It is the most popular
design. When the diaphragm of the speaker generates sound, the sound
waves which are reflexed from the rear board will be sent out by
the reflex pipes. The size and length of the reflex holes and pipes
all affect the extension of low frequency, therefore according to
the character of the speaker, we should design proper holes and
pipes in order to get the best speed and the extension of low frequency.
The enclosure is entirely
sealed. This design will decrease the operating efficiency even
though the low frequent voice is good. Therefore in order to get
better control, we must give high power to operate it or the speed
of the low frequency will be delayed.
A kind of closed enclosure,
mainly adds another low frequent speaker. When it vibrates to generate
sound, the passive radiator diaphragm is pushed by air. The disadvantage
is low efficiency and speed.
It is able to increase
the low frequent energy, but the closed design causes the low efficiency.
When the two speakers work at the same time, if the sound is out
of phase, it affects the results as well.
The transmission line
enclosure extends the low frequency by a long wave guide; however
the over-length of the wave guide may lower the speed of the low
The enclosures we introduced
above can not be completely applied in all the electronic products,
it is for consultation; we need to face and solve more problems