A Study on Sound Radiation Characteristics of Slim Speaker System

For ultra-thin TVs, slim speaker enclosures are usually used to reduce the thickness. These slim speaker systems can suffer from acoustic problems such as poor radiated sound performance in a specific frequency range. This paper studies the sound radiation performance improvement of the slim speaker system. First, it experimentally confirms the poor frequency response at the specific frequency of the speaker system. Then, it is investigated why the speaker frequency response is poor at the frequency through the numerical method. It is found that the radiated sound pressure decreases due to the destructive interference caused by the 180-degree phase difference between the incidence wave and the reflected wave at the corresponding frequency. To improve sound radiation performance, three types of noise control methods are suggested: (1) installing a sound-absorbing material, (2) installing a membrane on the reflective surface in the enclosure, and (3) providing a slit at the top of the enclosure. The proposed method is verified through experiments.