Digital coding and modulation airflow speaker

Abstract

The invention relates to a digital coding modulated pneumatic loudspeaker, including air source, control valve group, air collecting throat in tube shape, bimetallic cone and horn connected in series, wherein the air source is connected to air collecting throat in tube shape through m air inlet passages, with airflow ratio among the m air inlet passage fixed, and inlet valve for controlling make-break of the passage equipped in each air passage. The mentioned M is at least 2. The invention has following technical effect: no moving component is included in the vocalizing throat; high power output can be carried out, total area of modulation is big, generated sound level is high; requirement to air quality is low; modulation effect of high linearity can be achieved; no air leakage; high reliability, long life; easy to maintain; high efficiency in gas-acoustic energy conversion. The invention solves problem of low stability of analogue modulation valve in infrasound frequency and low frequency band, and is beneficial for generating infrasound of low frequency.

Description

technical field [0001] The invention belongs to the field of acoustics, in particular, the invention relates to an airflow loudspeaker. Background technique [0002] The airflow speaker is a high-power speaker that can adjust the air flow to produce sound, and utilizes the horn 15 to realize effective sound radiation in the air, including a flute-type sound source that uses a rotary regulating valve to adjust the air flow to generate single-frequency noise, and uses voice (or music) signal to adjust the air flow to produce voice (or music) sound sources and other types, mainly used to achieve high-power sound radiation, usually can generate sound sources of the thousand to ten thousand sound watts level. It is used for long-distance broadcasting, or as a sound source for high-sound-intensity sound field tests (such as high-sound-intensity fatigue tests), or for high-power sound sources required for special applications, and can also be used to drive birds at airports. Airfl...

AI Technical Summary

Problems solved by technology

[0004]The deficiencies of this analog modulating valve airflow speaker include:

[0005]1. In the case of high-power output, such as 10,000-watt-level high-sound intensity speakers, a large amount of airflow is controlled by a modulation valve, and the modulation ring has to withstand High pressure is easy to deform and cause air leakage. At the same time, friction occurs between the modulating ring and the fixed ring, which makes it easy to damage. More importantly, the weight of the modulating ring increases the load on the coil, so the current required by the coil is large, which increases the pressure. When the power is high, the coil is easy to overheat and burn out, which is the key problem of the short life of the modulating valve; in addition, when the high-power sound level is generated, the air flow will load a large force on the modulating valve, which requires high strength of the modulating valve. As a result, a series of problems such as heavy coil weight, high power consumption, and large coil volume are caused.

[0006]2. Due to the wear and tear caused by the mechanical movement of the modulating valve, air leakage occurs, and the distance between the moving ring and the fixed ring is too large, resulting in air-acoustic energy Problems such as low conversion efficiency, nonlinear modulation, large background noise, and difficult maintenance

[0008]4. When the coil drives the modulation ring to move, it is prone to instability in the low-frequency audio frequency band and the infra-audio frequency band, so it is not conducive to the generation of low-frequency and infra-audio frequency sounds

At the same time, due to the heavy weight of the modulation ring, the modulation coil cannot drive the modulation ring to vibrate at high frequencies, which is not conducive to producing high-frequency sounds.

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