You're sort of putting the horse before the carriage...

To figure the box size you need to know what subs you're using.

Knowing which class you want to compete in is also very important. [img]graemlins/thumb.gif[/img]

 

A good starting point would be either getting or having access to a meter

 

A good starting point is anywhere.

Test and go up or down.

For street A I doubt you'll get bigger than 4-5 cubes.

X

 

if you get a sckool bus than would it be a or b [img]graemlins/dunno.gif[/img]

 

neither. a skool bus is a commercial vehicle, cant use those in street.

 

You'll actually find there isn't a whole lot of difference other than the tuning of the box. A lot of loud boxes are loud in any vehicle, just plays a different note.

 

I saw Don is Saskatoon with a single 10" in his van. The box was about 20 cubes. It was some kind of funky transmission line with a very long port. It was very loud for 1 10" sub.

A big box with a big port is as good a place to start as any. Build a few different size boxes to point you down the right path.

 

With a large vehicle, you have less compromise to do as far as enclosure size, shape and location. It allow you to use a larger enclosure, and woofer that take advantage of this enclosure, to in the end, get a much more efficient setup. With street A setup, you don't need a very large enclosure to get very loud (4-5 cuft, like Xiph0id said) so using a large vehicle is less of an advantage that in a street B setup, when you can take advantage of a twice as large enclosure, wich won't fit in most compact car. I bet you can be competitive nationwide with an SUV in street B

 

i say build your sub box the size of a normal full grown mans coffin, and see how it sounds.