john253a

for 4 15" you need 10-14cuft net as a standard box with your dimensions its 11.xx gross and 8.xx net as in pic that 7.xx gross about 5net with aero port, that only enough volume for 2x 15" you either need to use less sub ie 3x15 in a standard box drop down to 2 or choose different subs

its not fitting the subs in, as they will fit like that easy, it the net volume you need

just run 2 set of components in front door and a set of stanard 2 way in the back

12x 8 inverted or half in half out

It's also avaible in the sticky section of this section

could do 6x 10" or even 8 maybe even get away with 6 12" or 10-16 sa8v2 in a better designed box When you chose smaller sub the flat side is smaller and will increase box size you may be able to get 9gross if for 10"s and 8"

Your doing subs up port back yes

7.4 gross 4x 12 2x 15 maybe 2x18 could even do aero ports

4th order at 2:1 for 4x15" will require around 6-8cuft net sealed and 12-16 ported, thats 18-24cuft net, in 12gross idd say only 2 are going to fit

no way not gonna fit as 1 soild box with port your only at 9 cuft net once you split it your going to be down around 4-5 net thats no were near enough for 4 15"

is that 2 boxes the same as above or 1 that box is only just big enough as is let alone once split

the only problem i see is the 28" high 2x 15" = 30-32" and wont fit in height i see you say horizontally, how do you plane to do that with 25 deep and 36 width that still only = 2x 15"

Does the 125.4 have built in subsonic filters As that amps will look nice stacked side by side 1 for subs 1 for surrounds 438x2 @4 is nice power for 2 sa8

they increase the efficiency of the port, same as a flare does on PVC

And how much you want to spend

List the space have available an diamensions The amp you have to power it + specs What feq you want it play Also if it drops out abit higher look at good set or 2 of surounds to balance it out and pick up where it droped off An active set of 3 ways will help out 8" + 5.25" components Or 2 sets of 6 or 6.5 components

thats the box not the sub tune it right and it will play everything

why not do port up?

if you do a 2x common walled, L-port on drivers side 8" x 8" x 26" long if box is 15x45x18 4cuft net 34.2 hz 1 common wall C-port (bottom middle) 4"(h)x 15"(w) x 26" long 4cuft net 33.9hz

ran some numbers 4x 3" no way you will get port noise and will sound like crap 4x 4" on the other hand is the min idd run but 2x6" 22-25" long would be ideal

In this section, where the sticky posts are, there is a post called Torres, in there, there is a program in the first post called Torres, download it and play around with it, I'm mobile at moment so can't run the numbers for you.

dam i just got my sa8 shipped 1/2 round the world to australia, at-least if the x8 were available it would have made it more worth my wild when freight is 2.5x the purchase price