JP2001189993A - Speaker system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a speaker system, that can used stably under optimum conditions, even on the occurrence of faults in the driver unit of a trumpet-type speaker used for wide-band loudspeaking due to the harsh conditions for the unit. SOLUTION: The speaker system, where a plurality of voice coils are mounted on a voice coil bobbin of a dynamic driver unit having a single diaphragm, is characterized in its having a means that selects other voice coils, on the occurrence of a fault in a 1st voice coil, while the 1st voice coil is usually used to drive the diaphragm and the other voice coil is at a standby.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a loudspeaker system of a so-called trumpet type loudspeaker used for wide-range loudspeaking, and more particularly to a loudspeaker system having a plurality of independent voice coils for driving a diaphragm.

[0002]

2. Description of the Related Art Hitherto, a speaker system using a trumpet type speaker of this type has been widely spread and used in stadiums, schools, regional emergency broadcasts, on-vehicle broadcasts for elections, and the like. The loudspeaker system achieves clear high sound pressure with a powerful driver unit and an efficient trumpet horn.

[0003]

However, in the above-mentioned conventional speaker system, excessive input occurs in the speaker due to the operation of the user who wants to widen the loudspeaking range, and the voice coil is damaged or the voice coil is damaged due to the excessive input. There has been a problem that an accident such as separation of the voice coil from the diaphragm due to temperature rise occurs.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and has an object to optimize a trumpet-type speaker used for wide-range loudspeaker even when an abnormality occurs due to severe conditions. An object of the present invention is to provide a speaker system that can be used stably under various conditions.

[0005]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventor has found that the object can be achieved by providing a voice coil for occurrence of an abnormality in addition to the conventional voice coil. And completed the present invention.

That is, the present invention relates to a speaker system in which a plurality of voice coils are mounted on a voice coil bobbin of an electrodynamic driver unit having a single diaphragm. Drive the diaphragm with the other voice coil in standby state,
A speaker system having means for switching to another voice coil when an abnormality occurs in the first voice coil.

In a preferred embodiment of the speaker system of the present invention, the diaphragm is driven by the first voice coil, and when the first voice coil is disconnected during operation, the disconnection is detected by the detection system of the drive-side device. There is means for switching to another voice coil.

In a preferred embodiment of the speaker system of the present invention, the output of the amplifying device is connected to a plurality of voice coils.

In a preferred embodiment of the loudspeaker system of the present invention, there is provided a means for connecting the output of the amplifying device to a plurality of voice coils in series, and switching to another voice coil when one voice coil is disconnected.

In a preferred embodiment of the speaker system according to the present invention, an amplifier is independently connected to each of the plurality of voice coils.

In a preferred embodiment of the speaker system of the present invention, the first voice coil among the plurality of voice coils is connected to the amplifying device, and the other voice coils are used as temperature detecting means of the first voice coil. The amplifier device can perform feedback control corresponding to the temperature rise of the voice coil, and further has display means for displaying a temperature detection result as a temperature display or a danger display.

In a preferred embodiment of the speaker system of the present invention, the first voice coil among the plurality of voice coils is connected to the amplifying device, and the other voice coils are used as temperature detecting means of the first voice coil. When the temperature of the first voice coil rises, another voice coil operates as a driving voice coil.

In a preferred embodiment of the loudspeaker system of the present invention, a resistor is provided between the speaker amplifying device and the loudspeaker, the power input to the loudspeaker from the resistor is measured in units of time, and the loudspeaker is calculated from the product of the power and time. Means for detecting the temperature rise of the speaker and estimating the load state of the speaker.

In a preferred embodiment of the speaker system of the present invention, the output of the amplifying device is connected to a plurality of voice coils,
Means for periodically switching these voice coils are provided.

In a preferred embodiment of the speaker system of the present invention, a plurality of voice coils are provided in parallel or in series on a voice coil bobbin to have a plurality of impedances.

In a preferred embodiment of the speaker system of the present invention, a temperature sensor is provided on an equalizer in front of a diaphragm in the speaker, and the temperature sensor detects the temperature of the speaker in real time.

In the speaker system of the present invention, since a plurality of voice coils are provided in the speaker driver as described above, a loudspeaker may erroneously input excessive power of the speaker or operate the voice coil for a long time. However, accidents can be minimized even if heating occurs.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The speaker system of the present invention will be described below in detail with reference to the drawings, but the present invention is not limited to these.

FIG. 1A shows an example of a typical structure used as a driver unit of a trumpet speaker. A magnet 102, a center pole 106 and a top plate 105 are incorporated in a yoke 101, and a voice is mounted on a diaphragm 110. A structure in which a coil 104 is installed, the voice coil 104 is installed in a magnetic circuit, a dustproof net 108 is installed in a driver throat 116 having an equalizer 109 and a throat 107, and the yoke 101 and the driver throat 116 are fixed with screws 120. It is integrated. The structure of the diaphragm 110 is shown in more detail in the perspective view 114 of the diaphragm in FIG. 1B. The diaphragm 110 has a voice coil 112 mounted on a voice coil bobbin 119 and leads 113 and 115 of the voice coil 112 mounted on the voice coil bobbin 119. And
It is composed of a vibrating part 111 having a round front surface and a fixed part 117.

The sound output from the amplifying device is transmitted to the voice coil 1
04, the magnetic field of the strong magnet 102 and the magnetic field generated by the voice coil 104 cause interference with the diaphragm 11.
0 vibrates back and forth, is acoustically corrected by the equalizer 109, is output as acoustic vibration to the trumpet horn via the throat 107, and amplifies the acoustic input input to the amplifier.

If the input from the loudspeaker is excessive, FIG.
(B) The voice coil 112 provided on the voice coil bobbin 119 shown in (b) may be cut, or the adhesive for fixing the voice coil 112 to the voice coil bobbin 119 may be released, so that sound may not be output during use.

As shown in FIG. 2, the voice coil of the conventional speaker system has a single winding structure of a diaphragm 201 and a voice coil 202, and the voice coil 202 is adapted to the voice coil bobbin 203 of the diaphragm 201 to match the output impedance of the speaker. By specifying the impedance from 2-16Ω which is usually used as the impedance and winding it,
Align with the loudspeaker and vibrate at the output from the loudspeaker.

[0023] However, for the purpose of loudspeaking, when the background noise in the use environment increases from the time of normal use, power that is not normally considered beyond the specification may be continuously input to the speaker. That is, an excessive load is applied to the voice coil of the speaker, and disconnection or other accidents may occur.

On the other hand, the loudspeaker system of the present invention solves such a problem, as shown in FIG.
In addition to the first voice coil 302 provided on the voice coil bobbin 304, a diaphragm 301 provided with a second voice coil 303 is further configured to complete a speaker driver. The first voice coil and the second voice coil may be wound in a known manner depending on the purpose of the loudspeaker application or the purpose of use. For example, the first voice coil 302 and the second voice coil 303 may be overlapped and wound. Or a method in which a plurality of voice coils are wound side-by-side in parallel.

By using the apparatus as described above, when the first voice coil 302 is used for loudspeaking, when the voice coil is cut off or stops operating due to excessive input in the above-mentioned situation, etc. The connection to the two voice coils 303 can be changed to continue the loudspeaker operation.

Further, the first voice coil 302 and the second voice coil 303 may be used in parallel or in series, or the second voice coil 303 may be used for detection to prevent an accident from occurring in advance. Depending on the application, it is possible to construct a speaker system that can continuously use the function as a speaker even in an over-input state.

In the speaker system of the present invention, the diaphragm is driven by the first voice coil, and when the first voice coil is disconnected during operation, the disconnection is detected by the detection system of the driving device, and the second A means for switching to another voice coil such as a voice coil can be provided. For example, when driving a loudspeaker by installing a plurality of voice coils on a diaphragm, as shown in FIG.
, A voice coil abnormality detection 403 is provided at the output of the amplifier circuit 402, and the first voice coil 40 is provided at the output.
7 and a switch 406 for selecting either use of the second voice coil 408, and the first voice coil 4
07 and the second voice coil 408 are connected. The output of the abnormality detection 403 is connected to the switch control 404 to control the switching 406.

Since the abnormality detection 403 is provided on the output side of the amplifier circuit, when the speaker is disconnected and the load on the speaker becomes open, the output terminal of the amplifier circuit 402 has a lower load than in a normal load state. An abnormality in which the output is opened and the output current stops flowing can be recognized by the abnormality detection 403. Conversely, the first voice coil 407
Is short-circuited, the output current of the amplifier circuit 402 rises extremely, so the abnormality detection 403 recognizes that an abnormal state has occurred in the first voice coil 407.

When the disconnection of the first voice coil 407 is constantly monitored by the abnormality detection 403 in which the current is detected,
When excessive input is continuously input to the first voice coil 407 and the voice coil is cut off, the current for driving the voice coil of the amplifier circuit 402 does not flow through the first voice coil 407, so that the abnormality detection 403 is performed by the first voice coil 407. Upon determining that 407 has been disconnected, the abnormality detection 403 outputs a switching signal to the switch control 404, outputs a signal for switching to the second voice coil 408 to the switch 406, and outputs the signal to the first voice coil 4.
In the operation of switching from 07 to the second voice coil 408,
It enables continuous operation as a speaker.

When the first voice coil 407 is short-circuited, an excessive current flows to the abnormality detection 403 as compared with the normal state, so that the short-circuit abnormality of the first voice coil 407 can be detected.

As described above, the abnormality detection 403 which detects the disconnection or short-circuit abnormality of the voice coil inputs the detection data to the switch control 404 and switches the switching operation from the first voice coil 407 to the second voice coil 408. To be performed. Similarly, when the second voice coil 408 is initially driven and an abnormality such as disconnection or short circuit of the second voice coil occurs, an operation of switching from the second voice coil 408 to the first voice coil 407 is performed. When three or more voice coils are provided, the voice coil can be switched one after another by the same method, so that the speaker can be operated continuously.

If a plurality of voice coils are provided on the diaphragm 409 as described above, even if a failure occurs due to excessive input or severe continuous use, the voice coils are switched one after another according to the detection result of the abnormality detection 403. Since the speaker system can be used, the durability of the speaker system can be improved.

In the speaker system of the present invention, as shown in FIG. 5, the output of the amplifying device is connected to a plurality of voice coils (two in the figure).
Can be connected to FIG. 5A shows an example in which the input 501 is connected to the amplifier circuit 502, the output is connected in series to the first voice coil 503 and the second voice coil 504, and the diaphragm 505 is vibrated to increase the volume. FIG. 5 (b)
Is an example in which the input 506 is connected to the amplifier circuit 507, the output is connected in parallel to the first voice coil 508 and the second voice coil 509, and the diaphragm 510 is vibrated to increase the volume.

In this case, if each of the first voice coil 503 and the second voice coil 504 mounted on the diaphragm 505 is 8Ω, it must be connected in series to the 16Ω amplifier circuit 502 as shown in FIG. Can be. Diaphragm 510
If each of the first voice coil 508 and the second voice coil 509 provided in the above is 8Ω, it is possible to cope with a 4Ω amplifier by connecting in parallel as shown in FIG. 5B.

As described above, the impedance of the speaker and the amplifier can be adjusted by the plurality of voice coil impedances, and the external connection terminal of the voice coil is provided by using the first voice coil and the second voice coil as independent voice coils. This makes it possible to provide a speaker system that can flexibly cope with construction on site where a speaker is installed.

The loudspeaker system of the present invention can include means for connecting the output of the amplifying device to a plurality of voice coils in series and switching to another voice coil when one voice coil is disconnected. For example, as shown in FIG. 6, a voice input 601 is input to an amplifier circuit 602, and the output is connected in series to a first voice coil 607 and a second voice coil 606. The detection 603 is connected to the output of the amplification circuit 602, the output of the detection 603 is connected to the switching control 604,
The output is connected to a switching circuit 605, and the switching circuit 60
5 switches the speakers.

When the first voice coil 607 and the second voice coil 606 mounted on the diaphragm 608 are connected in series from the amplifier and the first or second voice coil is cut off, the amplifier circuit is opened. , Amplifying circuit 60
2, the output voltage increases. When the switch position of the switching circuit 605 is set to neutral and the voltage is detected, the first voice coil 607 or the second voice coil 60
6, when the output voltage of the amplifier circuit is reduced to approximately one half or greatly reduced, the switch position of the switching circuit 605 is connected to the normally operating voice coil, and the switching circuit 605 is connected. If the voltage of the amplifying circuit 602 does not drop when entering into any position, it is detected that the voice coil has been disconnected, and
A voice coil that operates normally by switching to another position is connected as a load of the amplifier circuit 602.

In the speaker system of the present invention, an amplifier can be connected to each of the plurality of voice coils independently. For example, as shown in FIG. 7, a voice input 701 is connected to a preamplifier 702, the output is connected to an amplifier circuit 703 and an amplifier circuit 704, and a first voice coil 705 and a second voice coil 706 are respectively connected to the outputs. When connected and driven, the diaphragm 707 is vibrated to increase the volume. In this case, the audio signal input 701 is output from the preamplifier 702 at the same phase and the same level, and the first voice coil 705 and the second voice coil 7 are output from the amplifier circuits 703 and 704, respectively.
06 is output.

With the above configuration, the diaphragm 707 can be driven by different voice coils,
If the output is the same, the driving force of the diaphragm will be at the same level as applying twice the input to one voice coil, and even if the first or second voice coil is disconnected due to excessive input, the speaker will Although the sound pressure level of the voice coil is lowered, the loudspeaker operation can be continued because any one of the voice coils is operating.

According to the speaker system of the present invention, the first voice coil of the plurality of voice coils is connected to the amplifying device, and the other voice coils are used as temperature detecting means of the first voice coil. Feedback control corresponding to the temperature rise can be performed on the amplifier. For example, as shown in FIG. 8A, the connection to the first voice coil 805 is performed as usual, that is, the voice input 801 is amplified by the preamplifier 802 and the amplifier circuit 803, and supplied to the first voice coil 805. 807 is vibrated to increase the volume. But,
When the first voice coil 805 is continuously operated in an over-input state, the second voice coil 806, which is wrapped or placed in close proximity, is also heated by the first voice coil 805, and the temperature rises. In this case, the second voice coil 806 is connected to the temperature detection 804 for temperature detection, and the temperature detection result is connected to the preamplifier 802 for control. The temperature detection 804 is connected to a temperature display 810 for displaying the temperature rise of the first voice coil 805.

In the temperature detection 804, the second voice coil 8
The temperature of the second voice coil 806 can be known from the change in the current value by flowing a current through the resistor 06. Since the voice coil is generally made of copper as a base material, the temperature characteristic substantially approximates the temperature characteristic of copper. As shown in the temperature characteristic 808 of FIG. 8B, the resistance of the voice coil increases in proportion to the temperature rise. Therefore, the temperature can be detected from the voice coil resistance change 809. Since the second voice coil 806 is installed close to the first voice coil 805, it has a similar temperature. As described above, the second voice coil 8
06, the first voice coil 8
05 temperature rise can be detected.

A change in the resistance of the second voice coil 806 is detected by a change in current. If the voice coil becomes high temperature and excessive input continues, it is dangerous if the temperature is too high. The input to the first voice coil 805 is reduced by lowering the gain of the input 801 to suppress excessive input to the first voice coil 805. When a dangerous temperature rise is suppressed by an excessive input to the first voice coil 805, the restriction on the preamplifier 802 is released. By controlling the excessive input to the first voice coil 805 as described above, a stable operation for a long time can be realized.

As described above, the speaker system of the present invention regards the change in the resistance value of the voice coil caused by the temperature rise due to the excessive input of the voice coil of the second voice coil 806 as the temperature change. Detects that there is a risk of disconnection of the voice coil itself or deterioration of the adhesive, the temperature detection 804 performs a temperature display or a danger display on the temperature display 810. The display can also indicate, for example, the cause of the decrease in volume. In addition, since the temperature and the state are displayed by the temperature display 810, the operator can adjust the volume by looking at the display and adjust the volume so that an excessive input to the driver unit can be prevented.

The speaker system of the present invention comprises a plurality of voice coils (first voice coil 906, second voice coil 90) mounted on a diaphragm 908 of the speaker as shown in FIG.
In 7), each of the speaker lines connecting the output circuit 905 is provided with a detection resistor r 909 and a detection resistor r 910 that are negligible with respect to the impedance of the speaker. The power per fixed time flowing into the coil 906 and the second voice coil 907 is fed back to the detection 903 and the detection 904 as information of over-input, and the preamplifier 902 is controlled to reduce the amplification of the voice of the input 901. First voice coil 9
06 and the input to the second voice coil 907 can be reduced to a safe level as power consumption. In this method, the excessive input flowing into the voice coil is not responded to at an instantaneous peak, but the degree of danger is detected based on power consumption per fixed time, and the input to the speaker is controlled.

In the speaker system of the present invention, the output of the amplifying device is connected to a plurality of voice coils, and the voice coils can be switched periodically to reduce the stress of the voice coils.

For example, as shown in FIG. 10, an amplifier circuit 1002 for driving a speaker is connected to a first voice coil 1007 and a second voice coil 1008 via a switch 1006, and the switch 1006 is a signal from a timer 1004 for a predetermined time. The switch of the switch 1006 is switched to the first voice coil 1007 and the second voice coil 1008 every time. Also, if the voice input 1001 is higher than the rating and the input clearly indicates that the voice coil is overloaded, the voice input is notified to the overload detection 1003.
The switching speed of the timer 1004 is set higher than before so that the load on the voice coil at regular intervals is reduced.

In the above manner, a specific voice coil can cope with a long-time over-input state without stress and can respond while resting, so that the speaker system can withstand a long-time over-input. Can be constructed.

The speaker system of the present invention can implement a speaker capable of coping with various input impedances by mounting a plurality of voice coils in parallel or in series on a voice coil bobbin. For example, as shown in FIG. 11, a plurality of voice coils, that is, a first voice coil 1105, a second voice coil 1106, a third voice coil 1107, and a fourth voice coil 1108 are provided on a diaphragm 1109, and the impedance of the voice coil is reduced. Z1 1001, Z2 1
102, Z3 1103, Z4 1104 as diaphragm 11
09.

At this time, when the impedance of each voice coil is Z1, Z2, Z3, Z4, and each impedance is 2Ω, Z1 + Z2 + Z3 + Z4 = 8Ω Z1 // Z2 + Z3 // Z4 = 2Ω (// means parallel. Z1 + Z2 = 4Ω As described above, a speaker that can cope with various impedances can be realized by the connection method. If necessary, a configuration may be employed in which one of the plurality of voice coils is used for temperature detection.

In the speaker system of the present invention, a temperature sensor is provided on an equalizer in front of the diaphragm in the speaker, and the temperature of the speaker can be detected in real time by the temperature sensor. For example, as shown in FIG. 12, voice is input to an input 1201 and a preamplifier 1202, connected to an output 1203 and an output 1204, and each output is connected to a first voice coil 1205 and a second voice coil 1206. Equalizer 12 that vibrates diaphragm 1207 with sound, and performs acoustic correction of diaphragm 1207
08, a temperature sensor 1209 is provided, and the output of the temperature sensor 1209 is converted into an electric signal by the temperature detection 1210 and input to the preamplifier 1202, and the input of the speaker is controlled by the temperature rise of the speaker. Further, the sensor position is not limited to the equalizer, and may be installed at any appropriate position where the temperature of the voice coil can be sensed.

In the speaker system described above, an accident such as disconnection may occur due to a rise in temperature of the voice coil due to a long-term over-input operation or a voice input exceeding a rating in a short time from the above-mentioned voice application. Therefore, by measuring the temperature of the temperature sensor 1209 provided on the front surface of the diaphragm, the voice coil temperature is predicted from the temperature in the speaker driver, and the temperature detection 1210 corrects the voice coil temperature with a prediction coefficient to obtain a dangerous voice coil temperature. If it is predicted that a temperature rise has occurred in the voice coil, the level of the amplification of the preamplifier 1202 is forcibly reduced to lower the temperature of the voice coil, thereby avoiding the danger of disconnection or the like in advance, and Temperature detection 1 when the voice coil is in a safe temperature state by operating
Judging from the result of 210, the gain of the preamplifier 1202 is returned to the conventional state, and the loudspeaking operation is performed.

[0052]

As described above, an excessive input is applied from a use environment to a driver unit of a trumpet loudspeaker for wide-range loudspeaking, resulting in severe use conditions.
According to the speaker system of the present invention, since a plurality of voice coils for driving the diaphragm are prepared and controlled by various methods, the life of the driver unit can be extended, and a more stable loudspeaker system can be supplied. .

[Brief description of the drawings]

FIG. 1A is an explanatory view of a basic speaker driver structure. FIG. 1B is a perspective view of a diaphragm.

FIG. 2 is an explanatory diagram of an example of installation of a conventional voice coil.

FIG. 3 is an explanatory diagram of an example of a voice coil device according to the present invention.

FIG. 4 is an explanatory view of a device example of the speaker system of the present invention.

FIG. 5 (a) is an explanatory view of an example of a speaker system of the present invention (a voice coil is connected in series to an amplifier circuit). FIG. 5 (b) is an example of an apparatus of a speaker system of the present invention (a voice coil is connected in parallel to an amplifier circuit). Illustration

FIG. 6 is an explanatory view of a device example of the speaker system of the present invention.

FIG. 7 is an explanatory diagram of an apparatus example of the speaker system of the present invention.

FIG. 8A is a diagram illustrating an example of a speaker system according to the present invention. FIG. 8B is a graph showing the temperature characteristics of the resistance of the voice coil.

FIG. 9 is an explanatory view of a device example of the speaker system of the present invention.

FIG. 10 is an explanatory diagram of an apparatus example of the speaker system of the present invention.

FIG. 11 is an explanatory view of a device example of the speaker system of the present invention.

FIG. 12 is an explanatory diagram of an apparatus example of a speaker system according to the present invention.

[Explanation of symbols]

 101. Yoke 102. Magnet 104. Voice coil 105. Top plate 106. Center pole 107. Throat 108. Dustproof net 109. Equalizer 110. Diaphragm 111. Vibrating part 112. Voice coil 113. Lead wire 114. Diaphragm perspective view 115. Lead wire 116. Driver throat 117. Fixed part 118. Voice coil packing 119. Voice coil bobbin 120. Screw 201. Diaphragm 202. Voice coil 203. Voice coil bobbin 301. Diaphragm 302. First voice coil 303. Second voice coil 304. Voice coil bobbin 401. Input 402. Amplifying circuit 403. Abnormality detection 404. Switch control 406. Switching 407. First voice coil 408. Second voice coil 409. Diaphragm 501. Input 502. Amplifying circuit 503. First voice coil 504. Second voice coil 505. Diaphragm 506. Input 507. Amplifier circuit 508. First voice coil 509. Second voice coil 510. Diaphragm 601. Input 602. Amplifying circuit 603. Detection 604. Switching control 605. Switching circuit 606. Second voice coil 607. First voice coil 608. Diaphragm 701. Input 702. Preamplification 703. Amplifying circuit 704. Amplifying circuit 705. First voice coil 706. Second voice coil 707. Diaphragm 801. Input 802. Preamplification 803. Amplifying circuit 804. Temperature detection 805. First voice coil 806. Second voice coil 807. Diaphragm 808. Temperature characteristics 809. Voice coil resistance change 810. Temperature display 901. Input 902. Preamplification 903. Detection 904. Detection 905. Output circuit 906. First voice coil 907. Second voice coil 908. Diaphragm 909. Sensing resistor r 910. Sensing resistor r 1001. Input 1002. Amplifier circuit 1003. Overload detection 1004. Timer 1005. Switching control 1006. Switching 1007. First voice coil 1008. Second voice coil 1009. Diaphragm 1101. Z1 1102. Z2 1103. Z3 1104. Z4 1105. First voice coil 1106. Second voice coil 1107. Third voice coil 1108. Fourth voice coil 1109. Diaphragm 1201. Input 1202. Preamplification 1203. Output 1204. Output 1205. First voice coil 1206. Second voice coil 1207. Diaphragm 1208. Equalizer 1209. Temperature sensor 1210. Temperature detection

Claims (12)

[Claims] 1. A speaker system in which a plurality of voice coils are provided on a voice coil bobbin of an electrodynamic driver unit having a single diaphragm, wherein the first voice coil of the plurality of voice coils includes the diaphragm. And driving the other voice coil to a standby state, and switching to another voice coil when an abnormality occurs in the first voice coil. 2. A means for driving a diaphragm with a first voice coil and detecting a disconnection by a detection system of a drive side device when the first voice coil is disconnected during operation and switching to another voice coil. 2. The method according to claim 1, wherein
The speaker system as described in the above. 3. The speaker system according to claim 1, wherein the output of the amplifier is connected to a plurality of voice coils. 4. The output of the amplifying device is connected in series to a plurality of voice coils, and when one voice coil is disconnected,
2. The speaker system according to claim 1, further comprising means for switching to another voice coil. 5. The speaker system according to claim 1, wherein an amplifier is independently connected to each of the plurality of voice coils. 6. A feedback device that matches a temperature rise of a voice coil by connecting a first voice coil among a plurality of voice coils to an amplifier and using another voice coil as temperature detecting means of the first voice coil. The speaker system according to claim 1, wherein the control can be performed on the amplifying device. 7. The speaker system according to claim 6, further comprising display means for displaying a temperature detection result as a temperature display or a danger display. 8. The temperature of the first voice coil rises by connecting the first voice coil among the plurality of voice coils to the amplifying device and using the other voice coils as temperature detecting means of the first voice coil. 2. The speaker system according to claim 1, wherein the other voice coil operates as a driving voice coil. 9. A loudspeaker is provided between a speaker amplifying device and a loudspeaker, the power input to the loudspeaker is measured in units of time from the resistor, and a temperature rise of the loudspeaker is detected from a product of the power and the time. 2. The speaker system according to claim 1, further comprising means for estimating a load state of the speaker. 10. The loudspeaker system according to claim 1, further comprising means for connecting an output of the amplifying device to a plurality of voice coils and periodically switching these voice coils. 11. The speaker system according to claim 1, wherein a plurality of voice coils are provided in a voice coil bobbin in parallel or in series to have a plurality of impedances. 12. The speaker system according to claim 1, wherein a temperature sensor is provided on an equalizer in front of a diaphragm in the speaker, and the temperature of the speaker is detected in real time by the temperature sensor.