Why do subwoofers need a box but midrange and tweeter or coaxial 2way don't?

3 Answers

  • Favorite Answer

    Without the enclosure, the woofer will only produce about 10% of bass. With the enclosure, that's how a woofer finish's building up. The woofer needs a good proper built quality enclosure to produce HARD and LOUD.

    A human's hearing frequency is 20hz to 20kHz and the woofer uses low-end frequencies around 10hz to 500hz.

    The amplifier's LPF should be set at about 80hz to cut the woofer down to 80hz because we don't want the woofer bumping up to 500hz. The bass boost should be set OFF. The subsonic is set on how low you want the woofer to get. Most people have the subsonic set at 25hz to 35hz. The gain should be set to the output signal on the head unit or whatever the amplifier's RCA input is connected to.

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  • 4 weeks ago

    Coaxials do have boxes -- they're just very large boxes -- Trunks, doors, etc.  This is called an "infinite baffle" system in that the enclosure is infinitely large in relation to the speaker's parameters.  Some subwoofers will operate in this configuration as well, but typically something in the 1-4 cubic foot size works much better.

    The reason speakers need a baffle of some kind is because as the cone moves the pressure wave created by the front of the speaker is created by the back of the speaker as well, but it is 180 degrees out of phase, so the net output would be zero.  The wall of the box isolates the waves which allows the speaker to produce clear sound. 

    • The Devil
      Lv 7
      4 weeks agoReport

      There is some degree of wave cancellation, but it can never result in a zero output result. The resonance of the box (reflex systems) helps emphasize and bolster lower frequencies and increase efficiency of the system. You know that, I'm sure.

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  • Robert
    Lv 4
    4 weeks ago

    Physical size of subwoofers makes them difficult to house within most vehicle interiors. Another problem is resonance, with the power levels that most subwoofers operate at. Can't imagine if the parcel shelf by itself is used as it may lead to very bad coloured reproduction.

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