Audio Speaker Design

Rumus untuk Menghitung  Volume dan Port Dimensi

 

Driver Parameters

Ro = Rmax / Re
Rx = Re * ( Ro )^1/2
Qms = Fqr * [( Ro ) / ( F2 – F1 )]^1/2
Qes = Qms / ( Ro – 1 )
Qts = Qms / Ro
Sd = 3.14159 * ( Dia / 200 )²
Cms  =
[ 1 / ( 12.56636 * ( M / 1000 ) ) ] * [ (Fqr + Fqs) * (Fqr – Fqs) / (Fqr² * Fqs²) ]
Vas = 140000000 * Cms * Sd²
EMP = Fqs / Qes
L = X / 6283.18         X = ( R² – Re² )^1/2

Sealed Enclosures

Qts = Qes * Qms / ( Qms + Qes )
Fcb = Fs *  [ ( Vas / Vb ) + 1 ]^1/2
Qtc = Qts *  [ ( Vas / Vb ) + 1 ]^1/2
db = 20 * log₁₀[ Qtc⁴  / ( Qtc² – 0.25 ) ]
Fdb = Fcb * [1 – ( 1 / ( 2 * Qtc² )]^1/2
F3 = Fcb * [ ( a + (a² + 4)^1/2 ) / 2 ]^1/2
       a = [ 1 / (Qtc * Qtc) ] – 2

Dual driver
Qes = Qes / 2
Vas = 2 * Vas

Quad driver
Qes = Qes / 4
Vas = 4 * Vas

Vented Enclosures

Vb = 15 * Vas * Qts^2.87
Fb = 0.42 * Fs / Qts^0.9
F3 = 0.26 * Fs / Qts^1.4
db = 20 * log₁₀ [ 2.6 * Qts * ( Vas / Vb )^0.35 ]
Recalculations
Fb = [ Vas / Vb ] ^0.32
F3 = Fs *  [ Vas / Vb ] ^1/2
Single port
Vb_in = Vb * 61.016949
R_in = 0.393701 *  Dp / 2
Lp_in = [ ( 14630000 * R_in² ) / ( Fb² * Vb_in ) ] - [ 1.463 * R_in ]
Lp = Lp_in * 2.54
Dual port
Dp = [(Dp * Dp) + (Dp * Dp)]^1/2          - for calculation of Lp
Dual driver
Qes = Qes / 2
Vas = 2 * Vas
dd = 68600.0152 / Fqx

Dimension calculations

y = [ (Vb * 1000) + (Vdr * 1000) / ( 1.618 * 0.618 ) ]^1/3

W = y
H = y * 1.618
D = y * 0.618

3rd order 2 way Butterworth crossover

C1 = 106103 / ( Fc * Rt )
C2 = 318391 / ( Fc * Rt )
C3 =  212207 / (Fc * Rw)
L1 = 119.37 * Rt / Fc
L2 = 238.73 * Rw / Fc
L3 = 79.58 * Rw / Fc

1st order 3 way  crossover

ratio = Math.round [ ( FqH / FqL ) – 1 ]
FqL2 = ( FqL *  FqH / ratio )^1/2
FqH2 = FqL * FqH  /  FqL2
C1 = 159155 / ( FqH * Rt )
C2 = 159155 / ( FqL2 * Rm )
L1 = 159.155 * Rm / FqH2
L2 = 159.155 * Rw / FqL

Attenuation network

Rp = 10^db/20 * Rt / ( 1 – 10^db/20 )        
Rs = Rt – [ ( 1 / Rp ) + ( 1 / Rt ) ] ^–1

Impedance compensation network

Rc = 1.25 * Re
C = 1000 * Ld / ( Rc * Rc )

Please see the Online Enclosure Calculators for definitions of variables.