KR102172489B1 - Crossover Network, Multiway Speaker System and Audio System Using the Same, Frequency Dividing Method of Crossover Network - Google Patents

Abstract

The present invention relates to a crossover network, a multi-way speaker system and an audio system using the same, and a frequency dividing method of the crossover network, which eliminates a capacitor which adversely affects sound quality and employs only one transformer to realize accurate symmetric frequency division at a crossover point. According to the present invention, the crossover network includes a first transformer which receives an audio signal and divides the audio signal into two frequency bands of a low frequency audio signal and a medium frequency audio signal, and applies the low frequency audio signal to a low frequency speaker and the medium frequency audio signal to a medium and high frequency speaker. The first transformer includes: a primary coil having one end wound around a core and the other end connected to an input terminal of the low frequency speaker; and a secondary coil which is wound on the core, and has one end which is grounded and the other end which is connected to an input terminal of the medium and high frequency speaker.

Description

Crossover Network, Multiway Speaker System and Audio System Using the Same, Frequency Dividing Method of Crossover Network}

The present invention relates to a crossover network, and more particularly, a crossover network capable of implementing accurate symmetric frequency division at a crossover point by removing a capacitor that adversely affects sound quality and employing only one transformer, and a multiway using the same. The present invention relates to a speaker system, an audio system, and a frequency division method of a crossover network.

A speaker is an electro-acoustic converter that converts an audio signal in the audible frequency band of 20 to 20,000 Hz amplified by a power amp into a sound signal that can be heard by humans.

The principle of the speaker is that the voice coil moves by the change of the current applied to the voice coil in a certain magnetic field according to the Fleming's Left Hand Rule, and the vibration plate connected to the voice coil is interlocked to determine the density of the air around the diaphragm. It is a device that changes it like a change amount and converts it into acoustic energy that can be heard by humans.

However, due to the physical limitations of the speaker's size, diaphragm, materials applied to magnetic circuits, and design methods, there is no full-range speaker that reproduces the entire range of 20 to 20,000 Hz evenly with one speaker. It is divided into a 2-way) speaker system and a 3-way speaker system divided into low, mid, and high frequencies, or a multiway speaker system.

In a 2-way or higher multi-way speaker system, the input audio signal is amplified with a power amplifier and the power amplified audio signal is a passive crossover network consisting of LC, RC or RL, etc. That is, it is applied to the filter circuit and distributed for each frequency band, and then independently applied to a plurality of speakers for each high, medium, and low range.

The multiway speaker includes at least one high-range speaker (tweeter) for reproducing a high-frequency audio signal, at least one midrange speaker (midrange) for reproducing an intermediate frequency audio signal, and at least one for reproducing a low-frequency audio signal. It may be implemented in a form including a low-frequency speaker (or woofer).

Conventionally, a crossover network supporting a 2-way speaker system has used a filter circuit including at least one capacitor and one or more inductors, and also includes one or more resistors.

However, a passive crossover network that divides the frequency band by an LC filter circuit composed of an inductor and a capacitor is a passive element, a large-capacity electrolytic capacitor and an inductor (coil). ) (Or resistance), it is difficult to accurately match the crossover frequency and level, and unwanted crossover distortion and over-amplification may occur depending on the characteristics and temperature of the component.

In other words, in the vicinity of the crossover frequency band, the same frequency sound is emitted from the two speaker units, and when the crossover point where the mid-range audio signal and the low-range audio signal meet is not accurate or the slope of the slope is different, the corresponding frequency band There is a problem in that the amount of the low range is reduced and the quality of the sound is also degraded due to interference between the sounds of each other due to over-amplification in

In general, the higher the order of the crossover network, the more sensitive the filter device is. For example, a primary crossover network decreases at a rate of -6dB/octave, and a secondary crossover network decreases at a rate of -12dB/octave.

In Korean Patent Publication No. 10-1843424 (Patent Document 1), an input terminal is connected to an output terminal of a first power amplifier, an output terminal is connected to an input terminal of a mid-range speaker, and a mid-range audio signal from the audio signal input from the first power amplifier. A condenser for extracting and applying it to the mid-range speaker; And an input terminal connected to an input terminal and an output terminal of the capacitor, and an output terminal connected to an input terminal of a low-frequency speaker through a second power amplifier. By inducing a voltage corresponding to a current applied to the capacitor, the voltage corresponding to the voltage across the capacitor A multi-way speaker system including a transformer for applying a symmetrical signal of the mid-range audio signal and an output signal spectrum as a signal to the low-frequency speaker through the second power amplifier is proposed.

The multi-way speaker system presented in Patent Document 1 has succeeded in perfect separation at the crossover frequency, but the structure is complex and requires the use of a multi-amplifier system of a low-range power amplifier and a mid-range power amplifier, so more than two expensive power amplifiers are required. There is a necessary problem.

In addition, Patent Document 1 continuously employs a capacitor as a high pass filter (HPF), and thus, there is a problem of deteriorating the high fidelity of the reproduced sound. In other words, negative intermodulation in the high frequency range is generated by the capacitor.

Capacitors and inductors used in crossover networks are typically expensive because of their size, capacity and power requirements, so these additional components significantly increase the cost of the speaker system.

Moreover, Patent Document 1 discloses that the harmonic of the low- and high-band signals formed in the low- and high-range crossover frequencies, respectively, is inaccurate, so that intermodulation may occur in that portion, and the reproduced sound may become cloudy.

In addition, tolerances related to capacitors tend to require very expensive components when trying to accurately match or characterize components for a speaker system.

: Korean Patent Publication No. 10-1843424

Accordingly, the present invention is to solve the problems of the prior art, and its object is a crossover network capable of implementing accurate symmetric frequency division at a crossover point using only one transformer, and It is to provide a multiway speaker system and audio system.

Another object of the present invention is to provide a crossover network including means for removing a sound pressure difference between speakers for each sound range, and a multiway speaker system using the same.

Another object of the present invention is to eliminate high-frequency intermodulation by removing a capacitor that adversely affects sound quality in a multiway speaker network, and to implement a natural sound such as a full-range capacitor-free crossover network and the same. It is to provide a used multi-way speaker system.

Another object of the present invention is to divide the low and middle bands into a single transformer, and the middle and high band signals excluding the low pass signal passing through the primary side of the transformer are separated by an accurate crossover frequency, and a symmetric mid and high band with the same slope The goal is to provide a crossover network capable of implementing a perfect crossover by inducing a frequency to the secondary side and a multiway speaker system using the same.

Another object of the present invention is to provide a crossover network that can be simply implemented using a multiway speaker network having one transformer, and a frequency division method of a multiway speaker system and a crossover network using the same. .

For the above purposes, the crossover network according to an embodiment of the present invention receives an audio signal and separates it into two frequency bands of a low frequency audio signal and a medium frequency audio signal, and applies the low frequency audio signal to a low frequency speaker. And a first transformer applied to the medium and high frequency audio signal to a medium and high frequency speaker, wherein the first transformer includes a primary coil having one end wound around a core and the other end connected to the input terminal of the low frequency speaker; And a secondary coil having one end grounded after being wound around the core and the other end connected to the input end of the middle and high-pitched speaker.

A crossover network according to an embodiment of the present invention includes a plurality of output taps for attenuating the output of the secondary coil of the transformer to compensate for a difference in sound pressure between the low-pitched speaker and the mid-range speaker; A tap selector configured to connect one of a plurality of output taps to a mid-range speaker in response to a difference in sound pressure between the low-pitched speaker and the mid-range speaker; And an impedance matching resistor inserted between the output terminal of the secondary coil and the ground to match the impedance between the primary coil and the secondary coil of the first transformer.

The difference in sound pressure between the low-pitched speaker and the mid-range speaker may be one of -6db/oct, -8db/oct, -10db/oct, and -12db/oct.

The crossover frequency at which the frequency separation between the low frequency audio signal and the medium frequency audio signal is performed may be a cutoff frequency determined by an inductance value of a primary coil of the transformer and an impedance of a low frequency speaker.

In the crossover network according to another embodiment of the present invention, the audio signal power amplified by the power amplifier passes through the primary coil and the first frequency is divided based on the first crossover frequency, so that the low frequency audio signal is applied to the low-frequency speaker. And a first transformer for generating an audio signal of a separated medium and high frequency frequency by being guided to a secondary coil of the first transformer, the audio signal of the medium and high frequency frequency excluding the low frequency audio signal; And a second frequency division is performed based on a second crossover frequency while passing through the first coil after the audio signal of the mid-range frequency is applied to the primary coil, so that the intermediate frequency audio signal is applied to the mid-range speaker, and the intermediate frequency The high-frequency audio signal, excluding the audio signal, is guided to the secondary coil, and the audio signal of the high frequency frequency separated by the secondary coil is a second transformer applied to the high-frequency speaker.

The first transformer has one end connected to the output terminal of the power amplifier and wound on the core, and the other end is connected to the input terminal of the low-range speaker, and the primary coil is wound on the core, and one end is grounded and the other end is 1 of the second transformer. And a secondary coil connected to a secondary coil, wherein the second transformer has one end connected to the output end of the secondary coil of the first transformer, and the other end connected to the input end of the midrange speaker after being wound on the core And a secondary coil having one end grounded and the other end connected to the input end of the high-frequency speaker after being wound around the core.

The first crossover frequency fc may be obtained by Equation 1 below.

[Equation 1]

Here, R is the impedance of the low-range speaker and L is the inductance of the primary coil.

A crossover network according to another embodiment of the present invention includes a plurality of transformers in which an output of a secondary coil of a front-end transformer is connected to a primary coil of a next-stage transformer, wherein each of the plurality of transformers is 1 of the front-end transformer. The primary frequency of the low-frequency signal is separated from the input signal from the primary coil, and the frequency signal of the remaining band is induced to the secondary coil and separated, and then the frequency signal of the remaining band is applied to the primary coil of the rear transformer. The frequency can be divided into frequency bands of.

According to another embodiment of the present invention, a frequency division method of a crossover network includes applying an input signal to be frequency-divided to an input terminal of a primary coil of a transformer; Separating and outputting a low-frequency signal from an input signal through the primary coil and from an output terminal of the primary coil; And inducing and separating the high-frequency signals of the remaining bands excluding the low-frequency signals to the secondary coil of the transformer, wherein the low-frequency signal is separated by the inductance value of the primary coil of the transformer and the impedance of the low-frequency speaker. It characterized in that it is made at the determined cutoff frequency.

A multi-way speaker system according to another embodiment of the present invention includes a low-frequency speaker; Midrange speakers; Treble speakers; A first transformer for receiving the audio signal and separating it into two frequency bands of a low frequency audio signal and a medium frequency audio signal, applying the low frequency audio signal to the low frequency speaker, and outputting the medium frequency audio signal; And separating the middle frequency audio signal into two frequency bands of an intermediate frequency audio signal and a high frequency audio signal after receiving the middle frequency audio signal, and applying the intermediate frequency audio signal to the midrange speaker and the high frequency audio signal to the high frequency speaker. It characterized in that it includes; a second transformer.

A low-frequency audio signal is separated from the audio signal received from the output terminal of the primary coil while passing through the primary coil of the first transformer, and the first frequency is divided based on the first cutoff frequency, and the received audio signal The medium and high frequency audio signals, excluding the low frequency audio signal from, are guided to and separated from the secondary coil of the first transformer, and the separated medium and high frequency audio signal passes through the primary coil of the second transformer, while passing through the primary coil of the second transformer. The intermediate frequency audio signal is separated from the output terminal of the coil, and the second frequency is divided based on the second cutoff frequency, and the remaining high frequency audio signals excluding the intermediate frequency audio signal separated from the intermediate frequency audio signal are the second transformer. It can be separated by being induced into the secondary coil of.

An audio system according to the present invention includes a power amplifier for power amplifying an audio signal; Bass speaker; Midrange speakers; Treble speakers; A first transformer for receiving the power-amplified audio signal and separating it into two frequency bands of a low frequency audio signal and a medium frequency audio signal, applying the low frequency audio signal to the low frequency speaker and outputting the medium frequency audio signal; And separating the middle frequency audio signal into two frequency bands of an intermediate frequency audio signal and a high frequency audio signal after receiving the middle frequency audio signal, and applying the intermediate frequency audio signal to the midrange speaker and the high frequency audio signal to the high frequency speaker. It characterized in that it includes; a second transformer.

As described above, in the present invention, accurate symmetric frequency division can be implemented at a crossover point by using only one transformer.

In the present invention, as a means for removing the difference in sound pressure between speakers for each sound range, by adding a plurality of output taps to the secondary side of the transformer, the balance between the mid-range audio signal applied to the low- and mid-range speakers and the low-range audio signal is accurately balanced. The sound pressure difference can be simply and effectively eliminated.

In addition, in the present invention, the high pass filter of the multiway speaker network adversely affects sound quality, but by removing the necessary bad capacitor, intermodulation in the high frequency range can be eliminated and natural sound such as full range can be realized. .

In addition, in the present invention, the low and high frequencies are divided into one transformer, and the high and high frequency signals excluding the low frequency signals that have passed through the primary side of the transformer are separated by an accurate crossover frequency, and a symmetric mid and high frequency frequency with the same slope By inducing it to the secondary side, a perfect crossover can be realized.

In the present invention, by using only one transformer equipped with a plurality of output taps, the difference in sound pressure between speakers for each sound range is the simplest cross, such as -6db/oct, -8db/oct, -10db/oct, -12db/oct, etc. Over network can be implemented.

1 is a circuit diagram showing a multiway speaker system including a crossover network divided into two frequency bands according to a first embodiment of the present invention.
2 is an explanatory diagram showing that symmetric frequency division is performed at a crossover point while passing through a crossover network according to the present invention.
3 is a circuit diagram showing a multiway speaker system including a crossover network including means for removing a sound pressure difference between speakers for each sound region according to a second embodiment of the present invention.
4 is a circuit diagram showing a multiway speaker system including a crossover network divided into three frequency bands according to a third embodiment of the present invention.
5A and 5B are diagrams illustrating frequency division in two stages in a crossover network according to a third embodiment of the present invention, respectively.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings and preferred embodiments. For reference, in the following description, detailed descriptions of known functions and configurations that may unnecessarily obscure the subject matter of the present invention are omitted.

FIG. 1 is a multiway speaker system including a crossover network divided into two frequency bands according to a first embodiment of the present invention, and will be described in detail with reference to FIG. 1.

Referring to FIG. 1, a multi-way speaker system according to a first embodiment of the present invention largely includes a power amplifier 10, a crossover network 20, a low-frequency speaker 30, and a mid-range speaker 40.

In the multiway speaker system according to the first embodiment of the present invention, after power amplification of the input audio signal by the power amplifier 10, the power amplified audio signal is converted to a low frequency audio signal and a medium frequency audio signal through a crossover network 20. The signal is divided into two frequency bands, the low-frequency audio signal is applied to the low-frequency speaker 30, and the medium-frequency audio signal is applied to the high-frequency speaker 40.

In general, a low-frequency speaker 30 for reproducing a low-frequency audio signal applies a woofer, and a high-frequency speaker 40 for reproducing a high-frequency audio signal employs a tweeter.

The crossover network 20 according to the first embodiment of the present invention may be implemented using only one transformer T1.

The transformer T1 has one end connected to the output terminal of the power amplifier 10 and wound on the core, and the other end connected to the input terminal of the low-frequency speaker 30, and the primary coil L1 and the primary coil L1. ) And a predetermined turn ratio n, one end is grounded, and the other end, that is, the output end OT, includes a secondary coil L2 connected to the input end of the high-frequency speaker 40.

When the impedance and sound pressure of the low-frequency speaker 30 and the mid-range speaker 40 are the same, the inductance values of the primary coil L1 and the secondary coil L2 may be set to be the same. In this case, the turns ratio (n) is 1.

The crossover network 20 of the present invention drives the low frequency speaker 30 by extracting a low frequency audio signal from the power amplified audio signal applied to one end of the primary coil L1 of the transformer T1.

Inductors are used as low-pass filters (LPF) because they pass low-frequency signals well and block high-frequency signals. The present invention focuses on this point, and proposes a crossover network 20 capable of separating and extracting low-frequency audio signals and high-frequency audio signals from the primary coil L1 and the secondary coil L2 of the transformer T1, respectively. do.

In the crossover network 20 of the present invention, the audio signal (middle and high frequency) excluding the low-frequency audio signal that has passed through the low-frequency speaker 30 at the primary side of the transformer T1 is the secondary side secondary coil L2 of the transformer T1. ) Is guided and transmitted to the middle and high range speaker 40 to perform frequency division.

In addition, the low-frequency audio signal passing through the primary coil L1 of the transformer T1 by the time constant τ of the low-pass filter (LPF) appears in the low-frequency speaker 30, and the remaining frequency band (i.e. The audio signal of) is guided to the secondary side of the transformer T1, that is, the secondary coil L2, and appears on the high-frequency speaker 40 connected to the output terminal of the secondary coil L2.

At this time, the most ideal energy transfer (symmetric frequency division) state is when impedance matching between the primary side and the secondary side of the transformer T1 is achieved.

For example, when the impedance R1 of the low-range speaker 30 is 8Ω, the impedance R2 of the middle-high-range speaker 40 on the secondary side of the transformer T1 in the first embodiment shown in FIG. 1 is 8Ω. And, when the efficiency of the low-pitched speaker 30 and the mid-range speaker 40 is the same (that is, when there is no difference in sound pressure between the low-frequency speaker 30 and the mid-range speaker 40), the most ideal transmission is achieved.

As a result, the power-amplified audio signal passes through the primary coil L1 of the transformer T1 and passes only the audio signal in the low-frequency band lower than the cutoff frequency fc (that is, the crossover frequency), so that the low-frequency speaker 30 The audio signal of the remaining band, that is, the high frequency band, which is applied to and does not pass through the primary coil L1 of the transformer T1 may be extracted from the secondary coil L2 of the transformer T1.

The time constant (τ) of the low-pass filter (LPF) is determined by the inductance value of the primary-side primary coil (L1) of the transformer (T1).

The cutoff frequency fc at this time is calculated as shown in Equation 1 below based on the calculation formula of the low pass filter LPF formed by the primary coil L1 of the transformer T1 and the low frequency speaker 30.

Here, R is the impedance of the low-range speaker 30, and L is the inductance of the primary coil L1.

In the crossover network 20 according to the present invention, the cutoff frequency determined by Equation 1 is determined by the inductance of the primary coil L1 of the transformer T1 and the impedance of the low-range speaker 30 as shown in FIG. 2. Based on (fc) (i.e., the crossover frequency), the low-frequency (low-frequency) audio signal extracted from the primary coil (L1) of the transformer (T1) and the intermediate frequency and high-frequency automatically extracted from the secondary coil (L2) ( The mid-range) audio signal represents a symmetrical spectrum, that is, symmetric frequency division can be realized based on a crossover point.

As described above, the crossover network 20 according to the first embodiment of the present invention is implemented using only one transformer (T1), and can directly drive the speakers of each band without using a separate power amplifier. I can.

The crossover network 20 according to the first embodiment of the present invention illustrates a case where the impedance and sound pressure of the low-frequency speaker 30 and the mid-range speaker 40 are the same, and in the present invention, the low-frequency speaker 30 and the used sound pressure are the same. Even when there is a difference in sound pressure between the sound range speakers 40, it can be applied as in the second embodiment.

In the case where the efficiency of the low-range speaker 30 is 100dB/W and 8Ω, and the efficiency of the mid-range speaker 40 is 110dB/W and 16Ω, the difference in efficiency and impedance between each speaker unit occurs, so appropriate energy transfer and distribution are required. For this purpose, it is preferable to provide a separate appropriate output tap (TAP) and an impedance correction resistor (R3) on the secondary side of the transformer (T1).

3 is a circuit diagram showing a multiway speaker system including a crossover network including a sound pressure difference compensating means for compensating for a sound pressure difference between speakers for each sound range according to a second embodiment of the present invention.

Referring to FIG. 3, in the multiway speaker system according to the second embodiment of the present invention, a plurality of output taps (T11) in order to balance the sound pressure difference between a low-range speaker and a high-range speaker in the crossover network 21 are eliminated. It differs from the first embodiment in that -T15) is drawn out from the secondary coil L2 of the transformer T1.

Accordingly, when describing the second embodiment, the same parts as those of the first embodiment are given the same reference numerals, and detailed descriptions are omitted.

The crossover network 21 according to the second embodiment of the present invention has a plurality of outputs corresponding to the difference in sound pressure between the low-range speaker 30 and the mid-range speaker 40 in the secondary coil L2 of the transformer T1. Taps T11-T15 are added, and a tap selector SW for selecting one of the plurality of output taps T11-T15 is provided between the plurality of output taps T11-T15 and the mid-range speaker 40. connected.

The sound pressure difference, efficiency, and impedance matching resistance values for each output tap (T11-T15) are summarized in Table 1 below.

Sound pressure difference Output tab (efficiency) Resistance for impedance correction (R3) 0 T11 (100%) -6dB/oct T12 (50%) R1×1.15 -8dB/oct T13 (40%) R1×1.09 -10dB/oct T14 (31.5%) R1×1.05 -12dB/oct T15 (25%) R1×1.04

When a sound pressure difference occurs between the low-pitched speaker 30 and the mid-range speaker 40, the sound pressure of the middle-high-pitched speaker 40 is generally high, so that the sound of the mid-range speaker 40 (ie, tweeter) is attenuated. It is required to give.

As shown in Table 1 above, when the difference in sound pressure between the low-pitched speaker 30 and the mid-range speaker 40 is, for example, -10 dB, the secondary coil L2 of the transformer T1 (that is, the secondary winding) When the output tap (T14) having an efficiency of 31.5% is connected to the mid-range speaker 40, the difference in sound pressure can be eliminated (that is, 20log0.315 = -10dB).

However, when the tap selector (SW) is rotated and the output tap (T14) with an efficiency of 31.5% is connected to the 16Ω mid-range speaker 40, the impedance (R2) of the secondary coil (L2) of the transformer (T1) is approximately 160Ω. Since it becomes (3.17×3.17×16=160.8Ω), the energy cannot be transferred properly because the impedance does not match.

At this time, an impedance matching resistor (R3) is connected between the output terminal (T11) of the secondary coil (L2) of the transformer (T1) and the ground to transfer energy between the primary and secondary sides of the transformer (T1). It is desirable to optimize. It is preferable to apply a variable resistance as the impedance matching resistor R3.

If 8.45Ω is set as the impedance matching resistor (R3), an impedance matching (8Ω vs. 8Ω) is achieved between the primary coil (L1) and the secondary coil (L2) of the transformer (T1) to optimize energy transfer. In this case, the impedance of the transformer T1 on the secondary coil L2 side is 8.45//160 = 8Ω.)

As described above, in the crossover network 21 according to the second embodiment of the present invention, a plurality of outputs by the tap selector (SW) in consideration of the sound pressure difference between the low-range speaker 30 and the middle-high range speaker 40 Select one of the taps (T11-T15) and connect it to the mid-range speaker 40, and the impedance matching resistor(s) to achieve impedance matching between the primary coil (L1) and the secondary coil (L2) of the transformer (T1). By setting the resistance value of R3), it is possible to achieve a balance by removing the difference in sound pressure between the low and mid-range speakers.

The crossover network 21 according to the second embodiment is the same as in the first embodiment, as shown in FIG. 2, and is symmetrically based on the cutoff frequency fc, that is, the crossover frequency. Symmetric frequency division is performed.

The crossover frequency (fc) is determined by the inductance value of the primary coil (L1) of the primary side of the transformer (T1) and the impedance (R1) of the low-range speaker 30, and passed from the primary side to the low-frequency speaker 30. Audio signals (middle and high frequency) excluding the low frequency range are guided to the secondary secondary coil L2 of the transformer T1 and transmitted to the middle and high range speaker 40, so that interference does not occur in the multiway speaker.

4 is a circuit diagram showing a multiway speaker system including a crossover network divided into three frequency bands according to a third embodiment of the present invention.

Referring to FIG. 4, a multiway speaker system according to a third embodiment of the present invention includes a crossover network 22 that is divided into three frequency bands.

The crossover network 22 receives the audio signal power amplified by the power amplifier 10, divides it into three frequency bands, and then, a low-frequency speaker 31 for reproducing a low-frequency audio signal, and an intermediate frequency audio signal. It is applied to a midrange speaker 32 for reproducing a signal and a high-range speaker 33 for reproducing a high frequency audio signal.

The low-range speaker 31 for reproducing the low-frequency audio signal applies a woofer, and the midrange 32 for reproducing the mid-frequency audio signal is a squawker and a high-frequency audio signal. The high-frequency speaker 33 for this purpose may apply a tweeter.

The crossover network 22 according to the third embodiment of the present invention may be implemented using two first and second transformers T21 and T22.

The first transformer T21 has one end connected to the output terminal of the power amplifier 10 and wound on the core, and the other end connected to the input terminal of the low-frequency speaker 31 and the primary coil L1 and the primary coil. It includes a secondary coil L2, which is wound on the core so as to achieve a predetermined turn ratio n with L1, one end is grounded and the other end is connected to the primary coil L3 of the second transformer T22.

The second transformer T22 has one end connected to the output end of the secondary coil L2 of the first transformer T21, and the other end connected to the input end of the midrange speaker 32 after being wound on the core. (L3) and a secondary coil (L4) that is wound on the core to achieve a predetermined turn ratio (n) with the primary coil (L3), one end is grounded, and the other end is connected to the input terminal of the high-frequency speaker (33). do.

The crossover network 22 according to the third embodiment of the present invention passes through the primary coil L1 of the first transformer T21, as shown in FIG. 5A, while passing through the first cutoff frequency fc1, that is, The first frequency division is performed based on the first crossover frequency, so that the low-frequency audio signal is applied to the low-frequency speaker 31, and the audio signal (middle-high frequency) excluding the low-frequency audio signal is the secondary coil of the first transformer (T21). The audio signal of the middle and high frequency frequency is induced to L2 and separated by the secondary coil L2 of the first transformer T21 and is applied to the primary coil L3 of the second transformer T22.

The audio signal of the middle and high frequency frequency applied to the primary coil L3 of the second transformer T22 passes through the primary coil L3 of the second transformer T22, as shown in FIG. 5B. (fc2), that is, the second frequency division is performed based on the second crossover frequency so that the intermediate frequency audio signal is applied to the midrange speaker 32, and the high frequency audio signal excluding the intermediate frequency audio signal is the second transformer (T22). ) Of the secondary coil (L4), the second transformer (T22) of the secondary coil (L4) of the separated high-frequency audio signal is transmitted to the high-frequency speaker 33 is transmitted to the high-frequency speaker 33 Drive.

That is, the crossover network 22 according to the third embodiment of the present invention transmits the first cutoff frequency fc1 while passing through the primary coil L1 of the first transformer T21, as shown in FIG. 5A. After the first frequency division is performed on the basis of the low-frequency audio signal and the power amplified audio signal, the remaining bands excluding the low-frequency audio signal, that is, the audio signal of the medium and high-frequency frequencies, are separated, and the separated audio signals of the medium and high-frequency frequencies are shown in FIG. As shown, while passing through the primary coil L3 of the second transformer T22, the second cutoff frequency fc2, that is, the second frequency division is performed based on the second crossover frequency, so that the intermediate frequency audio signal And high-frequency audio signals.

The low-frequency audio signal output from the crossover network 22 is applied to the low-frequency speaker 31, the intermediate frequency audio signal is applied to the mid-range speaker 32, and the high-frequency audio signal is applied to the high-frequency speaker 33. do.

In this case, the first cutoff frequency fc1 is determined by the inductance value of the primary coil L1 of the first transformer T21 and the impedance R11 of the low-range speaker 31, and the second cutoff frequency ( fc2) may be determined by the inductance value of the primary coil L3 of the second transformer T22 and the impedance R12 of the midrange speaker 32.

In the above description of the embodiment, it is illustrated that the crossover network is divided into two or three frequency bands, but the present invention is not limited thereto and may be modified to divide the frequency into a plurality of frequency bands.

That is, the crossover network according to the present invention includes a plurality of transformers in which the output of the secondary coil of the front-end transformer is connected to the primary coil of the next-stage transformer, and the plurality of transformers are each input from the primary coil of the front-end transformer. The primary frequency of the low-frequency signal is separated from the signal, and the frequency signal of the remaining band is induced and separated by the secondary coil, and then the frequency signal of the remaining band is applied to the primary coil of the downstream transformer. Frequency division can be done.

In the above description of the embodiment, it has been illustrated that the frequency of the input signal from the output terminals of the primary coil and the secondary coil of the transformer provided in the crossover network is divided into a low-frequency signal and a high-frequency signal. Pass filters (LPF), high pass filters (HPF) and band pass filters (BPF) can be easily implemented.

In the present invention, a low-frequency signal and a high-frequency signal are divided with one transformer element, and a low-frequency signal is output from the output terminal of the primary coil of the transformer, and the high-frequency signal except for the low-frequency signal passing through the primary coil is accurate crossover. (crossover) A symmetrical high-frequency signal from which the low-frequency signal is omitted with the same slope is induced to the secondary coil to realize a perfect crossover.

The scope of the present invention is to be specified by the claims to be described later rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and the concept of equivalents thereof should be interpreted as being included in the scope of the present invention. .

The present invention can be applied to a crossover network capable of implementing accurate symmetric frequency division at a crossover point by eliminating a capacitor that adversely affects sound quality and employing only one transformer, and a multiway speaker system and audio system using the same.

10: power amplifier 20-22: crossover network
30, 31: low range speaker 32: mid range speaker
33: high-range speaker 40: mid-range speaker
L1,L3: primary coil L2,L4: secondary coil
R1,R2,R11-R13: Impedance R10: Resistance for impedance matching
SW: Tap selector T11-T15: Output tap
OT: output stage

Claims (12)

After receiving the audio signal, passing through the primary coil and separating it into two frequency bands of a low-frequency audio signal and a medium-high frequency audio signal based on a crossover frequency, the low-frequency audio signal is applied to a low-frequency speaker, and the medium-frequency audio signal Includes; a first transformer applied to the mid-range speaker,
The first transformer is
A primary coil having one end to which the audio signal is received is wound around a core and the other end connected to the input end of the low-range speaker; And
Crossover network comprising a; a secondary coil wound around the core, one end is grounded and the other end is connected to the input terminal of the middle and high frequency range speaker. The method of claim 1,
A plurality of output taps for attenuating the output of the secondary coil of the transformer to compensate for a difference in sound pressure between the low-pitched speaker and the mid-range speaker;
A tap selector configured to connect one of a plurality of output taps to a mid-range speaker in response to a difference in sound pressure between the low-pitched speaker and the mid-range speaker; And
The crossover network further comprising an impedance matching resistor inserted between the output terminal of the secondary coil and the ground to match the impedance between the primary coil and the secondary coil of the first transformer. The method of claim 2,
The difference in sound pressure between the low-range speaker and the mid-range speaker is one of -6db/oct, -8db/oct, -10db/oct, and -12db/oct. The method of claim 1,
The crossover frequency at which the frequency separation between the low frequency audio signal and the medium frequency audio signal is performed is a cutoff frequency determined by an inductance value of a primary coil of the first transformer and an impedance of a low frequency speaker. As the audio signal power amplified by the power amplifier passes through the primary coil, the first frequency is divided based on the first crossover frequency, so that the low-frequency audio signal is applied to the low-frequency speaker, and the audio of the mid-range frequency excluding the low-frequency audio signal A first transformer, wherein the signal is guided to the secondary coil of the first transformer, and is guided to the secondary coil of the first transformer to generate an audio signal of a separated medium and high frequency frequency; And
After the audio signal of the mid-range frequency is applied to the primary coil, the secondary frequency is divided based on the second crossover frequency while passing through the primary coil, so that the intermediate frequency audio signal is applied to the midrange speaker, and the intermediate frequency audio A crossover network comprising: a second transformer in which the high frequency audio signal excluding the signal is guided to the secondary coil, and the audio signal of the high frequency frequency separated by being guided to the secondary coil is applied to the high frequency speaker. The method of claim 5,
The first transformer has one end connected to the output terminal of the power amplifier and wound on the core, and the other end is connected to the input terminal of the low-range speaker, and the primary coil is wound on the core, and one end is grounded and the other end is 1 of the second transformer. It includes a secondary coil connected to the primary coil,
The second transformer has one end connected to the output terminal of the secondary coil of the first transformer and wound on the core, and the other end is wound on the primary coil and the core connected to the input terminal of the midrange speaker, and one end is grounded and the other end A crossover network including a secondary coil connected to the input terminal of the high-frequency speaker. The method of claim 5,
The first crossover frequency fc is a crossover network obtained by Equation 1 below.
[Equation 1]

Here, R is the impedance of the low-range speaker and L is the inductance of the primary coil. Includes a plurality of transformers in which the output of the secondary coil of the previous transformer is connected to the primary coil of the next transformer,
In each of the plurality of transformers, the primary frequency of the low-frequency signal is separated from the input signal from the primary coil of the front-end transformer, and the frequency signals of the remaining bands are induced and separated by the secondary coil, and then the frequency signals of the remaining bands are rearranged. A crossover network in which frequency is divided into a plurality of frequency bands in a manner applied to the primary coil of a transformer. Applying an input signal to be frequency-divided to an input terminal of the primary coil of the transformer;
Passing through the primary coil, separating a low frequency signal from an input signal from an output terminal of the primary coil and outputting the low frequency signal to a low-frequency speaker; And
Inducing and separating the middle and high frequency signals of the remaining bands except for the low frequency signal to the secondary coil of the transformer, and outputting them to a middle and high frequency speaker; including,
The frequency division method of a crossover network in which the low frequency signal is separated based on a cutoff frequency (fc) determined by an inductance value of a primary coil of a transformer and an impedance of a low frequency speaker. Bass speaker;
Midrange speakers;
Treble speakers;
A first transformer for receiving the audio signal and separating it into two frequency bands of a low frequency audio signal and a medium frequency audio signal, applying the low frequency audio signal to the low frequency speaker, and outputting the medium frequency audio signal; And
After receiving the middle frequency audio signal, the intermediate frequency audio signal and the high frequency audio signal are separated into two frequency bands, and the intermediate frequency audio signal is applied to the midrange speaker and the high frequency audio signal is applied to the high frequency speaker. Multi-way speaker system including; 2 transformers. The method of claim 10,
A low-frequency audio signal is separated from the audio signal received from the output terminal of the primary coil while passing through the primary coil of the first transformer, and the first frequency is divided based on the first cutoff frequency, and the received audio signal The remaining medium and high frequency audio signals excluding the low frequency audio signal from are guided to the secondary coil of the first transformer and separated,
The separated middle frequency audio signal passes through the primary coil of the second transformer, and the intermediate frequency audio signal is separated from the output terminal of the primary coil of the second transformer, and the second frequency is divided based on the second cutoff frequency. And the high frequency audio signals other than the intermediate frequency audio signal separated from the middle frequency audio signal are guided to and separated from the secondary coil of the second transformer. A power amplifier that power-amplifies the audio signal;
Bass speaker;
Midrange speakers;
Treble speakers;
A first transformer for receiving the power-amplified audio signal and separating it into two frequency bands of a low frequency audio signal and a medium frequency audio signal, applying the low frequency audio signal to the low frequency speaker and outputting the medium frequency audio signal; And
After receiving the middle frequency audio signal, the intermediate frequency audio signal and the high frequency audio signal are separated into two frequency bands, and the intermediate frequency audio signal is applied to the midrange speaker and the high frequency audio signal is applied to the high frequency speaker. Audio system including; 2 transformers.

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