JPS63204898A - Acoustic reproducing device - Google Patents

Abstract

PURPOSE:To eliminate a sound offset phenomenon in a low frequency band and to improve the quality of a reproduce sound in the low band by constituting the titled reproducing device of a speaker which reproduces a signal changing a signal from an electric signal geneartor and a speaker that directly reproduces a signal from the generator. CONSTITUTION:By shifting the phases in the low frequency band of rear speakers 3, 4 by a phase circuit 10, the offset phenomenon that conventionally occurred in the low frequency band between speakers 1, 2 and 3, 4 can be prevented. That is, by shifting the phase in the low-frequency-band part (a part loss than 100Hz) of the characteristic 6 of the rear speakers (this does not influence the output sound pressure), the output sound pressure is made higher in the low frequency band of the synthetic characteristic of the rear speakers 3, 4, and thus the quality of sound is improved.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a sound reproduction device.

Conventional technology The in-vehicle sound reproduction system uses multiple speakers in the front seats.

It is often placed in the back seat to improve sound quality and playback ability.

FIG. 5 shows a typical four-speaker sound reproducing device consisting of speakers 1 and 2 for front seats mounted on a front in-panel and speakers 3 and 4 mounted on a rear tray.

Problems to be Solved by the Invention However, due to the unbalance of the acoustic energy radiated from a large number of sound sources within the narrow space of the vehicle interior, there is also the problem that the expected acoustic energy cannot be transmitted to the listener. That is, FIG. 6 shows an example of the transmission characteristics measured by installing an acoustic measuring microphone at approximately the position of the listener's ears in the driver's seat. The transmission characteristics 5 of only the front speakers 1 and 2 and the transmission characteristics 6 of only the rear speakers 3 and 4 are as shown in the same figure. Therefore, the overall transmission characteristic is 7. In the same figure, the transmission dynamics were measured by inputting the same level of signal to each speaker 1 to 4, but
As shown by diagonal lines, it can be seen that the acoustic energy radiated from the speakers 2 and 3 and 4 is not combined in the low range and is reduced. This is particularly true for the front speakers 112, especially in the bass range with long wavelengths. Due to the difference in the distance between the J-A speakers 3 and 4, the difference in the arrival time of acoustic energy to the listener, and the difference in the mounting condition, in the driver's seat, the low range radiated from the front speakers 1°2 and the low range radiated from the rear speakers 3 and 4. This is a phenomenon that occurs due to cancellation due to the fact that the phases of the low frequencies do not match. An object of the present invention is to provide a sound reproduction device that can eliminate these losses of sound energy.

By setting Vcfa near 50)4z in this way, the low frequency phase at the listening point radiated from the front and rear matches, and the low frequency level increases. f using this example. By setting the two-phase circuit order, etc., it is possible to increase or decrease the sound synthesis level in a wide frequency band.

Means for Solving Interlayer Points The present invention provides a sound reproducing device comprising a speaker that reproduces a signal obtained by changing the signal of an electric signal generator, and a speaker that directly reproduces the signal of the generator. It is.

By shifting the phase of the low frequency range of the front speaker or the rear speaker, the cancellation phenomenon in the low frequency range is eliminated and the reproduced sound in the low frequency range is improved.

Example FIG. 1 is a circuit diagram according to an embodiment of the present invention.

In the same figure, 8 is a sound source, 9 is a front amplifier, 1o
1 is a phase circuit that shifts the phase of only the low frequency band, 11 is a rear amplifier, and the same numbers as in FIG. 6 indicate the same parts. In this embodiment, the low frequency phase of the rear speakers 3 and 4 is controlled by the phase circuit 1o.
By shifting the distance between the two speakers, it is possible to prevent the cancellation phenomenon between the speakers 1 and 2 and between the speakers 3 and 4 that conventionally occurred in the low frequency range.

FIG. 2 specifically explains this. In the figure, the low frequency part (100
By shifting the phase of the parts (below H2) (which does not affect the output sound pressure), the synthesis characteristics of front speakers 1 and 2 and rear speakers 3 and 4 are changed, as is clear when compared with the case in Figure 6. It can be seen that the output sound pressure is high in the low range and has been improved.

3e) and 3(b) are circuit diagrams of specific embodiments of the phase circuit 10. In the figure, 13 to 16 are resistors, 17 is a capacitor, and 18 is an OP amplifier.

Figures 4(a) and (b) are similar to Figure 3(a) and (b).
FIG. 2 is a phase characteristic diagram corresponding to FIG. FIG. 4(2L) shows the phase becoming 0 as the frequency increases, and FIG. 4(b) shows the opposite. This adjustment is made by resistor 16.

As described above, according to the present invention, it is possible to eliminate the cancellation phenomenon of the synthesized signal, and it is possible to reproduce faithful sound.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram according to an embodiment of the present invention, Fig. 2 is a transmission characteristic diagram of this embodiment, Fig. 3 is a phase circuit diagram used in this embodiment, Fig. 4 is its characteristic diagram, and Fig. 5 6 is a schematic diagram showing an example of a four-speaker system, and FIG. 6 is a transmission characteristic diagram of the four-speaker system. 1.2...Front speaker, 3,4...
...Rear speaker, 1o...Phase circuit. Name of agent: Patent attorney Toshio Nakao and one other person 1.
2-Scope force 71-Rear seal Figure 2

Claims (2)

[Claims] (1) an electric signal generator that generates an electric signal corresponding to the sound to be reproduced, a phase circuit that changes the phase of the signal of this generator, and a first speaker that directly reproduces the signal of the generator; and a second speaker that reproduces the signal from the phase circuit. (2) The sound reproduction device according to claim 1, wherein the phase circuit is realized by a phase shifter.