JP4279210B2 - High frequency signal output delay time adjustment device - Google Patents

Description

  The present invention relates to an adjustment device that adjusts a shift in sound image localization due to a difference in distance from a plurality of speakers to a listening position, and in particular, a high frequency band that adjusts a shift in sound image localization due to sound emitted from a high-frequency reproduction dedicated speaker. The present invention relates to a dedicated signal output delay time adjusting device.

  In a so-called multi-way audio system that combines a plurality of speakers such as 2-way (3-way) and 3-way (3-way), in order to play music that does not feel uncomfortable for the listener, at the listening position of the sound emitted from each speaker It is necessary to match the arrival time, and conventionally, a listening position automatic correction device disclosed in Japanese Patent No. 3148060 has been proposed.

  This listening position automatic correction device is provided with a delay device that delays an audio signal and supplies it to each speaker in order to match the arrival time of the sound emitted from each speaker at the listening position, and the delay time of each delay device. The amount is set by the following method.

  First, an impulse response as shown in FIG. 4 of the same publication was measured by emitting sound by supplying an M-sequence signal to a specific speaker and picking up the sound with a microphone provided at the listening position. Thereafter, a peak value of the impulse response is detected, and a value obtained by multiplying the peak value by a predetermined constant k is set as a threshold. Next, the rising point of the impulse response that first exceeds the threshold is detected, and the time from when the M-sequence signal is input to the speaker to the rising point is obtained as the sound propagation delay time.

  Then, the propagation delay time of the sound from the remaining speakers to the listening position is obtained by the same processing, and the delay time amount of each delay device provided on the input side of each speaker is calculated based on each propagation delay time. I am going to set it.

Japanese Patent No. 3148060

  By the way, in the conventional listening position automatic correction device disclosed in Japanese Patent No. 3148060, as described above, the time when the sound reaches the rising point of the impulse response that first exceeds the threshold obtained from the peak value of the impulse response. As the time point, the propagation delay time to the listening position of the sound emitted from each speaker is obtained, and the delay time amount of the delay device for delaying the audio signal is set.

  However, in a limited space such as in the interior of a car, for example, the sound emitted from the speaker becomes reflected sound and enters the microphone for sound collection, or ambient noise enters the microphone. Even if the delay time amount of the delay device is set according to the propagation delay time obtained from the rise time of the impulse response that first exceeds the threshold, it is difficult to localize the sound image without giving the listener a sense of incongruity There's a problem.

  In particular, in the case of a high frequency sound emitted from a high frequency reproduction speaker such as a tweeter, the influence of the reflected sound becomes large. Therefore, the impulse response rise time point that first exceeds the above threshold is used as a reference. Therefore, there is a problem that it is difficult to obtain a delay time amount for localizing a high-frequency sound image without giving the listener a sense of incongruity.

  The present invention has been made in view of such conventional problems, and a high-frequency dedicated signal output delay time for localizing a sound image without giving a sense of incongruity to a listener for a high-frequency sound emitted from a high-frequency reproduction dedicated speaker. It is an object of the present invention to provide an adjustment device and a high frequency dedicated signal output delay time adjustment method.

  The invention according to claim 1 is a high-frequency dedicated signal output delay time adjusting device for localizing a sound image at a listening position of sound emitted from a plurality of high-frequency reproduction dedicated speakers, which is supplied from a signal source. Delay means for delaying a dedicated signal based on the amount of delay time and supplying the dedicated signal to the high frequency reproduction speaker, measurement signal generating means for supplying a measurement signal to the high frequency reproduction dedicated speaker, and the measurement signal A sound collecting means for picking up the measurement sound emitted from the high-frequency reproduction dedicated speaker and outputting a detection signal, and a delay time amount of the delay means based on the detection signal output from the sound collecting means. A delay time calculating means for calculating and setting, wherein the delay time calculating means detects a first occurrence time and a maximum amplitude value at which the amplitude of the detection signal is maximum, and is used for the high-frequency reproduction speaker. Next, the detection is performed within the range between the time when the measurement signal is supplied and the first generation time and within the range between the maximum amplitude value and a level value set lower than the maximum amplitude value by a predetermined level. The delay time is detected based on a propagation delay time from the time when the measurement signal is supplied to the high frequency reproduction speaker to the second occurrence time when the second occurrence time at which the amplitude of the signal is maximized is detected. It is characterized by calculating a quantity.

  The invention according to claim 5 is a high frequency signal output delay time adjusting method for localizing a sound image at a listening position of sound emitted from a plurality of high frequency reproduction dedicated speakers, wherein the high frequency signal is supplied from a signal source. A delay step of delaying a dedicated signal based on a delay time amount and supplying the dedicated signal to the high-frequency playback speaker; a measurement signal generating step of supplying a measurement signal to the high-frequency playback speaker; and the measurement signal A sound collecting step for collecting measurement sound emitted from the high-frequency reproduction dedicated speaker and outputting a detection signal, and a delay time calculating step for calculating and setting the delay time amount based on the detection signal; The delay time calculating step detects a first occurrence time and a maximum amplitude value at which the amplitude of the detection signal is maximum, and at the time when the measurement signal is supplied to the high-frequency reproduction speaker. The second generation in which the amplitude of the detection signal becomes the next maximum within the range of the generation time of 1 and within the range of the maximum amplitude value and the level value set lower than the maximum amplitude value by a predetermined level. Detecting the time, and calculating the amount of delay time based on propagation delay time from the time when the measurement signal is supplied to the high frequency reproduction dedicated speaker to the first and second generation times. To do.

  According to a sixth aspect of the present invention, there is provided a program in a high-frequency dedicated signal output delay time adjustment apparatus for processing a sound image localization process at a listening position of sound emitted from a plurality of high-frequency reproduction dedicated speakers by a computer. A delay step for delaying a high-frequency dedicated signal supplied from a delay time amount and supplying the signal to the high-frequency reproduction dedicated speaker; and a measurement signal generating step for supplying a measurement signal to the high-frequency reproduction dedicated speaker; Collecting a measurement sound emitted from the high-frequency reproduction speaker based on the measurement signal and outputting a detection signal; and calculating and setting the delay time amount based on the detection signal A delay time calculating step, wherein the delay time calculating step detects a first occurrence time and a maximum amplitude value at which the amplitude of the detection signal is maximum. Further, a level value that is within a range between the time point when the measurement signal is supplied to the high-frequency reproduction speaker and the first generation time, and is set lower than the maximum amplitude value and the maximum amplitude value by a predetermined level. Next, the second generation time in which the amplitude of the detection signal is maximized is detected and the measurement signal is supplied to the high frequency reproduction speaker, and then the first and second generations are performed. The delay time amount is calculated based on a propagation delay time up to time.

  The invention according to claim 7 is an information recording / reproducing medium, wherein the program according to claim 6 is recorded.

  A high-frequency dedicated signal output delay time adjusting apparatus according to an embodiment of the present invention will be described with reference to FIG.

  FIG. 1A is a block diagram showing the configuration of the high-frequency dedicated signal output delay time adjusting apparatus of this embodiment, and FIGS. 1B, 1C, and 1D are waveform diagrams for explaining the operation thereof. It is.

  In FIG. 1A, this high-frequency dedicated signal output delay time adjusting device 1 includes a delay unit A, a measurement signal generating unit B, a delay time calculating unit C, a switching unit SW, and sound collection means provided at a listening position. As a microphone D.

  The delay unit A delays the high frequency dedicated audio signal (hereinafter referred to as “source signal”) supplied from the signal source E by a predetermined delay time amount, and the delayed signal is switched to the high level via the switching unit SW. The audio signal for driving the sound range (hereinafter referred to as “drive signal”) is supplied to a speaker dedicated to high frequency reproduction such as a tweeter.

  For example, as illustrated in FIG. 6A, a high-frequency reproduction dedicated speaker such as a tweeter provided in each of a plurality of speaker units SPU1, SPU2, etc. constituting a 2-way, 3-way, etc. multi-way speaker system. When driving TW1, TW2, etc., the delay unit A delays the source signals Sin1, Sin2, etc. supplied from the signal source E by a predetermined delay time amount DLY1, DLY2, etc., and drives the delayed high sound range. The signals S1, S2, etc. are supplied to the high frequency reproduction dedicated speakers TW1, TW2, etc. via the changeover switches SW1, SW2, etc. in the changeover unit SW.

  Note that the high-frequency dedicated signal output delay time adjusting apparatus 1 of the present embodiment is not limited to driving the two high-frequency reproduction dedicated speakers TW1 and TW2, but for convenience of explanation, the high-frequency reproduction dedicated speaker TW1. , TW2 will be described below.

  The measurement signal generator B generates a measurement signal St having a predetermined waveform in which power is concentrated in the high sound range on the frequency axis. For example, as a measurement signal St whose power is concentrated in the high sound range, a signal having a single waveform corresponding to one period τ of a sine wave having a frequency of about 11 kHz is generated as illustrated in FIG. When the measurement signal generator B performs processing for setting the delay time amounts DLY1 and DLY2 of the delay unit A, the measurement signal St is sent to the high level via the changeover switches SW1 and SW2 in the switching unit SW. Is supplied to the TW1 and TW2 dedicated speakers.

  As described above, the switching unit SW includes the changeover switches SW1 and SW2. Then, when the selector switches SW1 and SW2 are switched to the delay unit A side, when output from the delay unit A, the drive signals S1 and S2 are supplied to the high-frequency reproduction dedicated speakers TW1 and TW2, and a measurement signal is generated. By switching to the part B side, the measurement signal St is supplied to the high-frequency reproduction dedicated speakers TW1 and TW2.

  The delay time calculation unit C is provided to set the delay time amounts DLY1, DLY2 of the delay unit A. That is, the measurement signal St is supplied from the measurement signal generation unit B to each of the high-frequency reproduction dedicated speakers TW1 and TW2 via the switching unit SW, and the microphone D collects the measurement sound generated by the measurement signal St. When the detection signal Sm is obtained, the delay time calculation unit C analyzes each detection signal Sm so that each measurement sound emitted from the high-frequency reproduction dedicated speakers TW1 and TW2 arrives at the listening position. The delay times DLY1 and DLY2 to be set in the delay unit A are calculated based on the propagation delay times.

  Next, the operation of the high-frequency dedicated signal output delay time adjusting apparatus 1 having such a configuration will be described. A case will be described in which two high-frequency reproduction dedicated speakers TW1 and TW2 illustrated in FIG. 1A are driven.

  First, the operation of the delay unit A when setting the delay time amounts DLY1, DLY2 will be described.

  The measurement signal generator B, the delay time calculation unit C, and the switching unit SW start operation synchronously, and the measurement signal generation unit B transmits the measurement signal St to the high frequency reproduction dedicated speaker TW1 via the switch SW1. To generate a measurement sound, and a detection signal Sm obtained when the microphone D picks up the sound is output to the delay time calculation unit C and held in a storage unit (not shown).

  Thereby, the delay time calculation unit C inputs a detection signal Sm corresponding to an impulse response as schematically shown in FIG. 1C, for example, with respect to the measurement signal St as shown in FIG. Hold.

  Next, the delay time calculation unit C detects the peak value of the maximum amplitude Pmx of the held detection signal Sm, thereby detecting the generation time (hereinafter referred to as “first generation time”) tc of the maximum amplitude Pmx. Thereby, the delay time calculation unit C, as illustrated in FIG. 1C, is the time when the measurement signal generator B supplies the measurement signal St to the high frequency reproduction dedicated speaker TW1 (that is, the time 0). As a reference, the first occurrence time tc is detected.

  Further, the delay time calculation unit C calculates a level value Lth that is several tens of percent (that is, 20 to 30%) less than the maximum amplitude Pmx detected at the peak value, and calculates the level value Lth and the maximum amplitude Pmx. The next maximum amplitude Pfw occurring within the level range Wth between and at a time earlier than the first generation time tc is detected, and the generation time of the maximum amplitude Pfw (hereinafter referred to as “second time”) is detected. Tfw) is detected.

  In addition, the ratio (Wth × 100 / Pmx) of the level range Wth with respect to the above-mentioned maximum amplitude Pmx is determined according to human auditory characteristics, and as described above, by setting the ratio to several tens of percent, It is possible to detect the second occurrence time tfw in accordance with human auditory characteristics.

  When the second generation time tfw is detected, from the time when the measurement signal St is supplied from the measurement signal generator B to the high-frequency reproduction dedicated speaker TW1 (that is, at time 0) to the second generation time tfw. Is the sound propagation delay time τi (symbol i is the identification number of the high-frequency reproduction dedicated speaker).

  Further, as a result of performing processing for detecting another maximum amplitude Pfw existing at a time ahead of the first generation time tc, the delay time calculation unit C shows the detection signal Sm illustrated in FIG. If the second generation time cannot be detected because the waveform does not have the maximum amplitude within the level range Wth, the first generation is started from time 0. The period up to time tc is defined as the sound propagation delay time τi.

  Next, the measurement signal generator B, the delay time calculation unit C, and the switching unit SW perform the same processing for the high-frequency reproduction dedicated speaker TW2 as in the case of the high-frequency reproduction dedicated speaker TW1, and the measurement signal The measurement signal St is supplied from the generator B to the high frequency reproduction speaker TW2, and the delay time calculation unit C calculates the detection signal Sm output from the microphone D, thereby releasing the high frequency reproduction speaker TW2. The propagation delay time τi to the listening position of the sound to be played is calculated.

  Next, the delay time calculation unit C compares the propagation delay time τi (ie, τ1) related to the high frequency reproduction dedicated speaker TW1 with the propagation delay time τi (ie, τ2) related to the high frequency reproduction dedicated speaker TW2, and propagates. When the delay time τ1 is longer than the propagation delay time τ2, the delay time amount DLY1 for the source signal Sin1 is set to 0, and the delay time amount DLY2 for the source signal Sin2 is set to the propagation delay time τ1 and the propagation delay time. The delay time amounts DLY1 and DLY2 of the delay unit A are set so as to be equal to the difference time (τ1−τ2) from τ2.

  As a result of comparing the propagation delay times τ1 and τ2, when the propagation delay time τ1 is shorter than the propagation delay time τ2, the delay time amount DLY1 for the source signal Sin1 is set to the propagation delay time τ2 and the propagation delay. The delay time amounts DLY1 and DLY2 of the delay unit A are set so that the delay time amount DLY2 with respect to the source signal Sin2 is equal to 0 and the difference time (τ2−τ1) with respect to the time τ1.

  Thus, when the delay time calculation unit C sets the delay time amounts DLY1 and DLY2 of the delay unit A, the high-frequency dedicated signal output delay time adjustment device 1 includes the measurement signal generation unit B, the delay time calculation unit C, and the switching unit. When the delay time setting process by SW is completed, the selector switches SW1 and SW2 in the switching unit SW are switched to the delay unit A side, and the source signals Sin1 and Sin2 supplied from the signal source E are changed to the respective delay time amounts of the delay unit A. The signals are delayed by DLY1 and DLY2 and supplied to the high-frequency reproduction dedicated speakers TW1 and TW2 via the switching unit SW.

  As described above, according to the high-frequency dedicated signal output delay time adjusting apparatus 1 of the present embodiment, the delay time amounts DLY1, DLY2 of the delay unit A can be set according to the human auditory characteristics, and listening The sound image of the high frequency sound can be localized without giving a sense of incongruity to the listener located at the position.

  That is, humans have an auditory characteristic of capturing the moment when a certain loud sound is heard and feeling the direction of the sound (that is, obtaining a sound image localization feeling). From this, when the sound propagation delay time is obtained from the second generation time tfw that is temporally ahead of the first generation time tc described above, the propagation delay time is obtained in accordance with the human auditory characteristics. Further, by calculating and setting each delay time amount DLY1, DLY2 of the delay unit A based on this propagation delay time, it is possible to localize the sound image of the high frequency sound without giving the listener a sense of incongruity It is.

  Further, when setting the delay time amounts DLY1 and DLY2 of the delay unit A, the high-frequency reproduction dedicated speakers TW1 and TW2 are driven by the measurement signal St having the predetermined waveform described above. Even in an environment where the ambient noise is large, the detection signal Sm can be measured by the microphone D without being buried in the ambient noise. For this reason, the propagation delay time can be detected with high accuracy according to the human auditory characteristics, and by setting the delay time amounts DLY1, DLY2 of the delay unit A based on the detected propagation delay time, It is possible to localize a high-frequency sound image without giving a sense of incongruity to the listener.

  In the embodiment described above, the first generation time tc and the second generation time tfw are detected by detecting the peak value of the detection signal Sm obtained from the microphone D. The first generation time tc and the second generation time tfw may be detected by means other than detection.

  For example, the delay time calculation unit C performs a cross-correlation calculation between the detection signal Sm and a reference signal having a predetermined waveform, and the time when the correlation value becomes the maximum is the first generation time tc, and the time when the correlation value next increases. The second generation time tfw may be set.

  As a modification of the cross-correlation calculation, the delay time calculation unit C is provided with an adaptive filter having a filter characteristic corresponding to the inverse function of the transfer function between the high-frequency reproduction dedicated speakers TW1 and TW2 and the listening position. The time when the detection signal Sm is input to the adaptive filter as time passes, the error between the output of the adaptive filter and the measurement signal St is obtained, and the tap coefficient of the adaptive filter is variably adjusted so that the error becomes zero May be the first occurrence time tc. Further, after obtaining the first occurrence time tc, the second occurrence time tfw may be detected by detecting the peak value described above.

  Further, in the high frequency signal output delay time adjusting device 1 of the present embodiment, for convenience of explanation, the high frequency sound emitted from the two high frequency reproduction dedicated speakers TW1 and TW2 is generated without giving a sense of incongruity to the listener. The configuration and operation in the case of localization have been described, but it can also be applied to the case where the high-frequency sound emitted from two or more high-frequency playback dedicated speakers is localized without causing the listener to feel uncomfortable. It is.

  That is, when two or more high-frequency reproduction dedicated speakers are provided, the measurement signal St is supplied to each high-frequency reproduction dedicated speaker, so that the same as in the above-described high-frequency reproduction dedicated speakers TW1 and TW2. And the propagation delay time τi until the sound emitted from each high-frequency reproduction dedicated speaker reaches the listening position is calculated. Then, based on the propagation delay time that is the longest time, the difference time between the remaining propagation delay time and the longest propagation delay time is calculated, respectively, and the longest propagation delay time and each difference time are calculated. By using the delay time amount of the delay unit A, the sound image can be localized without giving a sense of incongruity to the listener even when two or more high-frequency reproduction dedicated speakers are provided.

  Next, more specific examples according to the embodiment shown in FIG. 1 will be described with reference to FIGS.

  FIG. 2 is a block diagram showing the configuration of the high-frequency dedicated signal output delay time adjusting apparatus of the present embodiment, and the same or corresponding parts as those in FIG. FIG. 3 is a flowchart for explaining the operation of the high-frequency dedicated signal output delay time adjusting device.

  In FIG. 2, the high-frequency dedicated signal output delay time adjusting apparatus 1 of this embodiment includes delay circuits A1, A2, a measurement signal generating circuit B, a delay time arithmetic circuit Ca, a buffer memory Cb, and an A / D converter Cc. , Changeover switches SW1, SW2, D / A converters DA1, DA2, preamplifier circuits VG1, VG2 capable of adjusting gain, amplifier circuits AM1, AM2 for power amplification, and microphone D provided at the listening position And an amplifier circuit AMP that amplifies the output of the microphone D by voltage. Although not shown, a control circuit having a microprocessor (MPU) for centrally controlling the operation of the high-frequency dedicated signal output delay time adjusting apparatus 1 is provided.

  FIG. 2 shows, as an example, a case where a tweeter is driven as the high-frequency reproduction dedicated speakers TW1 and TW2 provided in the speaker units SPU1 and SPU2 constituting the multiway speaker system.

  The delay circuits A1 and A2 correspond to the delay unit A shown in FIG. 1A, and delay the high-frequency source signals Sin1 and Sin2 made of a digital data string supplied from the signal source E by a predetermined time. The delayed signals are output as high-frequency driving signals S1 and S2 to be supplied to the high-frequency reproduction dedicated speakers TW1 and TW2.

  The measurement signal generation circuit B generates a measurement signal St having a single waveform corresponding to one cycle τ of a sine wave having a frequency of 11 kHz similar to that shown in FIG. Note that the measurement signal generating circuit B of this embodiment generates a measurement signal St composed of a digital data string.

  The changeover switches SW1 and SW2 are formed of analog switch elements or digital switch elements, and when setting the delay time amounts DLY1 and DLY2 of the delay circuits A1 and A2, the delay circuits A1 and A2 and the D / A converters DA1 and DA2 are set. The measurement signal St output from the measurement signal generation circuit B is converted to the D / A converter DA1 by cutting the connection between the measurement signal generation circuit B and the D / A converters DA1 and DA2. , Supplied to the DA2 side.

  The changeover switches SW1 and SW2 are connected to the delay circuits A1 and A2 and the D / A converter when driving the high-frequency reproduction dedicated speakers TW1 and TW2 based on the source signals Sin1 and Sin2 output from the signal source E. The DA1 and DA2 are connected to each other, and the measurement signal generating circuit B and the D / A converters DA1 and DA2 are disconnected.

  Next, the delay time calculation circuit Ca, the buffer memory Cb, and the A / D converter Cc constitute the delay time calculation unit C shown in FIG. 1A, and the A / D converter Cc includes the microphone D. The detection signal Sm output from the signal amplifier AMP and supplied via the voltage amplifier circuit AMP is input, and the detection signal Sm is A / D converted in accordance with a predetermined sampling frequency, so that the digital data can be obtained without missing the information of the detection signal Sm. Detection data Dm composed of columns is generated and supplied to the buffer memory Cb.

  The buffer memory Cb is formed of a semiconductor memory (RAM) or the like, and stores detection data Dm supplied from the A / D converter Cc in order of time passage.

  The delay time arithmetic circuit Ca is formed by a digital signal processor (DSP) that operates under the control of a microprocessor (MPU) provided in the control circuit described above. Although details will be described later, delay circuits A1, A2 are performed by performing the same processing as the delay time calculation unit C shown in FIG. 1A based on the detection data Dm stored in the buffer memory Cb. The delay time amounts DLY1, DLY2 to be set are calculated.

  The D / A converters DA1 and DA2 convert the digital data string signals supplied from the delay circuits A1 and A2 or the measurement signal generation circuit B side via the change-over switches SW1 and SW2 into analog to analog signals, and are preamplifier circuits. Supply to VG1 and VG2.

  The preamplifier circuits VG1 and VG2 are formed by amplifiers that amplify the analog signals supplied from the D / A converters DA1 and DA2, and the dynamic range is adjusted under the control of the above-described microprocessor (MPU). It has become so.

  The amplifier circuits AM1 and AM2 amplify the signals supplied from the preamplifier circuits VG1 and VG2 and supply the amplified signals to the high-frequency reproduction dedicated speakers TW1 and TW2.

  The microphone D is provided at the listening position, and collects the measurement sound emitted from the high-frequency reproduction dedicated speakers TW1 and TW2 when setting the delay time amounts DLY1 and DLY2 of the delay circuits A1 and A2. Each detection signal Sm is output via AMP.

  Next, the operation of the high-frequency dedicated signal output delay time adjusting apparatus 1 having such a configuration, particularly, the operation when setting the delay time amounts DLY1, DLY2 of the delay circuits A1, A2 will be described with reference to FIG. .

  In FIG. 3, when the operation for setting the delay time amounts DLY1 and DLY2 is started under the control of a microprocessor (MPU) (not shown), first, in step ST1, the changeover switches SW1 and SW2 are used as measurement signals. Switching to the generation circuit B side, the measurement signal generation circuit B outputs the measurement signal St. As a result, sound based on the measurement signal St is emitted from the high-frequency reproduction dedicated speakers TW1 and TW2, and when the microphone D picks up the sound, the detection signal Sm is output. Then, the microprocessor (MPU) checks the value of the detection data Dm output from the A / D converter Cc and adjusts the gain so that the dynamics of the preamplifier circuits VG1 and VG2 which are variable amplifiers are sufficiently large. Do.

  Next, in step ST2, the changeover switch SW1 is switched to supply the measurement signal St to the high frequency reproduction dedicated speaker TW1 as the first object to be measured, and the measurement signal generation circuit B outputs the measurement signal St. The At this time, the speaker outputs other than the measurement target are muted. Then, the A / D converter Cc A / D converts the detection signal Sm obtained when the microphone D picks up the measurement sound emitted from the high-frequency reproduction dedicated speaker TW1 to the buffer memory Cb. Remember me.

  Next, in step ST3, it is determined whether the microprocessor (MPU) has performed the measurement related to the high frequency reproduction dedicated speaker TW1 a predetermined number of times N (eight times in this embodiment). If not, the processing from step ST2 is performed. repeat. And when the measurement of the predetermined number N is completed, it will transfer to step ST4.

  In step ST4, the delay time calculation circuit Ca performs an average calculation on the N detection data Dm stored in the buffer memory Cb so as not to cause a time lag, thereby detecting the detection data as the calculation result. Dmav is generated and stored in the buffer memory Cb.

  Next, in step ST5, a so-called peak value is detected for the maximum value (maximum amplitude) Pmx of the detection data Dmav, and the generation time (first generation time) tc of the maximum amplitude Pmx is detected.

  That is, similarly to the example illustrated in FIG. 1C, the delay time calculation circuit Ca has the first time when the measurement signal generation circuit B generates the measurement signal St (that is, the time 0). Occurrence time tc is detected.

  In this embodiment, instead of detecting the first occurrence time tc as the actual time, the delay time calculation circuit Ca does not detect the address of the buffer memory Cb in which data of the maximum amplitude Pmx is stored (hereinafter “ADRc”). ) Is detected.

  Next, in step ST6, the delay time calculation circuit Ca calculates a level value Lth that is several tens of percent (20 to 30%) less than the maximum amplitude Pmx detected in the peak value, and the level value Lth and the maximum amplitude are calculated. The next maximum amplitude Pfw occurring within the level range Wth between Pmx and ahead of the first generation time tc is detected, and the generation time (second time) of the maximum amplitude Pfw is detected. Occurrence time) tfw is detected.

  In other words, the delay time arithmetic circuit Ca is the detection data Dmav stored at an address ahead of the address ADRc of the buffer memory Cb corresponding to the first generation time tc, and includes the level value Lth and the maximum amplitude Pmx. Detection data having the maximum amplitude Pfw within the range Wth is detected, and the address ADRfw in which the detection data is stored is detected as the second generation time tfw.

  Next, in step ST7, the delay time calculation circuit Ca confirms by itself whether or not the address ADRfw corresponding to the second generation time tfw has been detected as a result of performing the process of step ST6. If it is determined that it has been completed, the process proceeds to step ST8, and if it is determined that it has not been detected, the process proceeds to step ST9.

  Next, in step ST8, the delay time calculation circuit Ca calculates an address difference between the address ADRfw and the address where the head data of the detection data Dmav is stored, and further converts the address difference into A / D conversion. By multiplying the reciprocal of the sampling frequency of the device Cc (ie, the sampling period), the measurement signal St is supplied from the measurement signal generator B to the high frequency reproduction dedicated speaker TW1 (ie, at time 0). 2 is calculated as the actual propagation delay time τi (symbol i is the identification number of the high-frequency reproduction speaker).

  On the other hand, when it is determined in step ST7 that the address ADRfw corresponding to the second occurrence time tfw could not be detected and the process proceeds to step ST9, the delay time arithmetic circuit Ca determines the address ADRc and the detected data. By calculating the address difference from the address where the head data of Dmav is stored, and further multiplying the address difference by the inverse of the sampling frequency of the A / D converter Cc (ie, the sampling period) The period from the time when the measurement signal St is supplied from the signal generator B to the high frequency reproduction dedicated speaker TW1 (that is, the time 0) to the first generation time tc is the actual propagation delay time τi (sign i is calculated as the identification number of the high-frequency reproduction dedicated speaker).

  In this way, the delay time arithmetic circuit Ca detects whether or not the address ADRfw corresponding to the second generation period tfw exists ahead of the address ADRc corresponding to the first generation time tc in step ST7. If the address ADRfw is detected and the propagation delay time τi is calculated by the process of step ST8, the process proceeds to step ST10. If the address ADRfw cannot be detected, the propagation delay time τi is calculated by the process of step ST9, and then the process proceeds to step ST10.

  In step ST10, it is determined whether the above-described microprocessor (MPU) has finished calculating the propagation delay time τi for all the high-frequency reproduction dedicated speakers. If not yet, the remaining high-frequency reproduction dedicated speakers are determined from step ST2. When the above process is repeated and the calculation of the propagation delay time τi for all high-frequency playback speakers is completed, the process proceeds to step ST11.

  In step ST11, the delay time calculation circuit Ca compares the propagation delay times τi for the high-frequency reproduction dedicated speakers, and detects the propagation delay time that is the longest. Then, based on the propagation delay time that is the longest time, the difference time between the remaining propagation delay time and the longest propagation delay time is calculated, and the longest propagation delay time and the difference time Are set as the delay time amounts DLY1, DLY2 of the delay circuits A1, A2.

  For example, when the propagation delay time τ1 related to the high frequency reproduction dedicated speaker TW1 is longer than the propagation delay time τ2 related to the high frequency reproduction dedicated speaker TW2, the delay time amount DLY1 corresponding to the source signal Sin1 is set to 0, The delay time amounts DLY1, DLY2 of the delay circuits A1, A2 are set so that the delay time amount DLY2 for the signal Sin2 is equal to the difference time (τ1-τ2) between the propagation delay time τ1 and the propagation delay time τ2. As a result of comparing the propagation delay times τ1 and τ2, when the propagation delay time τ1 is shorter than the propagation delay time τ2, the delay time amount DLY1 for the source signal Sin1 is set to the propagation delay time τ2 and the propagation delay. The delay time amounts DLY1, DLY2 of the respective delay circuits A1, A2 are set so that the delay time amount DLY2 with respect to the source signal Sin2 is equal to the difference time (τ2-τ1) with respect to the time τ1.

  When the processing in step ST11 is completed, the changeover switches SW1 and SW2 are switched to the delay circuits A1 and A2 side, the source signals Sin1 and Sin2 supplied from the signal source E are delayed by the delay circuits A1 and A2, and the drive signal S1 , S2 are supplied to high-frequency reproduction dedicated speakers TW1, TW2.

  As described above, according to the high-frequency dedicated signal output delay time adjusting apparatus 1 of this embodiment, each delay of the delay circuits A1 and A2 is matched to the human auditory characteristics as in the embodiment shown in FIG. The amount of time DLY1, DLY2 can be set, and the sound image of the high frequency sound can be localized without giving a sense of incongruity to the listener.

  In the high-frequency dedicated signal output delay time adjusting apparatus 1 according to the present embodiment, for convenience of explanation, a high-frequency sound emitted from the two high-frequency reproduction dedicated speakers TW1 and TW2 is generated without giving a sense of incongruity to the listener. The configuration and operation in the case of localization have been described, but it can also be applied to the case where the high-frequency sound emitted from two or more high-frequency playback dedicated speakers is localized without causing the listener to feel uncomfortable. It is.

  In the above description of the embodiments and examples, the case where the propagation delay time of the sound reaching the listening position is adjusted for a plurality of high-frequency reproduction speakers such as tweeters has been described. The present embodiment and examples can also be applied when adjusting the propagation delay time of sound that reaches a listening position between speakers that reproduce sound.

  In the above description of the embodiment and examples, the case where the delay unit A, the measurement signal generation unit B, and the delay time calculation unit C are formed by so-called hardware has been described. It may be configured to operate according to a computer program. That is, the delay unit A, the measurement signal generation unit B, and the delay time calculation unit C are formed by a microprocessor (MPU) or a digital signal processor (DSP), and the delay unit A, the measurement signal generation unit B, and The microprocessor or the digital signal processor may be operated in accordance with a computer program that performs the same function as the delay time calculation unit C.

  In addition, when the high-frequency dedicated signal output delay time adjusting device 1 described in the above embodiments and examples is installed in an in-vehicle audio device or a home use audio device, an information reproducing device provided in the audio device Thus, the information recording / reproducing medium in which the above-described computer program is recorded may be informed and installed, and the microprocessor or the digital signal processor may be operated in accordance with the installed computer program.

  Further, as an information recording / reproducing medium (storage medium) for recording a computer program that exhibits the same functions as the delay unit A, the measurement signal generator B, and the delay time calculator C described above, CD (Compact Disc), DVD ( Digital Versatile Disc), semiconductor memory, or the like may be used.

It is a figure for demonstrating the structure and operation | movement of the high frequency signal output delay time adjustment apparatus which concern on embodiment of this invention. FIG. 2 is a block diagram showing the configuration of a more specific example of the high-frequency dedicated signal output delay time adjusting device shown in FIG. 1. 3 is a flowchart for explaining the operation of the high-frequency dedicated output delay time adjusting device shown in FIG. 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... High frequency exclusive signal output delay time adjustment apparatus A ... Delay part B ... Measurement signal generation part C ... Delay time calculating part D ... Microphone TW1, TW2 ... High frequency reproduction exclusive speaker

Claims (7)

A high-frequency dedicated signal output delay time adjusting device that localizes a sound image at a listening position of sound emitted from a plurality of high-frequency reproduction dedicated speakers,
Delay means for delaying a high-frequency dedicated signal supplied from a signal source based on a delay time amount, and supplying the delayed signal to the high-frequency reproduction dedicated speaker;
Measurement signal generating means for supplying a measurement signal to the high-frequency reproduction dedicated speaker;
Sound collecting means for collecting measurement sound emitted from the high-frequency reproduction dedicated speaker based on the measurement signal and outputting a detection signal;
Delay time calculating means for calculating and setting the delay time amount of the delay means based on the detection signal output from the sound collecting means;
The delay time calculation means detects a first generation time and a maximum amplitude value at which the amplitude of the detection signal becomes maximum, and at the time when the measurement signal is supplied to the high-frequency reproduction speaker. A second generation time in which the amplitude of the detection signal becomes the next maximum within the range of the generation time and within the range of the maximum amplitude value and a level value set lower than the maximum amplitude value by a predetermined level. And detecting the delay time amount based on a propagation delay time from the time when the measurement signal is supplied to the high frequency reproduction dedicated speaker to the second generation time. Output delay time adjustment device.   The range between the maximum amplitude value and a level value set lower than the maximum amplitude value by a predetermined level is set with respect to the maximum amplitude value at a ratio according to auditory characteristics. The high-frequency dedicated signal output delay time adjustment device described.   If the second generation time is not detected, the delay time calculation means calculates the propagation delay time from the time when the measurement signal is supplied to the high frequency reproduction speaker to the first generation time. The high frequency dedicated signal output delay time adjusting device according to claim 1, wherein the delay time amount is calculated as follows.   4. The measurement signal according to claim 1, wherein the measurement signal is a signal having a waveform in which a gain of a high frequency component is higher than a low frequency component on a frequency axis. The high-frequency dedicated signal output delay time adjustment device described. A high frequency signal output delay time adjustment method for localizing a sound image at a listening position of sound emitted from a plurality of high frequency reproduction dedicated speakers,
A delay step of delaying a high-frequency dedicated signal supplied from a signal source based on a delay time amount and supplying the delayed signal to the high-frequency reproduction dedicated speaker;
A measurement signal generating step of supplying a measurement signal to the high-frequency reproduction dedicated speaker;
A sound collecting step for collecting measurement sound emitted from the high-frequency reproduction speaker based on the measurement signal and outputting a detection signal;
A delay time calculating step of calculating and setting the amount of delay time based on the detection signal,
The delay time calculating step detects a first occurrence time and a maximum amplitude value at which the amplitude of the detection signal is maximum, and at the time when the measurement signal is supplied to the high frequency reproduction dedicated speaker and the first time A second generation time in which the amplitude of the detection signal becomes the next maximum within the range of the generation time and within the range of the maximum amplitude value and a level value set lower than the maximum amplitude value by a predetermined level. The delay time amount is calculated based on a propagation delay time from when the measurement signal is supplied to the high-frequency reproduction dedicated speaker to the first and second generation times. Dedicated signal output delay time adjustment method. A program in a high-frequency dedicated signal output delay time adjustment device for processing sound image localization processing at a listening position of sound emitted from a plurality of high-frequency reproduction dedicated speakers by a computer,
A delay step of delaying a high-frequency dedicated signal supplied from a signal source based on a delay time amount and supplying the delayed signal to the high-frequency reproduction dedicated speaker;
A measurement signal generating step for supplying a measurement signal to the high-frequency reproduction dedicated speaker;
A sound collecting step for collecting measurement sound emitted from the high-frequency reproduction speaker based on the measurement signal and outputting a detection signal;
A delay time calculating step for calculating and setting the amount of delay time based on the detection signal,
The delay time calculating step detects the first occurrence time and the maximum amplitude value at which the amplitude of the detection signal is maximum, and at the time when the measurement signal is supplied to the high frequency reproduction dedicated speaker and the first time A second generation time in which the amplitude of the detection signal becomes the next maximum within the range of the generation time and within the range of the maximum amplitude value and a level value set lower than the maximum amplitude value by a predetermined level. Detecting and calculating the amount of delay time based on propagation delay times from the time when the measurement signal is supplied to the high-frequency reproduction speaker to the first and second generation times . 7. An information recording / reproducing medium in which the program according to claim 6 is recorded.

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