(Boshi Audio-Visual Systems (Shanghai) Co., Ltd.)

(Harman (China) Investment Co., Ltd.)

(Zhuhai Huiwei Technology Co., Ltd.)

(Yamaha Musical Instruments Audio (China) Investment Co., Ltd.)

(Philips (China) Investment Co., Ltd.)

(Shenzhen Edifier Technology Co., Ltd.)

(Shanshui Electronics (China) Co., Ltd.)

The speaker box is also called a speaker box. It puts speakers working in different frequency bands into a specially designed box and divides them through a frequency divider. The output signal of the power amplifier is divided into high-frequency, medium-frequency, and low-frequency signals and then sent to the corresponding speakers for playback. There are many types of speakers with different functional scopes and different classification methods. The commonly used classification methods are as follows:

1. According to use: floor-standing speakers, active speakers, surround speakers, bookshelf speakers , ** speakers. According to the working frequency: subwoofer speakers, multi-way speakers, 2-way speakers, 3-way speakers. According to the internal structure: sealed speakers, inverted speakers, empty paper cone speakers, symmetrical drive speakers, labyrinth speakers, and dumbbell speakers. Commonly used speakers are introduced below:

(1) Sealed speaker structure? The structure is shown in Figure 155(a). It is composed of a box, a speaker, and sound-absorbing materials. The back of the speaker is sealed, and there is a speaker opening in the front. The speaker is installed in a completely sealed box. The sound of the box is basically sealed, separating the sound waves in front and behind the speaker.

Features: It has good low-frequency response and reproduces deep bass, and because the speaker is fully enclosed (except for the speaker), it prevents the phenomenon of acoustic short circuit. However, the air in this type of speaker has a damping effect, which affects the maximum vibration frequency and quality factor of the speaker. And because the sound-absorbing material in the speaker consumes part of the sound energy, the sensitivity of the sealed speaker is low.

(2) Inverter speaker structure? The structure is basically the same as that of a closed speaker, except that an inverter hole is opened on the panel of the speaker, and an inverter tube is installed inside the box. The inverter hole Its function is to surround the sound wave radiated by the speaker through the inverter tube and superimpose it with the sound wave in front of the speaker to improve the frequency characteristics and make the low frequency richer, which can increase the sensitivity of the low frequency band by 5dB.