the local reference voltage, where the voltage transformation may be a voltage drop or a voltage increase.

[0025] In one embodiment, the plurality of passive units include first and second voltage threshold generators. The first and second voltage threshold generators may be configured to generate the first and second voltage thresholds. Preferably, the first and second voltage threshold generators may be configured to generate the first and second voltage thresholds from a local reference voltage. The local reference voltage may be an input to the first and second voltage threshold generators. The first and second voltage threshold generators may include at least one passive device and / or at least one active device.

[0026] Each passive unit may be configured to generate the first and / or second voltage thresholds by voltage division. The voltage division may be performed by a voltage divider. Voltage division, as generally known to those skilled in the art, is a common technique used in electronic devices to distribute voltages across multiple resistors, preferably in a series circuit, by a voltage divider.

[0027] In a preferred embodiment, the voltage divider includes two voltage divider resistors arranged in series between the local reference voltage and ground. Each of the two voltage divider resistors may have a voltage divider resistance, which may be selected so that a useful first or second voltage threshold is provided by the voltage division. The first voltage threshold may be lower than the second voltage threshold, although in principle, the opposite would also work. Using a voltage divider with two voltage divider resistors provides an inexpensive and simple solution for generating the first and / or second voltage thresholds from the local reference voltage. As previously mentioned, a low resistance value of the voltage divider may result in unnecessary current leakage from the local reference voltage and ground, while a resistance value of the voltage divider that is too high may result in a small voltage drop between each of the multiple passive units for a given resistance value of the resistors included in the voltage regulation unit. To avoid the need to determine a compromise, an impedance buffer may be included in the voltage regulation unit. The impedance buffer may be a buffer amplifier. The buffer amplifier may be used to provide high and low input impedances. This can isolate or separate one part of a circuit from another and prevent loading effects. Some common types of impedance buffers can include: Operational Amplifier (Op-Amp) Buffer: The use of an operational amplifier configured in voltage follower (gain of 1) mode creates a buffer with high input impedance and low output impedance. Emitter-follower buffer: A transistor configured as an emitter follower provides a buffer with low output impedance and a voltage gain of unity. · Source follower buffer: A transistor configured as a source follower (common drain) provides a buffer with low output impedance and a voltage gain of unity. · Voltage follower buffer: A simple voltage follower circuit using an amplifier with a gain of 1, such as an operational amplifier, acts as an impedance buffer. FET (Field Effect Transistor) Buffer: A FET configured as a source follower can act as a buffer and provide a low output impedance. Transformer-based buffers: Transformers can be used to create impedance buffers, especially in audio applications. Primary and secondary windings provide isolation and impedance matching.

[0028] The comparator unit may include at least two comparators, where a first comparator may be configured to compare a first voltage threshold with the control voltage and a second comparator is configured to compare a second voltage threshold with the control voltage. By having two comparators that compare the first and second voltage thresholds with the control voltage, a voltage window can be defined, and thus a voltage range in which the control voltage is higher than the first voltage threshold and lower than the second voltage threshold (or vice versa if the second voltage threshold is lower than the first voltage threshold) can be identified.

[0029] The first comparator can generate a first comparator digital output, and the second comparator can generate a second comparator digital output. The first and second comparator digital outputs can then be used to define a voltage range as described above, and the digital outputs can be further used in digital circuitry.

[0030] The first comparator digital output and the second comparator digital output may be input to a logic gate. By using the first and second comparator digital outputs as inputs to the logic gate, a digital decision can be made by the logic gate depending on the outputs of the two comparators. The digital decision may be true if the control voltage is between the first and second voltage thresholds and may be false if the control voltage is not between the first and second voltage thresholds.

[0031] In one embodiment, the logic gate is configured to output an audio enable signal depending on the input. The audio enable signal may depend on a digital decision as described in the preceding paragraph. The digital decision may depend on the input. The audio enable signal may be used to activate an amplifier that can be used to play the audio signal on a speaker.

[0032] The logic gate may be an XOR gate or an AND gate. The logic gate may be selected so that an accurate digital decision is obtained as the output of the logic gate. An AND gate may be accurate if the control voltage is between the first and second voltage thresholds when both comparators output a high digital output. An XOR gate may be accurate if the control voltage is between the first and second voltage thresholds when one comparator outputs a high digital output and the other comparator outputs a low digital output.

[0033] FIG. 2 shows a schematic diagram of one embodiment of a speaker system 100 disclosed herein, illustrating a plurality of passive units 102. Each of the plurality of passive units includes first and second voltage threshold generators 116, two comparators 115, a logic gate 114, and a speaker 113. The speaker may be a speaker unit described herein. The speaker unit may include a speaker amplifier and / or any other auxiliary device or system that can be used in combination with a speaker or an acoustic radiating device. The main unit is configured to generate control voltages to the plurality of passive units via a control voltage connection 110, audio signals to the plurality of passive units via an audio signal connection 112, and reference voltages to the plurality of passive units via a reference voltage connection 111. A voltage adjustment unit 120 is disposed between each of the plurality of passive units on the reference voltage signal connection 111. The voltage regulation unit 120 is adapted to provide a local reference voltage to each passive unit. A voltage difference can exist across the voltage regulation unit 120, causing the reference voltage to decrease or increase along the reference voltage signal connection in the chain of passive units 120. A user can configure the voltage regulation unit to gradually increase or decrease the reference voltage between successive passive units along the daisy chain. By gradually increasing or decreasing the reference voltage, at least one local reference voltage can be generated, thereby generating a unique local reference voltage for each of the multiple passive units. The speaker 113 receives an audio signal from the audio signal connection 112. The first and second voltage threshold generators 116 are configured to generate first and second voltage thresholds from the local reference voltage provided by the reference voltage signal connection 111. Each passive unit has its own local reference voltage and therefore its own first and second voltage thresholds. Two comparators 115 are disposed in the plurality of passive units, the comparators being configured to compare first and second voltage thresholds with a control voltage, which is provided by a control voltage signal connection 110 .The first comparator generates a first comparator digital output, and the second comparator generates a second comparator digital output. The first and second comparator digital outputs are processed in a logic gate, which outputs an audio enable signal that enables the speaker 113. Preferably, the logic gate is selected so that the audio enable signal is activated, or at a high logic level, when the control voltage is between the first and second threshold signals. The high logic level or high logic state can represent the binary value of 1 in the binary system and indicate a high digital voltage level or true logic state. The high logic level or low logic level represents a binary state used in digital electronics, with high and low voltages corresponding to logic 1 and 0, respectively. By enabling the speaker 113, the audio signal provided by the audio signal connection 112 can be played by the speaker 113 and thus heard by a user or a sound capture device. The sound capture device may be included in either the passive unit, the main unit, or a secondary system, preferably at a distance from the speaker that allows it to capture the sound emitted by the speaker.

[0034] FIG. 3 shows a schematic diagram of one embodiment of multiple passive units, illustrating an electrical overview. In this example, each passive unit includes first and second voltage threshold generators 116, where the first and second voltage thresholds are generated by a voltage divider, each of which includes two resistors. The resistance values ​​of the two resistors are selected so that the first and second voltage thresholds are different voltages. The voltage adjustment unit 120 is a resistor. By placing a resistor in the reference voltage signal connection, a voltage drop can be created between each passive unit, thereby generating a different local reference voltage for each of the multiple passive units. The voltage drop between each passive unit depends on the resistance value of the resistor and the current flowing into the resistor from the reference voltage generator 301. The current flowing into the resistor depends on the resistance value of the resistor in combination with the resistors placed in the first and second voltage threshold generators 116. It may be advantageous to determine a resistance value sufficient to create a sufficient voltage drop across the local reference voltage while minimizing the amount of current supplied to the reference voltage signal connection 111. Those skilled in the art would generally know how to determine a ratio that would provide a sufficient voltage drop while minimizing the amount of current supplied to the reference voltage signal connection by the reference voltage generator 301. The reference voltage generator 301 may be located in the main unit. First and second voltage thresholds are generated from the local reference voltage generated from the reference voltage signal connection 111. The first and second voltage thresholds are then compared to control voltages in two comparators 115. The input connections of the two comparators are one specific embodiment, and the embodiment should not be limited to this specific embodiment described in FIG. 3. The two comparators output first and second comparator digital outputs. Pull-up and / or pull-down resistors are located at the first and second comparator digital outputs to ensure known states at the first and second comparator digital outputs. As described in connection with FIG. 2, the first and second comparator digital outputs are processed in logic gate 114, which outputs an audio enable signal that enables a speaker (not shown in FIG. 3).

[0035] FIG. 4 shows an example of a control voltage swept from a first level to a second level, triggering a local enable signal in each of four passive units. In this example, the first level is 0 V at the beginning of the process and the second level is 38 V at the end of the process. Those skilled in the art will understand that these two levels can be adjusted to suit the situation and the number of passive units. For one of the passive units, the first and second voltage thresholds are configured to be generated at 27 V and 29 V, respectively. The first and second voltage thresholds shown in FIG. 4 are generated by one of the passive units. As can be seen in FIG. 4, the local audio enable signal for the passive unit is set to a digital logic high when the control voltage is between the first and second voltage thresholds. As soon as the control voltage exceeds the first voltage threshold, the audio enable signal becomes a digital logic high, which is 5 V in this particular embodiment. As soon as the control voltage exceeds the second voltage threshold, the audio enable signal becomes a digital logic low, which in this particular embodiment is 0 V. By sweeping the control signal between the first and second voltage thresholds, or preferably setting the control signal between the first and second voltage thresholds, the audio enable signal can be activated for a particular passive unit having the first and second voltage thresholds, thereby enabling the speaker to play the sound provided by the audio signal connection. In the diagram of FIG. 4, it can be noted that the enable signal is activated four times: at 0.5 seconds, just after 1.0 seconds, between 1.5 and 2.0 seconds, and finally at 2.5 seconds. In this illustration, the four instances of the enable signal represent four different local enable signals in four different passive units.

[0036] The speaker system may further comprise a feed signal connection and / or a ground signal connection.

[0037] The main unit may be further configured to generate a feed signal to the plurality of passive signal units via a feed signal connection.

[0038] The supply signal may be a supply voltage, which may be comprised between 1.5 V and 120 V, for example between 1.5 V and 96 V, for example between 1.5 V and 48 V, for example between 1.5 V and 24 V, for example between 1.5 V and 12 V, for example between 1.5 V and 9 V, for example between 1.5 V and 5 V, for example between 1.5 V and 3.3 V. The supply voltage may be a standard supply voltage for Ethernet cables, such as a supply voltage comprised between 12 V and 57 V or between 37 V and 57 V.

[0039] The main unit may be further configured to generate a ground signal to the multiple passive signal units via a ground signal connection. The ground signal may be a ground voltage. The ground voltage may be, for example, 0V. In most practical electronic systems and electronic circuits or systems, the term "ground" may be used as a reference point and may conventionally be considered to be 0V. However, ground may also have a positive or negative voltage. Ground may also be referred to as a reference point to which all voltages used in the system are referenced.

[0040] The main unit and the plurality of passive units may be connected by at least five conductors configured to provide at least a supply signal connection, a ground signal connection, a reference signal connection, an audio signal connection, and a control signal connection.

[0041] The main unit and the multiple passive units can be connected by at least eight conductors. Having eight conductors allows for greater flexibility in the various connections described above, such as at least the control voltage signal connection, the reference voltage signal connection, the audio signal connection, the supply signal connection, and / or the ground signal connection. For example, two cables can be used for the supply signal connection and / or the ground signal connection.

[0042] An Ethernet cable may include at least five conductors or at least eight conductors. An Ethernet cable is a type of cable primarily used to connect devices within a local area network for the purpose of transmitting data. An Ethernet cable can also be used to transmit power. Ethernet cables are defined by standards established by the Institute of Electrical and Electronics Engineers (IEEE). Ethernet cables have connectors at each end, commonly known as RJ45 connectors. This allows for the promotion and cost reduction of systems compatible with such technology due to the widespread use and availability of this technology. Ethernet cables can also be used to implement Power over Ethernet (PoE). The speaker system of the present disclosure, which has built-in self-test configuration, can use an Ethernet cable to supply power but can operate without communicating via the PoE protocol. Power over Ethernet allows for the transmission of power over the same Ethernet cable used to interconnect devices or units via data communication. The choice of Ethernet cable category can be important in PoE applications. Higher categories such as Cat5, Cat5e, Cat6, Cat6a, or Cat7 are often preferred due to their high power transmission capabilities and low power loss over long cable lengths. When used in Power over Ethernet applications, Ethernet cables can provide a convenient and efficient way to power and connect devices in a network, reducing the need for additional power cables and simplifying installation in a variety of environments.

[0043] It is possible to provide the supply signal connection using a single conductor. In one embodiment, at least two conductors are configured to provide the supply signal connection. Having at least two conductors configured to provide the supply signal connection can reduce the supply voltage drop. Two parallel conductors can reduce the series resistance of the supply signal connection by a factor of two. More preferably, the series resistance of the supply signal connection can be further reduced by using three or more conductors in parallel. A compromise can be made to reduce the series resistance of the supply signal connection while minimizing the number of cables used for the supply signal connection.

[0044] In another embodiment, at least two conductors are configured to provide a ground signal connection. Having at least two conductors configured to provide a ground signal connection can reduce the supply voltage drop. Preferably, two conductors used in parallel can reduce the series resistance of the ground signal connection by a factor of two. More preferably, using three or more conductors in parallel can further reduce the series resistance of the ground signal connection. A compromise can be reached to minimize the number of cables used for the ground signal connection while reducing the series resistance of the ground signal connection. The inventors of the present invention have realized that at least two conductors can be used to reduce the series resistance of the ground signal connection to an acceptable level.

[0045] The audio signal connection may be a differential audio signal connection. Therefore, the audio signal may be a differential audio signal. In many applications or systems, differential audio signaling may be preferred over single-ended audio signaling due to several advantages related to noise rejection, common-mode rejection, and overall signal integrity. Differential signaling can help reject common-mode noise. Common-mode noise refers to interference present on both positive and negative signal lines in the same direction. In differential signaling, common-mode noise is canceled because the receiver responds only to the difference between the two signal lines. This increases the system's immunity to external noise sources. The common-mode rejection ratio (CMRR) is a measure of how effectively a system rejects common-mode signals. Differential signaling provides a high CMRR because common-mode noise is canceled. This is particularly important in environments with strong electromagnetic interference (EMI) or radio frequency interference (RFI). Differential signaling may be more suitable for longer cable lengths. In single-ended systems, long cables can act as antennas and pick up additional noise. The noise picked up by both signal lines is common-mode noise, which a differential receiver can effectively reject. Differential signaling can help maintain signal integrity by reducing the effects of external interference and noise. This can be preferable in high-fidelity audio applications, where maintaining the original signal quality is advantageous. In single-ended systems, ground loops can contribute to signal noise. Differential signaling helps minimize the effects of ground loops, as common-mode noise induced on the ground lines is rejected by the differential receiver. Differential signaling can enable an increased dynamic range in audio systems. This can accommodate a wider range of signal amplitudes without distortion, providing more headroom for the audio signal.

[0046] In one embodiment, the audio signal connection is configured to use at least two conductors, whereby a first conductor can provide the positive side of a differential audio signal while a second conductor can provide the negative side of the differential audio signal, thus providing a differential audio signal.

[0047] 5 shows a schematic diagram of one embodiment of eight conductors included in an Ethernet cable connecting main unit 101 to passive unit 102 in series. Main unit 101 is connected in series with passive unit 102 with eight conductors. Two of the eight conductors are configured to provide a supply signal connection 501, and two of the eight conductors are configured to provide a ground signal connection 502. Two of the eight conductors are configured to provide an audio signal connection 112. One of the eight conductors is configured to provide a control voltage signal connection 110, and another of the eight conductors is configured to provide a reference voltage signal connection 111.

[0048] The present disclosure further relates to a method for testing a speaker system that may include a main unit and a plurality of passive units, the main unit and the plurality of passive units being connected to form a daisy chain by at least a control voltage signal connection, a reference voltage signal connection, and an audio signal connection, the method may include providing a local reference voltage to each passive unit by generating a reference voltage on the reference voltage signal connection that gradually increases or decreases between successive passive units along the daisy chain; providing a control voltage on the control voltage signal connection; generating audio signals to the plurality of passive units via the audio signal connections; at each passive unit, comparing the control voltage with a first voltage threshold and a second voltage threshold generated from the local reference voltage, and generating an audio enable signal that enables playback of the audio signal by a speaker unit of the passive unit when the control voltage is between the first voltage threshold and the second voltage threshold; and testing each passive unit by receiving feedback from each passive unit.

[0049] In one embodiment, the feedback is received by the main unit. The main unit may include a secondary system that may be configured to process the feedback. The feedback may be processed by the secondary system such that information contained in the feedback enables the main unit to generate an action to be taken. Preferably, if the feedback provides information that one of the plurality of passive units may contain a fault, such as a non-functioning speaker, the main unit may generate a signal to inform a user that at least one passive unit of the plurality of passive units may require maintenance or replacement of at least one of the features contained in the at least one passive unit.

[0050] The feedback may be a feedback current. The main unit and the multiple passive units may be connected by a supply voltage connection. The supply voltage connection may generate a supply voltage. Thus, the feedback current may be a supply current driven by the supply voltage. Preferably, the main unit may generate power that can be supplied to the multiple passive units by the supply voltage connection. Conveniently, the supply current may be monitored or recorded by the main unit. By monitoring or recording the supply current provided at the supply voltage connection, detection of a fault in each of the multiple passive units may be detected. Conveniently, by generating an audio enable signal that enables a speaker unit in the passive unit to play an audio signal when the control voltage is between a first voltage threshold and a second voltage threshold, the resulting supply current may be measured or monitored by the main unit via the supply voltage connection. When an audio signal is played at the speaker unit and the speaker unit is functioning as expected, an AC signal reflecting the characteristics of the audio signal should be measured on the supply current. It should be noted that if the speaker unit is not functioning, an incorrect DC supply current may be measured, specifically a significant portion of the AC signal may be absent.

[0051] The feedback current may be a spike current caused by the activation of the speaker unit. By activating the speaker unit, the spike current following the activation of the speaker unit can be monitored, which may indicate that the speaker unit is functioning well.

[0052] The main unit and / or at least one of the multiple passive units may include at least one microphone. The main unit and / or at least one of the multiple passive units may include at least one audio capture device. The at least one microphone may be a condenser microphone, a dynamic microphone, or a ribbon microphone. A condenser microphone uses a diaphragm and a backplate to form a capacitor. Condenser microphones are known for their sensitivity and ability to capture a wide range of frequencies. Dynamic microphones use electromagnetic induction to generate an electrical signal. Dynamic microphones are known to be robust, versatile, and do not require an external power source. Ribbon microphones use a thin metal strip suspended in a magnetic field. Ribbon microphones are known for their smooth and natural sound reproduction. A dynamic microphone may represent a good option because it can generate captured sound without requiring external power, thus saving power.

[0053] In a preferred embodiment, the feedback is audio feedback, where the audio feedback is an audio signal played by the passive units and recorded by at least one microphone. As described herein, the detection of a fault in each of the multiple passive units can be detected by capturing and / or recording the audio feedback. The capturing and / or recording of the audio feedback can be performed using at least one microphone, which can be included in the main unit or at least one of the multiple passive units.

[0054] The method may further include sweeping a control voltage on the control voltage signal connection from a first voltage level to a second voltage level. By sweeping the control voltage on the control voltage signal connection from a first voltage level to a second voltage level, testing of multiple speakers of multiple passive units can be performed. Preferably, each of the multiple passive units can generate its own first and second voltage thresholds. By sweeping the control voltage, sequential activation of the speakers of consecutive passive units can be performed. A user can detect activation of the multiple speakers while sweeping the control voltage on the control voltage signal connection. The control voltage sweep may be a linear voltage sweep or a step voltage sweep. In a linear voltage sweep, the voltage is increased or decreased linearly over a specified range. In a step voltage sweep, the control voltage is swept in discrete steps. This may be useful for testing a speaker system at a specific voltage level to test a specific passive unit. Preferably, the linear voltage sweep has a linear voltage sweep slope. The slope of the linear voltage sweep can be selected to allow sufficient time between two consecutive passive units while still allowing testing of multiple consecutive passive units. If the linear voltage sweep of the control voltage over time is too steep, the speakers of consecutive passive units will be activated relatively quickly, leaving insufficient time to detect which speaker of which passive unit can be activated. For example, if the speaker system is placed in an echo-prone environment, this can make audio feedback difficult because two different speakers may be detected as active when only the first speaker is active. In other words, residual sound from the first speaker of the first passive unit may be detected as sound being received from the activation of a subsequent speaker of a subsequent passive unit being tested.

Claims

1. A speaker system comprising a main unit and a plurality of passive units, configured to test the plurality of passive units individually, The main unit and the plurality of passive units are connected to form a daisy-chain by at least control voltage signal connections, reference voltage signal connections, and audio signal connections. The aforementioned main unit is Control voltage to the plurality of passive units via the control voltage signal connection, The reference voltage to the plurality of passive units via the reference voltage signal connection, and Audio signals to the plurality of passive units via the aforementioned audio signal connection It is configured to generate, The speaker system further comprises a voltage adjustment unit positioned between each of the plurality of passive units on the reference voltage signal connection. Each voltage regulation unit is adapted to provide a local reference voltage to each passive unit, and the local reference voltage to the multiple passive units gradually increases or decreases among the passive units following the daisy chain. Each of the aforementioned passive units is Speaker unit and A comparator unit configured to compare the control voltage with a first voltage threshold and a second voltage threshold generated from the local reference voltage, and to generate an audio enable signal that enables the speaker unit to reproduce the audio signal when the control voltage is between the first voltage threshold and the second voltage threshold; Equipped with, The aforementioned main unit is a speaker system that receives feedback from each of the passive units.

2. The speaker system according to claim 1, wherein the voltage adjustment unit comprises at least one resistor.

3. The speaker system according to claim 1, wherein each passive unit is configured to generate the first voltage threshold and / or the second voltage threshold by voltage division using a voltage divider.

4. The speaker system according to claim 1, wherein the comparator unit comprises at least two comparators, the first comparator configured to compare a first voltage threshold with the control voltage, the second comparator configured to compare a second voltage threshold with the control voltage, the first comparator generating a first comparator digital output, the second comparator generating a second comparator digital output, and the first comparator digital output and the second comparator digital output being inputs to a logic gate, the logic gate being configured to output the audio enable signal in response to the input.

5. The speaker system according to claim 1, further comprising a supply signal connection and / or a ground signal connection.

6. The speaker system according to claim 1, wherein the main unit and the plurality of passive units are connected by at least five conductors configured to provide at least a supply signal connection, a ground signal connection, the reference voltage signal connection, the audio signal connection, and the control voltage signal connection.

7. The speaker system according to claim 1, wherein the main unit and the plurality of passive units are connected by eight conductors, the eight conductors being included in an Ethernet cable.

8. A method for testing a speaker system comprising a main unit and a plurality of passive units, wherein the main unit and the plurality of passive units are connected to form a daisy-chain by at least a control voltage signal connection, a reference voltage signal connection, and an audio signal connection, and the method is By generating a reference voltage that gradually increases or decreases between passive units along the daisy chain on the aforementioned reference voltage signal connection, a local reference voltage is provided to each passive unit. Providing a control voltage on the aforementioned control voltage signal connection, To generate audio signals to the plurality of passive units via the aforementioned audio signal connection, In each passive unit, the control voltage is compared with a first voltage threshold and a second voltage threshold generated from the local reference voltage, and an audio enable signal is generated that enables the speaker unit of the passive unit to reproduce the audio signal when the control voltage is between the first voltage threshold and the second voltage threshold. The main unit tests each passive unit by receiving feedback from each passive unit. A method that includes this.

9. The method according to claim 8, wherein the feedback is received by the main unit.

10. The method according to claim 9, wherein the feedback is a feedback current.

11. The method according to claim 8, wherein the feedback current is a spike current caused by the operation of the speaker unit.

12. The method according to claim 8, wherein at least one of the main unit and / or the plurality of passive units comprises at least one microphone.

13. The method according to claim 12, wherein the feedback is audio feedback, and the audio feedback is the audio signal reproduced by the passive unit and recorded by the at least one microphone.

14. The method according to claim 8, further comprising sweeping the control voltage on the control voltage signal connection from a first voltage level to a second voltage level.

15. A method for testing the speaker system according to claim 8, wherein the speaker system is the speaker system according to claim 1.

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