95Probite

well im making a ported and sealed box for my hatchback . but first im trying sealed then build a ported. now here are my specs and my calculations. would someone be kind enough to double check these numbers? its my first time building and i want to make sure i have it right.im trying to find the internal volume. thanks a lot!!


Vas- 1.95 cu.ft/ 54.93 liters
Qts- .31

Qtc- 0.707 ( i seen this number was highly recomended)

Fs - 25 - but i dont think this number matters in this equation to find the total cu.ft. not sure

sub displacement - 0.0089

Vb = 54.934L/((.707/.31)^2-1) = 13.075L

Then you convert that to cubic feet which is 0.462cuft

TOTAL- 0.462 + 0.0089 = 0.551 cu.ft PER sub

it seems so small. could this be correct?

2 8's AKA Jeepbeats

iTrader: (19)

28.32 Litres is equal to one cubic foot. If you post the L/W/H dimensions of the box(es) it would be easier to help you out.

95Probite

but isnt the equation that i posted, the WAY to find the INTERIOR space excluding the wood?? after i know the proper space, then i will mess around trying to get the box to fit properly in the car with the H/W/D dimensions. see what im saying?

[ May 29, 2005, 07:05 PM: Message edited by: 95Probite ]

2 8's AKA Jeepbeats

iTrader: (19)

What is the make/model/size sub that you are using? The VAS that is given with each speaker is not necessarily the size of box required, as far as I know. http://www.bcae1.com/spboxad2.htm

95Probite

hi jeepbeats. well if im not mistaken, the equation that some other box builders told me to use is this:

Vb = Vas/((Qtc/Qts)^2-1)
or
Vb = 1.94/((Sqrt(0.5)/0.31)^2-1)

both turn out the same result. Sqrt(0.5)=.707

Now i know that the VAS is different on all subs, but all i did was enter the specs and calculated what it says to calculate.im not saying the volume is the same as my VAS. the final number i got was 0.462 cu.ft BEFORE sub displacement.

VAS = 1.95 cu.ft which is also 54.93 liters
Qtc = I choose to use .707
Qts = .31

thats all i should need as far as numbers are concerned, correct??
does anyone see any flaws?

2 8's AKA Jeepbeats

iTrader: (19)

If you give me the make/model I can run it through my program and double check.