Exceeding recommend box size?

[Swordlordboy1234]

The 3.2 cubes is after raising the seat 2.5 inches. And that's based on an outifre box not a downfire. Downfire costs a lot of volume because of the space needed between floor and sub.

Since you have space to kill I would say try to down fire the subs. I have had great success with the subs and port 90 deg out of phase with the subs loading on the floor. So a sub down port forward under the seat box?

Also 800RMS on 2 SA 8's i think that is under powering a little but that would be fine. Another factor in terms of subs is how power vs box size works together. Theoretically you could run less power and build a larger spec box and still get the subs to the proper peak to peak throw for optimal output.

Anyways. Play around with numbers and see if a 2 8's down fire ported box would work for you bud.

[Robert Harrell]

I have 4 Sundown 12in. U's in a  2012 Chrysler Town & Country With   82.3 in³ it is With  Is 3rd row laying down And using  A sundown  salt 4 Amp   Is in a ported Box 2 and a 1/2 ft³  4 each Woofer  What I'd like to know is  Is a enough airspace for them and And is the sundown salt for a strong enough

[audiofanaticz]

This is a under seat box I built last summer for a guy with a pair of the newest X-8's on a Sundown SFB-2000 in a 05 GMC Sierra without doing a seat lift.
I built the box a tad larger than spec (cant remember exact size I would need to find my box plans if I still have them) for increased efficiency and to get tuning a little lower than due to limitations on the port length. No issues what so ever. Granted going larger then recommended can turn to a nightmare fast if you don't know what you're doing or know what to listen for mechanically wise on the sub(s).
So for the SA-8s if they are the V3 series I probably wouldn't go anything larger than 0.4 - 0.7 cubic feet larger for both subs together. So ideally 1.9 - 2.2 cubic feet after sub/port/bracing displacement is subtracted for your 940ish watts you have. If you go too much larger than that you could potentially run into unloading issues but its hard to say since your not giving the subs their full rms wattage.