The current family theater elevates temperature gradually, starts the stride to enter common people's family, the video and music equipment factory promotes the AV casing which in abundance is composed of 5 speaker boxes, has reaches 6 speaker boxes to compose, 1 which increases for the overweight bass speaker box (popular name bass artillery). The acoustic magazine person many only introduced that its manufacture and suspends the position method. But consumer whether to need the bass artillery? Let us have a look at its principle of work first. Dubi surrounds sound Pro the Logic system to have 4 sound tracks: Before first left (L), right (R), sets at (C) and surrounds the (s) sound track. Surrounds the sound track, although has used 2 speaker boxes, but this 2 surround the speaker box in fact is actuates by the identical road signal. Sometimes in addition, this kind of system will increase 1 overweight bass speaker box, but will actuate its signal not to be independent exists in the primary signal, but will use the frequency division the method to separate from the LR sound track. Therefore, although sometimes this kind of simulation encirclement sound system will provide reaches 6 sound boxes, but its primary signal will actually have 4 groups. the bass artillery's function is exudes the strong bass effect sound (for example explosive sound, cosmic rocket's bellow and so on), strengthens shocks the strength and the theater effect. Regarding Dubi Pro Logic system. The system, this sound box is may elect, but regarding digital coding's AC-3, THX5.l and the DTS system, it is necessary. when match family theater AV casing, should according to the seeing and hearing space size and whether to have the sound-insulated facility to decide whether to dispose the bass artillery. The author in one approximately 15 square meter ordinary room auditions "Real Rumor", "007 Gold Eyes", "Breaks Arrow" and so on famous testing big piece, felt that the bass is too rich, the obvious pollution, extremely easy to create listens wearily. But switches off the bass artillery, the acoustic fidelity is clearer, has the position feeling and the surrounding feeling. present market Av power amplifier mostly only then ultra bass voltage signal output, needs to dispose the active bass artillery, but the active bass artillery is expensive, good spot brand retail price above 800 Yuan. Therefore the author suggested that regarding only then 15 square meters below, also does not have the sound-insulated facility seeing and hearing environment, when chooses the AV casing, is not suitable disposes the bass artillery, the available purchase bass artillery's fund, selects and purchases the AV casing which a set of performance-to-price ratio higher 5 speaker box composes.