JPS63217899A - Vehicle acoustic reproducing device - Google Patents

Abstract

PURPOSE:To obtain a natural HiFi sound by stabilizing the static position of a sound and generating the expansion of a sound, by setting a sound pressure level difference of right and left loudspeaker groups to average + or -3dB in a driver's seat or an assistant's seat, by an acoustic lens, etc., and connecting a delaying circuit to the remaining loudspeakers. CONSTITUTION:In loudspeakers SL, SR of each channel, outside loudspeakers SL1, SR1 are provided with an acoustic lens L, the delaying circuit of 4ms-100ms is integrated, and this device is constituted so that the sound pressure level difference of right and left loudspeaker systems goes to + or -3dB in the driver's seat and the assitant's seat. In a vehicle, the distance of the right and left loudspeaker systems is about 0.5m-1m, and the arrival time of a sound from a sound source to a listener is about 0.15ms-0.3ms (sound speed 340m/s), therefore, it is necessary that the delay time is larger enough than this time. Also, said time is set to >=4ms so that the difference of sound pressure of the loudspeaker system to which a delay is applied, and the sound pressure of the loudspeaker system to which a delay is not applied becomes >=10dB, and also, <=100ms by which the sound is separated completely as an echoe is set to the upper limit.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a vehicle-mounted sound reproduction Vt device, and more particularly to a vehicle-mounted sound reproduction device for a Hi-Fi sound field.

[Conventional technology and problems]

In conventionally known in-vehicle sound reproducing devices, the speaker system is attached to the dash board, rear parcel tray, etc., and the left and right speaker systems are placed near both ends of the vehicle to separate them. However, in the case of an in-vehicle sound field, the listening position is either the driver's seat, the passenger's seat, or even the left or right side of the back seat, and the reproduced sound is placed on the center line of both the left and right speaker systems, like a home stereo system. For example, when listening to reproduced sound through a speaker system attached to the dash board, 1. The left and right speaker systems are too close. 2. A sound pressure phase difference occurs between the left and right speaker systems. Due to this, the localization of sound becomes unnatural. This also applies when a speaker system is attached to the rear parcel tray, and the localization becomes unnatural, especially in the rear seats. Speaker systems are also installed on vehicle doors and kickboards, but the sound pressure of the left and right speaker systems is masked by the passenger, and the sound axes of the left and right speaker systems face each other. The left and right sounds cancel each other out, requiring speakers with good directional characteristics. In short, the following problems remain in the conventional sound reproduction device '4A. (2) There is not enough space between the left and right speaker systems,
Both are too close. Φ) A sound pressure phase difference occurs between the left and right speaker systems. Therefore, sound localization is unnatural.

[Means for Solving the Problems] Therefore, this invention takes into consideration the special characteristics of an in-vehicle sound reproduction device, improves the directional characteristics, and incorporates a delay circuit of 4+as to 100IIIS into one speaker system. The system is characterized in that the sound pressure level difference between the left and right speaker systems is ±3 dB between the driver's seat and the passenger's seat. In vehicles, the distance between the left and right speaker systems is 0.511~
The travel time of sound from the sound source to the listener is approximately 0.15s+s ~ 0.3+es (sound speed 340m/
s ), and the delay time needs to be 4 minutes larger than this time, so that the sound pressure difference between the speaker system with delay and the speaker system without delay is 1
The upper limit is set to 4 w+sg so that it is 0d3 or more, and the upper limit is set to 100 m5 or less, which is the level at which the sound is completely separated as an echo. [Example] Next, an example of the present invention will be described with reference to the attached drawings. First, in FIG. 1 etc., the symbol 1o indicates a vehicle,
11 indicates the dash board, and in Fig. 1,
Speakers SL and SR for LCH and RCH are arranged on the left and right sides of the dash board 11, and speakers S for each channel are arranged.
L, SFL is the second side group, and the speaker SL of the - group
, the sound axis of the outer SH is tilted toward the center of the passenger compartment. Further, in this figure, reference numeral 12 indicates a driver's seat, reference numeral 13 indicates a passenger seat, 12P indicates a driver, and 13P indicates a fellow passenger. In FIG. 2, among the speakers SL and Sp of each channel, the outer speakers SLt and 5FLt are equipped with acoustic lenses L to improve the directivity characteristics. Instead of this acoustic lens, an equalizer or the like may be used. Figure 3 shows a shielding plate B provided outside the speakers SL, SLs and SRt of each channel to refract the radiated sound, and Figures 4 and 5 show the speakers SLs and SRt of each channel. A delay circuit DL is incorporated in one of the groups SL and 83, and in the above figures, the same parts as in the embodiment of FIG. 1 are given the same reference numerals. Figure 6 shows the time difference and sound pressure difference between the sounds heard by both ears of the listener, Figure 7 shows the output sound pressure characteristics of the right speaker in comparison with the conventional example, and Figure 8 shows the left speaker. It is a diagram showing the output sound pressure characteristics of the speaker in comparison with a conventional example, and it can be seen that the sound pressure is flat in the high range. 15= In the above explanation, the left and right channel speakers were installed on the dash board in front of the driver, etc., but it can also be applied when they are installed on the rear parcel tray, door, kickboard, etc. can.

【Effect of the invention】

As is clear from the above description, according to the in-vehicle sound reproduction device of the present invention, each channel is reproduced by a plurality of speaker systems, and at least one of the speaker system groups of each channel is placed in the center of the sound field. In addition, an acoustic lens, a horn, an equalizer, and a shielding plate are installed so that the sound pressure level difference between the left and right speaker groups is on average ±3 CIBL/ in the driver's seat or passenger seat, and a delay circuit is installed in the remaining speakers. After connecting and configuring it, you will get the following effects. 1. The sound pressure phase difference between the left and right speaker systems is improved, and localization is stabilized. 2. Appropriate delay creates a broader sound. 3. The localization of the sound becomes accurate and a natural tu F+ sound can be obtained. 4. There is no change in sound quality depending on the seat.

[Brief explanation of the drawing]

Figure 1 shows one of the left and right channel speaker systems.
Figure 2 is an explanatory diagram of a vehicle plane with the sound axis tilted toward the center of the sound field, Figure 2 is an explanatory diagram of a vehicle plane using an acoustic lens, and Figure 3 is an illustration of a vehicle plane using the same shielding plate. 4 is an explanatory diagram of the vehicle plane using a delay circuit, FIG. 5 is an explanatory diagram of the speaker drive circuit for each channel, and FIG. 6 is an explanatory diagram of the relationship between the time difference between both ears and sound pressure. 7 and 8 are output sound pressure characteristic diagrams showing the output sound pressure characteristics of the left and right speaker systems in comparison with a conventional device. 10... Vehicle, 11... Datsushi board, 12...
・Driver's seat, 13...Passenger seat, SL, SR...Speaker group for left and right channels. Figure 1 Figure 3 Figure 4

Claims (1)

[Claims] (1) In an in-vehicle sound reproduction device configured by installing multiple speakers for each channel on the rear parcel tray, dashboard, sun visor, etc., the sound axis of at least one speaker system in each channel group is the center of the sound field. Tilt the left and right channel speakers toward the driver's seat and front passenger's seat by using an acoustic lens, horn, equalizer, or shielding board to keep the sound pressure difference between the left and right channel speakers at ±3 dB, and set the sound pressure difference between the left and right channel speakers at the driver's and passenger's seats to within ±3 dB. 100ms
An in-vehicle sound reproducing device characterized in that it is configured by connecting delay circuits.