Does the recommended enclosure volume take into account sub displacement, or do you need to figure that into how big the box should be? I am talking about an IDMAX, and Im not sure if I should build the box 1.3-1.5 cu or build it bigger to accomodate the displacement
Also, what is the advantage over building a sealed box 1.5 feet as opposed to 1.3 feet? Thanks!
The best way to be sure is to use the specs that came with it to calculate the box size for your required frequancy response characteristics. You'll need to know the free air resonance (fo or fs), Q(ts)resonance magnification, and V(as)Compliance. if the 1.5 cu feet measurement your talking about is the V(as)measurement it's not the enclosure volume.
larger boxes generaly have a lower and flater frequancy response. but this is directly dependant on the speakers specs going to far from the ideal for the speakers specs can make a good quality speaker sound bad.
The specs for the ID Max is gross volume, which you don't need to take account for the driver. Just build a 1.3 cu ft gross sealed box. A 1.5 will offer a little more cone excursion and increased bandwidth (will drop lower), and lose a little tightness.