Before I explain my question I want to say I know WinISD is not going to accurately represent the output in a car, I am just using it to get a general idea of the frequency response shape of the box itself. I am trying to help a friend decide on what subs to get for his new setup. I am strongly pushing a pair Fi 12's and he asked me to design a box for him. With most drivers I put into WinISD a get reasonable looking response curves when putting in the recommended enclosure specs, and then I go on and alter designs from that point. With a pair of Fi Q 12's I started with a 4.2 cubic foot box tuned to 32Hz and this is the shape of the response I got... I suspect it is because of the low Vas that the Fi Q's have. But if the Vas is so low, why can't the box be much smaller? I am just trying to make sense of this graph and the sub-woofers Vas. On an off-note, how do you think the subs will perform in a 4.2 cubic foot box tuned to 32Hz? Thanks for any help.
