IgnoreMe

11-14-2004, 01:17 PM

ok well im tryin to design a box for 2 15" sx's. its gonna be 7ft^3 @ 35 hz.

port is 17.5*6=105" sqr

17.5" high

39" wide

21" deep

pLV=21.5

21.5-11.5(any number like in my tutorial)=10 so 10" is the imaginary length of the 2nd wall

10*6.75*17.5/1728= .6835ft^3 (displacement of 2nd wall)

10-6=4 (so 1st wall imaginary length is 4")

4*6.75*17.5/1728=.2734ft^3 (displacement of 1st wall)

.6835+.2734+.36+7=8.3ft^3 (gross volume)

8.3*1728/(17.5*39)=21 (internal depth)

21-6= 15 (true 1st wall length)

now HERE is the kicker

21.5(plv)-22.5(interal depth+1.5)= -1

hmmm how do i get a wall length of -1 and how do i fix it? i checked over my math and REDID it about 3 times and come up with the same answer each time. any sugestions? if not i got a back up box @ 32hz so its all good but im still clueless as to why i get a negative number for the 2nd wall length

port is 17.5*6=105" sqr

17.5" high

39" wide

21" deep

pLV=21.5

21.5-11.5(any number like in my tutorial)=10 so 10" is the imaginary length of the 2nd wall

10*6.75*17.5/1728= .6835ft^3 (displacement of 2nd wall)

10-6=4 (so 1st wall imaginary length is 4")

4*6.75*17.5/1728=.2734ft^3 (displacement of 1st wall)

.6835+.2734+.36+7=8.3ft^3 (gross volume)

8.3*1728/(17.5*39)=21 (internal depth)

21-6= 15 (true 1st wall length)

now HERE is the kicker

21.5(plv)-22.5(interal depth+1.5)= -1

hmmm how do i get a wall length of -1 and how do i fix it? i checked over my math and REDID it about 3 times and come up with the same answer each time. any sugestions? if not i got a back up box @ 32hz so its all good but im still clueless as to why i get a negative number for the 2nd wall length