A Design Method for Thin Sound-absorbing Structures for Low-Frequency Noise Containing Multiple Single-Frequency Components

Abstract

The invention discloses a thin sound absorption structure for low-frequency noises containing multiple single-frequency components and a design method thereof. The structure is that a branch circuit 1formed by serially connecting an inductor L1, a capacitor C1 and a negative resistor -RE1, a branch circuit 2 formed by serially connecting an inductor L2, a capacitor C2 and a negative resistor -RE2, ......, and a branch circuit N formed by serially connecting an inductor LN, a capacitor CN and a negative resistor -REN are connected in parallel, and are serially connected with a negative resistor -RE to form a shunt circuit, and then the shunt circuit is connected in parallel to two ends of a moving-coil loudspeaker unit. The sound absorption structure is designed based on a shunt loudspeaker, wherein each branch resonant loop of the shunt circuit can be designed independently of each other, and for multiple single-frequency components at a low frequency, better absorption can be achieved, and the thickness of the structure only depends on the loudspeaker unit.

Description

[0001] 1. Technical field [0002] The invention proposes a design method for a thin sound-absorbing structure aimed at low-frequency noise containing multiple single-frequency components. [0003] 2. Background technology [0004] Toned noise contains an obvious fundamental frequency and noise accompanied by fundamental frequency and harmonics. It does not belong to broadband noise and is noise containing multiple single-frequency components. [0005] Traditional sound-absorbing treatment mainly uses porous sound-absorbing materials and resonant sound-absorbing structures. Porous sound-absorbing materials are poor at low-frequency sound absorption and often cause environmental pollution. The resonance of the Helmholtz resonator is very sharp, and its sound absorption ability is very strong at the resonance frequency. Once it deviates from this frequency, the sound absorption coefficient will decrease rapidly, so it is suitable for single-frequency sound absorption. Using a c...

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Problems solved by technology

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