How to obtain Fd

Basal condition + China plywood + FE103E

    I will write obtaining from the how to request it and expression because I obtained Fd of last BS-10 (frequency radiated from the duct) though it is a difficult material for a moment.
As for the numerical value needed when the [basurefu] type speaker is designed, three points of the length of the sectional area of the size of the cabinet of the speaker (Vc: unit?) and [basurefudakuto] (L1�~L2 is converted into the area of a circle and the radius is put out: When the sectional area of unit cm�� (example) port is 30^cm2, a is about 3.1) and [basurefupo-to] (L3: unit cm) become the most important elements. Let's assume setting to for the time being these though the problem of installation position, how to bend it, yen of [basurefupo-to] or square pillar is also important.
The above-mentioned three points (Vc,r,L3) are substituted for the following expression.

The following is understood from this expression.
If r ,in a word, the sectional area of the duct is enlarged (Reduce it) and Vc and L3 are constant
      ��Fd shifts in the direction of a high region. (Shift in the direction of a low region. )
..Vc or L3 ,in a word, the content of the box product.. if it ..duct.. ..length [wowo].. enlarges (Reduce it) and r is constant
      ��Fd shifts in the direction of a low region. (Shift in the direction of a high region. )

BS-10