1. Speaker classification
These speakers have different characteristics due to their different structures. These speakers are divided into three categories according to major categories: one is open type, the other is closed type, and the third is inverted type. Among them, the inverted speaker has the most variation. For example, the labyrinth is the deformation type of the inverted speaker.
2. Enclosed speaker
This kind of speaker is characterized by its simple structure. Except for the speaker hole, there are no other holes on the cabinet and it is in a fully sealed state, so it is named a closed speaker.
The front and back of the speaker cone in the closed sound box is divided into two impermeable spaces. One is the infinite space outside the box, and the other is the space inside the box with a certain volume. The walls inside the box are covered with suction. Acoustic material.
When the speaker vibrates back and forth, the sound in front of the paper cone radiates outwards, and the sound behind the paper cone is absorbed and blocked by the sound-absorbing materials distributed in the box and cannot be transmitted to the outside of the box, so that the sound waves in the box and the box External sound waves cannot interfere, thereby improving the low-frequency characteristics of the speaker.
3. Inverted speaker
Open another sound outlet (also called an inverted hole) on the front panel, and add a sound outlet (also called an inverted tube) behind the sound outlet. Figure 5-73 Schematic diagram of the structure of an inverted speaker
The phase-inverted speaker inverts 180 phases of the low-frequency component sound waves radiated from the back of the speaker cone. , Radiate to the front through the inverter tube and the inverter hole. Since this sound wave has been inverted, it is in the same phase as the sound wave radiated from the front of the speaker cone. In this way, the two sound waves have an additive relationship, which strengthens the low-frequency sound wave radiation and greatly improves the low-frequency radiation sound pressure level. Inverted speakers are widely used.