Can Someone Calculate My Frequency?

[bcarpenterfhl]

I tried to do it myself, and got a different figure than Bassbox Pro. I just wanted double check it before i make all my cuts.

Box Volume: 3.648 ft.^3
Slot Width: 2.5 in.
Slot Height: 14.5 in.
Slot Length: 21.125 in.

[Damaso87]

http://www.caraudio.com/vb/showthread.php?t=68635 <- Start pluggin numbers in

[bcarpenterfhl]

i'm getting all different answers for the audiobahn.com calculator, the12volt.com, and bass box pro. can someone whos good with this stuff figure out the frequency with from the information previously given. im trying to achieve a frequency of 33.7 Hz. and the only dimension that can change is the port length.

[g30ffr3y]

with a slot that wide your going to need a hell of a lot longer port... me thinks...

[bcarpenterfhl]

ok change of plans. i want to widen the vent to 2.75 inches. so my new vent dimensions are:

w: 2.75 in.
h: 14.5 in.

bassbox pro says i need a port length of 24.68 inches to achieve a frequency of 33.7 Hz. (fyi this decreases my Vb to 3.483 in.) but audiobahn.com says i need it to be 19.35 inches. i just thought of something. Bassbox Pro takes into account port displacement, perhaps adiobahns calculator doesnt?

[bcarpenterfhl]

can someone please verify my Bassbox Pro calculations?

[DBfan187]

ok change of plans. i want to widen the vent to 2.75 inches. so my new vent dimensions are:

w: 2.75 in.
h: 14.5 in.

bassbox pro says i need a port length of 24.68 inches to achieve a frequency of 33.7 Hz. (fyi this decreases my Vb to 3.483 in.) but audiobahn.com says i need it to be 19.35 inches. i just thought of something. Bassbox Pro takes into account port displacement, perhaps adiobahns calculator doesnt?

BB6P takes the subs displacement into account. That's why it's longer. The online calcs don't.

[bcarpenterfhl]

oh ok thanks a lot.

[bcarpenterfhl]

why not?

[bcarpenterfhl]

f**k! this is becoming so complicated. then whats the poinit of their slot feature?

[bcarpenterfhl]

can anyone tell me how to calculate a slotted port displacement?

[bcarpenterfhl]

oh ok thanks, so that means it probably wont even calculate my frequency right cause it cant get an accurate displacement of the port, huh?

[bcarpenterfhl]

ok. i get Cs in math. can someone please help me out. The slot height needs to be 14.5 in., the width 2.75 in. The total box internal volume w/ driver displacement is 4.255 ft.^3. all i need to do is figure out the port length the achieve a tuning of 33.7 Hz. I've tried m best on this, and havent been able to figure it out. can someone please help me out?

[bcarpenterfhl]

i know, i did that, but then my frequency changed. i dont know how to get my frequency with the port length b/c everytime i put in the port displacement, the volume changes, thus changing the frequency. im just having so much trouble figuring out something that should be so simple.

[DBfan187]

Design the box first.(Before entering in the subs specs)