Speaker pursuit road > relation and the top of unit and enclosure >

(3)What is [zai] that is appropriate for the enclosure?

  When the kind of the sound described in the previous paragraph is arranged, the speaker system [karaderu] sound is a sum total of the following three sounds.


Direct sound radiation from sound A= unit
Sound reverberant sound of enclosure that transmits vibration from sound B= unit and sounds it        (one of indirect sounds)
It vibrates the reaction of the sound of sound C= enclosure by the obstruction of an accurate vibration of the unit.
      (Sound B and sound C are quite the same essentially and think separately here. )

  Sound C harmful to design the speaker will not wait for the theory. It goes away from the idea of high fidelity solving ..so.. though it is not separately black even if sound C is admitted goodness, and there is an idea of positively using it, too. Sound C will be assumed to be an idea that the idea of reducing it as much as possible is a basis of the speaker design, and it pursue the subject by the viewpoint how sound C can be reduced here.

    To exclude sound C(vibration that disturbs the vibration of the unit), the unit should be able to be fixed firmly first of all and to be maintained. In a word limited strength, hardness, and weight are necessary materials. However, hardness is strong strength, and if it is not odd but weight is abnormally heavy, not good in it alone. Let's think as an example of iron. Iron is not used as a speaker enclosure though are compared with the general plywood used for 7.85 in the specific gravity and the speaker ten times or more the specific gravity and there is serious weight. The vibration doesn't stop, and the reaction affects the unit negatively if it says why. Then, if what [zai] is used, whether the vibration of the box of the unit can be suppressed uses "Material with high internal loss". Is the material that absorbs the vibration easily to be brief good for ,in a word, other energy the material deflecting as for the vibration an internal loss in changing (It is a thermal energy here) it with a high material?This is called a material with low Q value.

  The main style is still wood though various one such as the cardboard, rubber, concrete besides wood, the glass, and iron is thought ..[wareru] [zai] in the speaker enclosure ..use..... In this, it is height, easiness of an internal loss of wood to treat, and economically low-cost etc. are the main reasons. By the way, a lot of pulps to make the tree a raw material by the reason that an internal loss is high are used also for the vibration version of the unit.