The problem here (though not insurmountable) might be that you have to match the volume to the open-backed drivers that you use. In this case you'd be starting by defining a volume of air.
Every driver has a set of paramenters known as the 'thiele-small' paramenters. On this list of parameters is one known as "VAS" which is the volume of air required inside the enclosure. You can make a box "appear" about 15% larger than it is, by using wadding/batting inside, but you really have to be close to begin with. Remember also that this 15% is an equivalent volumechange, not an equivalent linear measurement change... therefore if you need 11½litres , you can use 10 litres and wad it carefully. If you have something 10cm x 10cm x 10cm, you can't wad it up to 11.5cm x 11.5cm x 11.5cm... there's a really big difference!
Usually you pick the driver and builc a box to suit how much volume you need... you're working kind of "backwards" this way. ...-You might get lucky, but you can't regularly work this way and count on being lucky all the time!
Keith