Tangband W3-315D　vented

I put it in psycho sanctual boundary for the time being.



This already got obtained a mysterious ability ? (the first occult speaker in our country )




Don't say "Does it have a really mysterious ability? Then, please let me listen. "

Specification

2.3L , Japanese cypress laminate lumber , Attached board finish , laminate lumber duct 3cm in diameter
4.2cm in length , No acoustic absorption material

　　The basis of the design is to make it in an easy-to-use size because Q can be lowered with the amplifier. Volume of 2.3L is not so bad.

Next, setting a moderate negative impedance because it influences tone quality if negative impedance is greatly taken too much . -2.5Ω is a so-so value.


View of figure

The electromagnetic damping hardly hangs in 130Hz. Because of a strong air spring added
by the resonance of duct , the amplitude of diaphragm is suppressed.And the third distortion
is added .

　The electromagnetic damping and the damping by current positive feedback amounts to
about 20dB in 172Hz (fig.2).

At the first wave and the second wave , the voltage rises in Zo=-2.5Ω , so we see that
the speed control hangs here . This shows that the rising speed has slowed at the
first wave and the second wave (fig. 4).


　In the tuning that the peak cracks to the right in two like this , driving power of the duct
comes enough and the sound turns lucid .
　However, when this is done in a case of a high Q unit , it is too much because of putting
it on with the resonance of diaphragm.

In the figure below (Zo=0ohm ), because the peak of diaphragm has a peak , it is a
disqualification. The sound pressure characteristic of diaphragm,to the last , should have
a decreasing slope as in Zo=-3ohm .




The distortion decreases and some Q rises in the duct resonance when the current positive feedback is put (fig 5,fig 6).

　Another problem is the flapping phenomenon of diaphragm around 80Hz .

　Though　it is safe in the negative impedance amplifier, the waves is greatly distorted
in a conventional amplifier.

　　This was a simple analysis that uses the microphon, but to study precisely on vented
system it is needed to use verosity detection coil .