Need help with calculations from Ported box Sticky

[ultimate157]

Vd = Sd x Xmax (Where Sd = surface area of cone?)

Sd = 3.372^2 * 3.14 = 35.76
Xmax = 0.45 inches

Vd = 35.76 * 0.45 = 16.092

Now, as soon as I try to calculate required port area, with tuning of 35hz


dV>/= 39.37*(Fb*Vd)^0.5

dV = 39.37 * (35*16.092) ^ 0.5
= 39.37 * 23.73
= 934 sq inches of port area ??

[berserker]

Fi SSD12 used for reference.


Vd = Sd*Xmax


Vd = Sd (M^2) * Xmax (Meters)
Vd = 0.048 * 0.021
Vd = 0.001008


dV >/ 39.37*(Fb*Vd)^0.5


dV >/ 39.37 * (Fb*Vd)^0.5
dV >/ 39.37 * (35*0.001008)^0.5
dV >/ 39.37 * 1.878297101
dV >/ 7.394855687
dV >/ 7.39


A = Pi*R^2


A = Pi * R^2
A = 3.142 * 3.695^2
A = 42.89870455
A = 42.90




And you end up with 42.90 In^2 minimum vent area with tuning of 35 Hz.

[ultimate157]

Ahh ... thank you. I didn't see anywhere in the sticky that said what units to put them in.

[berserker]

You are welcome and I believe it doesn’t from what I have seen skimming through it just before doing this for you.

[ultimate157]

You are welcome and I believe it doesn’t from what I have seen skimming through it just before doing this for you.


Lv = [(1.463*10^7R^2)/(Fb^2*Vb)] - 1.463

How about this equation ... 1.463x10^(7R^2) ..... comes out to be a number to the 40th power.


BTW: Numbers I'm using are:

for a TS/W106DVC Pioneer Premier. Have it laying around and I want to build a ported box for it.

Fs 35.4
Qms 10.46
Qes 0.52
Qts 0.5
Vas 0.955
Rms 2.453
Mms 115.49
Cms 1.8x10-4
Diam 7.9in
BL 17.62 (8Ohm)
8.81 (2Ohm)
Xmax .45in 11.5 MM (0.0115 meters)

[bholtmeier]

Fi SSD12 used for reference.


Vd = Sd*Xmax


Vd = Sd (M^2) * Xmax (Meters)
Vd = 0.048 * 0.021
Vd = 0.001008


dV >/ 39.37*(Fb*Vd)^0.5


dV >/ 39.37 * (Fb*Vd)^0.5
dV >/ 39.37 * (35*0.001008)^0.5
dV >/ 39.37 * 1.878297101
dV >/ 7.394855687
dV >/ 7.39


A = Pi*R^2


A = Pi * R^2
A = 3.142 * 3.695^2
A = 42.89870455
A = 42.90




And you end up with 42.90 In^2 minimum vent area with tuning of 35 Hz.


Where did you get 3.695 from?

[ultimate157]

Where did you get 3.695 from?

dV is the required port diameter. R = 1/2 of the diameter. 1/2 of 7.39 = 3.695

[bholtmeier]

Required port diameter?

[ultimate157]

bump ... anyone have an answer to my 2nd question ?