JPH0539097U - Channel Day Diva - Google Patents

Abstract

(57) [Abstract] [Purpose] The characteristics at the crossover part of each band divided by the channel divider, such as cutoff frequency,
Easily perform slope characteristics with simple operations. [Configuration] During adjustment, the test tone signal output from the test tone generator 12 is supplied to the DSP 16 by the changeover switch 10. Then, the output switches 26A to 26D are turned ON manually or automatically, and the test tone is reproduced by the speaker only in the required band. In this state, when the cutoff frequency or slope characteristic in the crossover portion of each band is instructed by the operation / display unit 30, the DSP 16 outputs the test tone signal of the corresponding characteristic via the CPU 28. The user repeats such adjustment work to obtain desired characteristics.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a multi-speaker system in which reproduction is performed by a plurality of speakers, and more particularly, it relates to improvement of a channel divider that performs frequency division for outputting a signal in a frequency band corresponding to each speaker.

[0002]

[Prior Art]

 In some audio devices, for example, low-range, mid-range, and high-range speakers are provided, and a playback signal is divided into bands corresponding to the speakers by a channel divider. It is a system for playing. In such a system, the crossover frequency and cut-off slope characteristics of each channel can be set according to the playback bandwidth of each speaker and user preference.

Conventionally, such adjustment work is performed using a music source such as a tape or a CD. That is, the coordinator first plays an appropriate music source. Then, the audio signal of the music source is reproduced and output from each speaker. The adjuster operates a switch for adjustment or the like while listening to the reproduced sound to obtain a desired characteristic.

[0004]

[Problems to be solved by the device]

 However, in such a conventional technique, the frequency component and the volume of each band of the music source being reproduced change every moment. Further, it is preferable that only the sound of the speaker in any two bands, for example, the middle band and the high band is usually reproduced at the time of adjustment, but the sound of all bands included in the music source is reproduced. Therefore, (1) selection of crossover frequency between bands and selection of cutoff slope characteristics (2) phase selection of each band with respect to the reference band is very difficult.

In particular, in an audio device for a car (so-called car stereo), the speaker cannot be arranged at the same position as seen by the listener. For example, as shown in FIG. 6, the high-frequency speaker SPA is arranged in the front position, the middle-frequency speaker SPB is arranged in the side position, and the low-frequency speaker SPC is arranged in the back position.

Here, since it is considered that the normal driver D has the highest chance to enjoy the audio device, the driver D is mainly considered. First, considering the phase between the reproduced sounds of the mid-range speaker SPB and the low-range speaker SPC, the phases of the reproduced sounds at the crossover frequencies reproduced by both speakers are shown by the solid lines in FIGS. 7 (A) and 7 (B). If so, it becomes in-phase, but if it becomes a dotted line, it becomes in-phase. Further, since the wavelength of the reproduced sound of the crossover frequency becomes sufficiently longer than each distance from the driver D to both speakers, the phase relationship of each speaker input becomes a phase relationship which almost reaches the ear of the driver D.

For example, consider the phase between the reproduced sounds of the mid-range speaker SPB and the low-range speaker SPC. Assuming that the crossover frequency is 100 Hz, one wavelength is 340 m × (1/100) = 3.4 m .................... (1).

On the other hand, regarding the phase between the reproduced sounds of the high-frequency speaker SPA and the mid-frequency speaker SPB, assuming that the crossover frequency is 5 KHz, one wavelength is 340 m × (1/5000) = 0. 068m = 6.8cm (2) Therefore, in this case, even if the input sides of both speakers are in phase, if the distances from them to the driver D are different, they will not necessarily be in phase. Therefore, it is also necessary to adjust the phase at the crossover frequency part in the mid-high band. However, such adjustments are generally very difficult and require considerable skill.

The present invention focuses on these points, and provides a channel divider capable of easily performing characteristics such as cutoff frequency, slope characteristic, and phase selection at the crossover portion of each band by a simple operation. That is the purpose.

[0010]

[Means for Solving the Problems]

 One aspect of the present invention has characteristic setting means for dividing a reproduced signal into a plurality of frequency bands corresponding to the electroacoustic conversion means and setting the characteristics at the crossover portion of each band at this time as desired. In the channel divider, a test tone generating means for outputting a test tone signal to the characteristic setting means, and a test tone signal in a desired band among the test tone signals band-divided by the characteristic setting means are selected and the corresponding electrical signals are selected. And a test tone output means for outputting to the sound converting means.

According to another invention, the test tone generating means, an adjustment target selecting means for selecting a crossover portion to be adjusted, and a test tone signal in a band corresponding to the crossover portion selected thereby are automatically generated. And a test tone automatic output means for selectively outputting to a corresponding electro-acoustic conversion means.

[0012]

[Action]

 According to the invention, a test tone generating means is provided for the adjustment. Then, by using the test tone thus obtained, the cutoff frequency and slope characteristics at the crossover portion are adjusted. At this time, it is possible to manually select which band to output the test tone, but it is automatically determined by selecting the adjustment target.

[0013]

【Example】

 Hereinafter, an embodiment of a channel divider according to the present invention will be described with reference to the accompanying drawings. The same reference numerals are used for the same or corresponding components as those of the conventional example described above.

FIG. 1 shows the configuration of the channel divider according to this embodiment. In the figure, source signals such as tape, CD, and radio are input to one of the changeover terminals of the changeover switch 10. The output side of the test tone generator 12 is connected to the other switching terminal side of the changeover switch 10. The common terminal side of the switching switch 10 is connected to the input side of a DSP (Digital signal processor) 16 via an A / D converter 14.

A RAM 18 is connected to the DSP 16, and output sides thereof are connected to input sides of the digital filters 20A to 20D, respectively. D / A converters 22A to 22D, analog filters 24A to 24D, and output switches 26A to 26D are connected in series to the output sides of these digital filters 20A to 20D, respectively. Speakers for each band are connected to the output switches 26A to 26D. It should be noted that these speakers are arranged in the automobile as shown in FIG. 6, for example. Next, a CPU 28 is connected to the changeover switch 10, the DSP 16, and the output switches 26A to 26D, and an operation / display unit 30 is connected to the CPU 28.

Of the above-mentioned units, the operation / display unit 30 has a structure as shown in FIG. 2, for example. In the figure, first, on the display unit 30A, as shown in the figure, the frequency characteristics of the gain in each band of bass (SU BWOOFER), middle bass (LOW), middle tone (MID), and treble (HIGH) are displayed. Schematic graphs 300, 302, 304 and 306 are shown respectively. Further, in these graphs, the interruption slopes 308, 310, 312 are displayed, and for example, in the case of -18 dB / oct, "18" is displayed.

Further, crossover frequency displays 314, 316, and 318 are respectively performed in the lower part of the above display. In these displays, "LP" is an abbreviation for a low-pass filter and indicates the crossover frequency in the high-frequency slope in each band, and "HP" is an abbreviation for a high-pass filter in which the cross-over frequency for the low-frequency slope in each band is indicated. Show.

Further, speaker output and delay time display 320, input level display 322, output mode display 324, and test tone output display 326 are displayed below the respective displays. ing.

Next, the operation unit 30B will be described. The switch 330 is for designating an operation target such as volume and phase. The switch 332 is for selecting a band to be adjusted. The switch 334 is for increasing or decreasing the operation target specified by the switch 330, for example, the volume in the band specified by the switch 332.

Next, the switch 336 is used to manually specify the speaker to which the test tone is output in order to adjust the crossover frequency of each band, the cutoff slope characteristic, the phase selection, and the level of each band. Is used for. The switch 338 is for adjusting the frequency and slope of the high-pass and low-pass filters in each band. When all the output selection switches 336 are off, the test tone is automatically output from the speaker in the band being adjusted and the band crossing the band being adjusted. For example, when adjusting a low-pass filter in the mid- and low-frequency range, a test tone is output for the mid-range as well.

As described above, the adjustment / selection work is divided into the combination of the switches 330 and 332 and the combination of the switches 338 and 340. This is to prevent the loudspeaker from being operated and being destroyed. This is because the speaker may be destroyed if a signal with a frequency lower than the predetermined band is input.

The switch 340 is for instructing an adjustment target, and the adjustment amount can be increased or decreased by the switch 334. The switch 342 is for manually outputting the test tone, and its volume is adjusted by the volume 344. Besides, the volume 346 is for adjusting the source input level from the outside, and the switch 348 is for selecting the bass reproduction mode. In this bass playback mode, when only one subwoofer is used, it is necessary to output sound from both L and R channels from the speaker, but when two are used, each L and R channel is used. To play in stereo mode.

Next, the CPU 28 has a function as shown in FIG. 3, for example. In the figure, the operation / display unit 30 described above is connected to the operation mode determination unit 28A. The operation mode determination unit 28A determines the operation mode corresponding to the switch operated by the operation / display unit 30. The operation determined here is output to each of the input switching control unit 28B, the characteristic setting unit 28C, and the output control unit 28D according to its content.

The input changeover control unit 28B has a function of changing over the changeover switch 10 based on the input data. The characteristic setting unit 28C has a function of instructing the characteristic setting and each band level in the DSP 16 based on the input data. Further, the output control unit 28D has a function of turning ON / OFF the output switches 26A to 26D based on the input data. Further, data, programs or work areas necessary for the operation of each part are stored or expanded in the memory 28E.

Next, the test tone generator 12 is provided for characteristic adjustment, and has a function of generating test tones such as pink noise and white noise in the entire band from low to high frequencies. Have. The DSP 16 has a function of dividing an input signal into each band and outputting it based on a cutoff frequency, a slope characteristic and a level set by an instruction from the CPU 28. At this time, the RAM 18 is used as needed. In this embodiment, the band is divided into four bands of low band, middle low band, middle band and high band.

Next, the digital filters 20A to 20D are provided for the purpose of improving the conversion accuracy into analog signals and reducing the order of the analog filters 24A to 24D. The analog filters 24A to 24D are provided to remove noise of a high frequency above the audible band included in the input signal. The output switches 26A to 26D are for selectively outputting any of the bands.

Next, the operation of the present embodiment configured as described above will be described with reference to the frequency characteristic of FIG. 4 and the flowchart of FIG. In the following description, the case of adjusting the slope characteristic between the mid-low range and the mid-range using the mid-low range as a reference for adjustment will be described as an example. The flowchart of FIG. 5 is executed as part of the entire operation.

<Rough Adjustment> First, rough adjustment is performed. This is done to prevent the speaker from being destroyed by the low-frequency signal described above, and the crossover frequency recommended by the manufacturer of the speaker is set without outputting the sound.

Explaining the specific procedure, the coordinator operates the switch 342 (see FIG. 2) to light “OFF”, and operates the knob 346 to the minus side to output audio from any speaker. There is no state. Next, while operating the switch 338, select a filter to light its display, and operate the "FR EQ" switch 340 and the switch 334 up or down to recommend the cutoff frequency. Set to the value. At this time, the type of the filter and the value of the frequency are respectively displayed in the corresponding portions of the displays 314, 316, 318. Such a switch operation is performed for each filter, that is, each slope.

The data input by this operation is input to the operation mode determination unit 28A (see FIG. 1) of the CPU 28, and the characteristic setting unit 28C sets those characteristics in the DSP 16, that is, the recommended cutoff frequency of each speaker. Will be.

<Main Adjustment> a, When a Test Tone is Manually Output Next, the operation of the main adjustment will be described. Due to the characteristics of the speakers to be combined and the mounting conditions, the recommended conditions by the above-mentioned rough adjustment are not always the best. For this reason, main adjustments are made to obtain the desired characteristics by slightly changing the characteristics around the manufacturer's recommended values.

First, a case where the test tone is manually output to perform the main adjustment will be described. First, the necessary one of the switches 336 of the operation unit 30B is operated by the adjuster. For example, the buttons in the middle low range (LOW) and middle range (MID) are operated. Then, these switch operations are determined by the operation mode determination unit 28A of the CPU 28, and it is determined that the automatic mode is not selected in step SA of FIG. At the same time, the output control unit 28D controls the output switches 26B and 26C to turn on. Along with this, the display unit 30A displays the middle and low frequencies and the portions 302 and 304 corresponding to the middle frequency range.

Next, when the switch 342 is operated to instruct the output of test tones for the left and right, for example, the operation mode determination unit 28A makes a determination in the same manner, and the input switching unit 28B tests the changeover switch 10. It is switched to the tone generator 12 side. As a result, the test tone signal output from the test tone generator 12 is converted into a digital signal by the A / D converter 14 and then supplied to the DSP 16. The DSP 16 band-divides the input test tone signal and outputs it.

The test tone signals of each band are output to the output switches 26A to 26D after the processing such as the above-mentioned noise removal by the digital filters 20A to 20D, the D / A converters 22A to 22D, and the analog filters 24A to 24D. Each is output. However, since only the output switches 26B and 26C are turned on, the test tone signal is output only in the low and middle frequencies. At the same time, a display 326 to that effect is made.

The strength of the test tone output from the mid-low range and mid-range speakers is adjusted by turning the knob 344. That is, the operation of the knob 344 is determined by the operation mode determination unit 28A, and the output level characteristic of the DSP 16 is adjusted by the characteristic setting unit 28C. At the same time, an output level display 320 from the speaker is performed. At the same time, the phase of the test tone is also displayed as time (mS).

Next, the switch 338 is operated to select the slope to be adjusted, that is, the filter. For example, when adjusting the slope SL3 (see FIG. 4), the switch 338 is pressed to select "LOW LP". Then, “LP” on the display 316 lights up, the value of the recommended cutoff frequency set by the rough adjustment is displayed, and the slope SL3 on the display 302 also blinks.

Next, the coordinator presses the button “FREQ” of the switch 340 and further instructs the switch 334 to go up or down. As a result, the cutoff frequency of the slope SL3 in the DSP 16 is raised or lowered by the characteristic setting unit 28C, and the changed value is displayed on the display 316. Then, the test tone with the set characteristics comes to be output from the speaker, and the cutoff frequency is provisionally set.

After that, the coordinator presses the button “SLOP E” of the switch 340 while listening to the test tone. Then, whichever of “12” and “18” is set in the display 310 blinks. Here, when the switch 334 instructs up or down, the other one blinks and the characteristic setting unit 28C of the CPU 28 sets the characteristic of the DSP 16. When any one of them is selected and the switch 338 is pressed, the blinking of the switch illuminates and the characteristic setting of the slope SL3 is completed. By repeating the same operation, the characteristics are set on the slope SL4, that is, on the high-pass filter side in the middle range.

Next, the switch 330 is pressed to make “LEVEL” blink, and the “MID” of the switch 332 is pushed so that it blinks. Then, the switch 334 is used to raise or lower the output level of the midrange speaker. Next, the switch 330 is pressed again to bring the “+” of the display 304 into a blinking state, and the switch 334 selects either + or −. This code indicates the phase state (see FIG. 7). These processes are similarly performed by the characteristic setting unit 28C. By repeating the above operation, the cutoff frequency, the slop characteristics, and the output level of each band are adjusted.

B, When the test tone is automatically output In this case, when the manual switch 336 in the operation unit 30B is turned off and the switch 338 is operated, the operation mode determination unit 28A operates as shown in FIG. It is determined that the operation mode is automatic as shown in step SA of step S3, and the automatic selection operation shown in FIG.

For example, when “LOW LP” is selected by the switch 338 (see step S E in the figure), this switch operation is determined by the operation mode determination unit 28A of the CPU 28, and the output control unit 28D outputs the output switch 26B. , 26C is controlled to be ON. Then, when the switch 342 is not "OFF", the test tones are output in the middle low range and the middle range (see step SG in the same figure). Along with this, the display section 30A displays 302, 304 of the middle low range and the part corresponding to the middle range. When the switch 342 is "OFF", input sources such as CD and tape are output in those bands.

The same applies to other cases, and the test tones in the band corresponding to the slope selected by the switch 338 are output by the operations of the operation mode determination unit 28A and the output control unit 28D of the CPU 28, respectively.

That is, when SL1 (low-range LPF) and SL2 (medium-low range HPF) are selected as slopes to be adjusted by operating the switch 338 (steps SB, SC), low-range and middle-low range are selected. A test tone is output (step SD). When slopes SL5 (LPF in the middle range) and SL6 (HPF in the high range) are selected (steps SH and SI), test tone output in the high range and the middle range is performed (step SJ).

The subsequent operation is the same as in the case of the above-mentioned manual. When the switch 336 is pressed during the above automatic operation mode, the manual operation mode is entered and the test tone output of the corresponding band is performed.

As described above, the present embodiment has the following effects. (1) Since the test tone generator 12 suitable for adjustment is built-in, it is easy to judge the audibility during adjustment. (2) Since the test tone is not output in the band other than the band to be adjusted, the audibility judgment becomes easier. (3) Since the test tone output can be automatically selected, the labor for operation is saved.

It should be noted that the present invention is not limited to the above-described embodiments at all, and includes, for example, the following ones. (1) The present invention is suitable for car stereos where it is difficult to arrange speakers at the same position, but it is also applicable to ordinary home audio devices, television audio devices, and the like. (2) Although the frequency band is divided into four in the above embodiment, it may be divided into two or more desired numbers. Further, although the middle and low frequencies are used as the reference, other bands may be used as the reference. (3) Although the DSP is used in the above-described embodiment, a circuit configuration having another similar operation may be used. Further, the mode of the operation / display unit 30 is also arbitrary, and for example, a switch for mode switching between manual and automatic may be provided.

[0047]

[Effect of the device]

 As described above, the channel divider according to the present invention has the following effects. (1) Since the test tone generating means is provided and the test tone output is performed only for the required band to perform the adjustment work, the characteristic of the crossover portion of each band can be easily performed by a simple operation. There is. (2) In particular, according to the invention as set forth in claim 2, the output band of the test tone is automatically set, so that there is an effect that labor for adjustment operation can be saved.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a channel divider according to the present invention.

FIG. 2 is an explanatory diagram showing an example of an operation / display unit of the embodiment.

FIG. 3 is a block diagram showing functions of a CPU in the embodiment.

FIG. 4 is a graph showing frequency characteristics of each band to be adjusted.

FIG. 5 is a flowchart showing an operation in the automatic mode.

FIG. 6 is an explanatory diagram showing an arrangement example of speakers in an automobile.

FIG. 7 is a graph showing a phase relationship between speaker outputs.

[Explanation of symbols]

10 ... Changeover switch, 12 ... Test tone generator (test tone generating means), 14 ... A / D converter, 16 ... DS
P (characteristic setting means), 18 ... RAM, 20A to 20D ...
Digital filter, 22A to 22D ... D / A converter,
24A to 24D ... Analog filter, 26A to 26D ...
Output switch (test tone output means, test tone automatic output means), 28 ... CPU, 28A ... Operation mode determination section, 28B ... Input switching control section, 28C ... Characteristic setting section, 2
8D ... Output control unit (test tone automatic output means), 28
E ... Memory, 30 ... Operation / display section, 30A ... Display section, 3
0B ... Operation unit, 300 to 326 ... Display, 336 ... Switch (test tone output means), 338 ... Switch (adjustment target selection means), F1 to F3 ... Cutoff frequency, SL1 to S
L6 ... Slope characteristics, SPA to SPC ... Speaker (electroacoustic conversion means).

Claims (2)

[Scope of utility model registration request] 1. A channel divider having characteristic setting means for dividing a reproduced signal into a plurality of frequency bands corresponding to electro-acoustic conversion means and setting characteristics at a crossover portion of each band at this time as desired. , A test tone generating means for outputting a test tone signal to the characteristic setting means, and a test tone signal of a desired band among the test tone signals band-divided by the characteristic setting means are selected and the corresponding electroacoustic conversion is performed. A channel divider comprising a test tone output means for outputting to the means. 2. A channel divider having a characteristic setting means for dividing a reproduced signal into a plurality of frequency bands corresponding to the electroacoustic converting means, and for setting a characteristic at a crossover portion of each band at this time as desired. , A test tone generating means for outputting a test tone signal to the characteristic setting means, an adjustment target selecting means for selecting a crossover portion to be adjusted, and a test tone signal in a band corresponding to the crossover portion selected by the adjustment target selecting means. And a test tone automatic output means for automatically selecting and outputting to a corresponding electro-acoustic conversion means.