hi i just want to know that why wood is used to make the speakers ?why
not plastic?
Note that you can find many "mini stereos" that have plastic boxes
for the speakers. And of course, any boombox uses plastic.
It's not so much the material, as the quality. Cheap wooden speaker
boxes will rattle and shake, while strong wood boxes won't. Cheap
plastic, and the same problem, strong plastic less likely. Metal
can have its own problems, but also done properly make good speakers.
Apart from anything else, wood is an easy material to work. Plastic
requires a process that isn't so economically feasible unless you
are making a lot, the setup costs is too much.
In the old days, when there was a variety of hobby electronic magazines,
speaker construction articles were common. All kinds of material were
used. Cardboard boxes, though they were reinforced and sealed up
well. Concrete sewer pipes. Ironically, some of those could afford
to use out of the ordinary things that supplied a nice strong box,
because unlike commercial endeavors, shipping the heavy materials
was not an issue, and someone building their own could live with what
others might consider "ugly".
The box in itself means nothing. It's there to make sure the sound
comes out of the front of the speaker (and any port, if there is one),
rather than from all over. You don't want the box to get in the way
of the sound (or want the effect to be as limited as possible).
Michael