What is a subwoofer? What's the difference between it and a speaker!

The subwoofer works exactly the same as an ordinary speaker, except that the diameter of the diaphragm is larger, and a speaker for vibration is added. The frequency band played back by a subwoofer is usually from the upper limit of 150Hz or 100Hz to the lowest of about 25Hz. It is usually called a "subwoofer" in commercial or civilian applications (the upper limit of the so-called subwoofer in multimedia speakers is as high as 300HZ or even 3000HZ , in fact, it can no longer be called a subwoofer). From a scientific or professional interpretation point of view, in fact, only frequencies below 20Hz can be called "super" bass, because frequencies below 20Hz are music that exceeds the human ear. range of bass. But generally speaking, the subwoofer refers to the bass whose playback frequency is lower than 20Hz. When replaying dynamic music or movie sound effects, subwoofers are more important than traditional floor-standing stereo speakers. This is because the special sound effects included in many pieces of music (symphonies or harp and drum music) and many movies are extremely majestic and dynamic bass. This sound effect is not just meant to be "heard" by the listener, but It is even more important to let them "feel" the atmosphere of this situation.

Subwoofers are mainly divided into two categories, they are passive (PASSIVE) and active (ACTIVE).

For passive subwoofers, the left and right main speakers are full-range, and the subwoofer only sounds when the bass below its upper frequency cutoff point appears. This kind of system is called a connected subwoofer system. For example, the playback frequency of the main speaker is attenuated below 65Hz, and the subwoofer's dividing point is around 65Hz.

In the active ACTIVE (dual amplifier) ??subwoofer system, the signal goes directly into the preamp with active crossover. Frequencies below 100Hz are amplified by the bass amplifier and sent to the subwoofer speaker for broadcast. Frequencies above 100Hz are sent to the rear stage of the main speaker after frequency division, and are amplified and played out by the main speaker.