i just got some ma audio subs and the book recomends 2cuft@40hz. is this ok? i was lookin at some box plans on here and they all seem to be down around 32 to 35 hz. so my question is, i will be goin to a few local sound off days for some spl and want these to really get with it. is there anyone here that can tell me what i should do? go with factory recomendations or is there somethin better?