SNB Active Noise Control System

Characteristics of SNB
(Active Noise Control System)

・The Active Noise Control System adds a reverse phase wave with the original sound wave.

・Based on sound route characteristic, we can then realize the most suitable frequencies to minimize the noise.

・Control a wide area with a set number of Controlled Sound Speakers with various setting to counteract the original noise. Reduce the low frequency noise in wide area by arranging the Controlled Sound Speakers in a straight line close to the targeted noise.

Reduce noise levels by adding sound!
The Worlds finest performance ANC (Active Noise Control)

The theory behind the ANC (Active Noise Control) system is to add a completely opposite sound wave against the original sound wave. This secondary sound wave will then cancel the original sound.

The ANC can be freely adjusted therefore you are set up for the maximum sound canceling effect. It is possible to reduce a noise levels by 10db, which is far more effective than any previous system.

In Japan (2008), the number of complaints for noise was 16,215 and has been steadily increasing. As a noise source, 34.8% of the complaints were related to factory noise while construction site noise was at 28.7%. In recent years, low frequency noise has also becomes a continuing problem.
Depending on the noise level, this problem has become a public nuisance that has even been taken to trial. For this reason, factories and construction sites have been retrofitting their rooms with anti-noise equipment such as soundproof walls and noise barriers. This may be a temporary fix to lessen the noise but complaints still exist due to the constant noise being produced. Recently, the ANC technology has been implemented in a sound reducing headphone. There was also a system created to make the inside of an automobile quiet. The ANC technology has also been united with the Noise-barrier system and this has helped reduce the amount of outdoor noise in specific places.

The Principle of the ANC (Active Noise Control)

Reduces noise levels by adding artifical sound to completely reverse the phase wave. The ANC will then cancel the sound from its source.

The Basic Setup of the ANC

1．Measure impulse response A from the noise source to the microphone and the controlled area behind the barrier.

2．Measure impulse response B from the controlled sound speaker to control a certain area and uncover the reverse phase wave.

3．Execute real-time convolution integration in the control unit and maintain the targeted area.

Basic Composition of the ANC

① Sensor microphone

② Control unit + amplifier (indoor)

③ Control sound speaker

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