Exists speaker cabinet purpose - mainly to prevent the positive and negative speaker diaphragm acoustic signal directly form a loop, resulting in only a very small wavelength can spread out high-frequency sound , while other sound signal is superimposed offset out. Speaker of the physical model is an infinite rigid baffle open a hole , install the speakers, so we can guarantee the positive and negative speaker sound signal does not form a loop, causing sonic loops.
However, the actual use, the speaker can not be made is infinite , so people behind the speaker baffle plate is formed with a closed space , ensuring positive transmission of sound waves . The question then arises : Speaker sealed after the atmospheric problems, speaker box is bigger and more conducive to low-frequency sound reduction , so the volume is based on the general speaker woofer speaker size calculated from a data compromise .
Environment is not allowed to have too many of the box , in order to further reduce the size of it , and according to the characteristics of sound waves and enhance low-frequency sound reproduction requirements of the design of the baffle box , inverted tube , the cavity , mainly in order to in the frequency band of a certain wavelength of the sound signal are enhanced and atmospheric pressure to further reduce the influence of the sound reduction .