FI xv4 12s in 4.5 net cubes help

[MDdrolman]

Hello,

 

Toyota Camry SE, Two sets of dimensions.  One is with enclosure pushed as far toward back seat as possible, the other is with enclosure pushed closer to trunk latch which gives me width.

 

MAX dimensions 44" width(left to right facing trunk, 18 height, 24 depth

                             38" width, 18 height, 31 depth

 

I have been designing an enclosure with subbox pro and WINISD.

 

I have 2 FI xv4 12s.

I would like around 4.5 cubes net tuned to 32 hertz.

 

When designing it, the only way to get a port velocity below 22(forgot the units) is by having a 7" wide slot port which gives me 95"2 of port.  

 

can anyone help me out with my design please.  I may be completely overlooking something.  I am open to suggestions on any aspect of the build.

 

ALSO:

 

I have an enclosure for 2 12s.  They were JL w3v3 12s.  I built the enclosure exactly as the  JL tech designed it for me.  It is 3.5 cubes net tuned to 32 hertz.  My main concern with using those is it is at the minimum size requirement per FI which is 1.8-2.5 cube per sub.  My next concern is port area which is 2" wide, 12.5 tall, and 13.5 deep(into sub enclosure).  I feel like such a small port area wont be adequate port velocity wise.  Do you think its worth even putting them in my current enclosure, or just building one a little more suited to these subs.

 

Thank you for any help.

[revoracing247]

only suggestions I'd add is watch out with the dimensions that you can actually install/remove the box lol especially with the wider dimensions. though the one pushed to the seats actually nets more ft^3 and i assume you could just slide it through the opening after folding the seats. Just something easy to overlook when designing stuff.

Also looking up the subs, i really don't like their combined T/S perimeters for D1 and D2 subs. they have the big ones separated, but the wire weight difference between D1 and D2 will change FS and suspension compliance and what not. That is assuming they're using the same gauge wire between the two. but even if the VC do weigh the same, the Inductance (Le) difference between the two will also affect Qes too. So if you're really trying to design this enclosure for the subs, then breaking in the subs and measuring actual T/S values might be a good first step before deciding on a box design through WinISD.

As for the port velocities, first off glad you're even looking at it, and second isn't there graphs for cone excursion in there too? So you should be able to get an idea if that port area is too much or two little to give the control needed for those subs on the power you plan to run.

Overall, you have the other enclosure... if you're willing to be patient, then model that enclosure with the FI subs in it, then stick them in and see if the modeling matches your actual's for your car. might give you more info to make better choices with the enclosure designed for them in that car. Just be careful on mechanical and electrical limits while in the JL box (as the subs might unload at odd frequencies and what not). but usually it'll probably just sound like crap and have a lot of distortion from port chuffing or otherwise. but giving the subs the min ft^3 spec'd by the manufacturer won't make them suddenly catch fire or something. especially if you're not pushing the power limits of the FI subs.

Hope some of that helps haha

[Joe X]

On 6/22/2025 at 12:17 PM, MDdrolman said:

Hello,

 

Toyota Camry SE, Two sets of dimensions.  One is with enclosure pushed as far toward back seat as possible, the other is with enclosure pushed closer to trunk latch which gives me width.

 

MAX dimensions 44" width(left to right facing trunk, 18 height, 24 depth

                             38" width, 18 height, 31 depth

 

I have been designing an enclosure with subbox pro and WINISD.

 

I have 2 FI xv4 12s.

I would like around 4.5 cubes net tuned to 32 hertz.

 

When designing it, the only way to get a port velocity below 22(forgot the units) is by having a 7" wide slot port which gives me 95"2 of port.  

 

can anyone help me out with my design please.  I may be completely overlooking something.  I am open to suggestions on any aspect of the build.

 

ALSO:

 

I have an enclosure for 2 12s.  They were JL w3v3 12s.  I built the enclosure exactly as the  JL tech designed it for me.  It is 3.5 cubes net tuned to 32 hertz.  My main concern with using those is it is at the minimum size requirement per FI which is 1.8-2.5 cube per sub.  My next concern is port area which is 2" wide, 12.5 tall, and 13.5 deep(into sub enclosure).  I feel like such a small port area wont be adequate port velocity wise.  Do you think its worth even putting them in my current enclosure, or just building one a little more suited to these subs.

 

Thank you for any help.

 

Look to build a 4.5 cubic feet net enclosure with 60 square inches of port area tuned to 32Hz.

 

Pretty big enclosure make sure it fits before building.

 

[MDdrolman]

Thank you REVO, that answer was a big help and really cleared up some confusion I was having.