CN2256615Y - Household active super low voice box - Google Patents

Abstract

The utility model discloses a household active super low sound box which is composed of a box body, a circuit part, a speaker and two sections of circular pipes of different sizes, wherein, the circular pipes are arranged on a front panel of the box body. The circular pipe of the larger size and the speaker are coaxially arranged and positioned at the right ahead of the speaker. The circuit part is positioned on a back cover of the box body and a partition plate. The circuit comprises a power supply circuit, a low pass filtering circuit, a band pass filtering circuit, a power amplifier circuit and a passive low pass filtering circuit. The super low sound box has the advantages of high sound pressure, small volume and convenient usage. A sound source signal is fed into an input terminal on the panel of the box body, a volume rotary knob is adjusted, and the output of low sound is matched with original sound effect best.

Description

The active ultralow audio amplifier of family expenses

The utility model belongs to a kind of stereo set that occasions such as the less dancing hall in family and space, video arcades are used, and promptly increases the audio amplifier of low frequency and ultralow frequency acoustic pressure.

In the designing and producing of audio amplifier, the acoustic pressure curve of audio amplifier should be as best one can to low frequency end level and smooth extend wideer in the hope of the frequency range that makes the acoustic pressure flat response, thereby obtain true, perfect low frequency audio.But be limited to the characteristics that whole tone frequency audio amplifier will be considered high, medium and low each frequency band audio response comprehensively, its acoustic pressure curve does not often reach level and smooth extension in low-frequency range below 40Hz, thereby making the especially acoustic pressure deficiency of the ultralow frequency range below the 40Hz of low-frequency range, this does not reach desirable effect in audition.

Adopting the 3D system is the better method that solves the low-frequency sound pressure deficiency.In the 3D system, bass, middle pitch and high pitch in reproducing well with two less audio amplifiers of volume, and utilize the characteristics of bass directivity difference, with a mega bass case low frequency signal below the certain frequency is ideally reset in addition, combine with the audio of whole tone frequency audio amplifier, produce grand imposing manner and graceful acoustics.Be used for the ultralow audio amplifier of the less space of family or other 3D system at present, mostly be made of two Helmholtz's resonators, the audio amplifier of this structure exists shortcomings such as electro-acoustic conversion efficiency is low, acoustic pressure is not enough, the casing volume is excessive.

The utility model is a kind of active ultralow audio amplifier of design, makes it reach the raising acoustic pressure, corresponding purpose of dwindling the audio amplifier volume.

The utility model is to be realized by following technical proposal: it comprises casing, circuit part and loud speaker, wherein casing has front panel and back shroud, circuit part comprises power circuit, low-pass filter circuit and power amplifier, this ultralow audio amplifier feature part is two sections different pipes of size to be set be also referred to as gun tube (1,2) the coaxial positive front end that places loud speaker 7 of wherein larger-size one section pipe on the front panel 4 of casing; The pipe that size is less and the part of casing constitute Helmholtz's resonator 9, are connected in series a bandwidth-limited circuit of being made up of operational amplification circuit IC2a, IC2b and peripheral cell thereof with the input of power amplification circuit at the output of low-pass filter circuit; Be connected in series a passive low-pass filter circuit of forming by inductance L 1, L2 and capacitor C 13～C16 thereof with the input of loud speaker at the output of power amplification circuit.

The utility model adopts the woofer front end that one section pipe is set in design and by casing and one section sound system that Helmholtz's resonator that less pipe constituted links up, the advantage of have raising acoustic pressure (acoustic pressure is improved more than the 6dB), dwindling corresponding audio amplifier volume; And the signal of tackling a certain frequency range in circuit design mutually carries out a certain amount of lifting, so that whole system reaches optimum Match; Extremely easy to use, only need line input with source of sound (the audio frequency output of CD player, colour TV etc.) this case of signal feed-in, regulate volume knob and make the volume of mega bass cooperate best getting final product with the whole tone yupin effect of former sound system.

Description of drawings of the present utility model:

Fig. 1 is the utility model monnolithic case structural representation.

Fig. 2 is the utility model overall structure profile.

Fig. 3 is the circuit part theory diagram.

Fig. 4 is the power circuit principle figure of circuit part.

Fig. 5 is the filtering and the power amplifier schematic diagram of circuit part.

1～5 pair of overall structure of the present utility model and operation principle thereof are done one and are described in detail in conjunction with the accompanying drawings:

As shown in Figure 1, 2, the pipe 1,2 of two sections different sizes is also referred to as the main armament pipe and secondary gun tube 1,2 installs on the front panel 4 of casing 5, the positive front end of the mouth of pipe of main armament pipe 1 and loud speaker 7 matches, and by reinforcement 3 reinforcings, weld together by a connection piece between major and minor gun tube, circuit part 8 devices are on the back shroud 6 and dividing plate of casing, and secondary gun tube 2 and part casing constitute Helmholtz's resonator 9.Casing is provided with guidance panel 10, and L, R line input, volume knob and mains switch are set thereon.Main purpose of the present utility model is to improve low-frequency sound pressure, so be to adopt the method that strengthens the air movement amount in design, one section pipe (main armament pipe) therefore is set in order to strengthen the air movement amount in the place ahead of loud speaker, can make acoustic pressure improve 6dB like this.The desirable f of the resonance frequency of Helmholtz's resonator in actual applications _oIf=20～30Hz is f _oDuring=25Hz, then the making of whole box body is desirable is of a size of: main armament pipe 160mm * 580mm, secondary gun tube 50mm * 430mm, box sizes 390 * 280 * 280mm ³, tank material can be the 19mm medium-density plate, the desirable PVC material of major and minor gun tube and front panel, and back shroud is the thick copper coin of 1mm, by the heating panel of its double as power amplification.Circuit part is separated fully by dividing plate and last of the twelve Earthly Branches chamber air.

By shown in Figure 3, the circuit part of this ultralow audio amplifier mainly comprises two large divisions's circuit, power circuit and filtering and power amplifier, power circuit provides working power for filter circuits at different levels and power amplifier specially, referring to Fig. 4, power circuit is made of four groups of common bridge rectifiers and capacitor filter thereupon, by its output V1, V2, four groups of voltages of V3, V4, V1, V2 provide power amplifier voltage, V3, V4 provide filter circuit voltage.By Fig. 3, the formation of filtering shown in 5 and power amplifier, by the active low pass filtered circuit of second order, the active bandwidth-limited circuit of second order, power amplification circuit and passive filter circuit are formed, just by shown in Figure 5, the left and right sound track signals of source of sound is the IC1a in double operational IC1 respectively, second order active low-pass filter circuit (the cut-off frequency 150～250Hz) that IC1b and peripheral element thereof constitute, filtering is after resistance R 7, R8 mixes, IC2a in four high guaily unit IC2 again, promote integrated amplifier IC circuit 3 by IC2c behind the second order adjustable band pass filter circuit filtering that IC2b and peripheral element thereof are formed and carry out power amplification, the signal after the amplification is via inductance L 1, L2, the passive filter filtering pusher dynamic load R2 that capacitor C 13～C16 constitutes is the loud speaker sounding.So in circuit, a certain amount of lifting can be arranged, to adapt to the architectural characteristic of novel casing to the ultra-low frequency signal between 20～30Hz owing to be provided with adjustable bandwidth-limited circuit; Be provided with passive low-pass filter circuit in addition, make bass purer.

Novel characteristics according to this bass box, when the loud speaker sounding, the back side excitation of the diaphragm of loudspeaker produces resonance by Helmholtz's resonator that casing air path part and secondary gun tube constitute, Helmholtz's resonator is with the sound wave paraphase, air in the secondary gun tube is done the significantly vibration of similar single pendulum, more substantial air adduction mutually in the positive main armament pipe that promotes of this vibration and the diaphragm of loudspeaker sends the low-frequency sound wave of high sound pressure level.

Claims (1)

1. the active ultralow audio amplifier of family expenses comprises casing, circuit part and loud speaker, and wherein casing has front panel and back shroud, and circuit part has power circuit, low-pass filter circuit and power amplifier, it is characterized in that:

A., two sections pipes (1,2) that size is different are set on the front panel (4) of casing, and wherein larger-size one section pipe (1) places the coaxial positive front end of loud speaker (7), and the pipe that size is less and the part of casing constitute Helmholtz's resonator (9).

B. be connected in series a bandwidth-limited circuit of forming by operational amplification circuit IC2a, IC2b and peripheral cell thereof with the power amplifier input at the output of low-pass filter circuit.

C. be connected in series a passive low-pass filter circuit of forming by inductance L 1, L2 and capacitor C 13 thereof, C14, C15, C16 with the input of loud speaker at the output of power amplifier.

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