I had a box designed by chris at fishercustoms, and here is what he came up with:

The total Net volume came out to be 1.8cu ft exactly, a 1.74" x 14" port tuned to 33hz, 13.53 sq in of port per cu ft, and I have a couple questions:

1. Is that too small for a 12" Fi Q? They do recommend a minimum of 1.8, but i'm worried this box won't make it sound good because the net volume is too small.

2. What happens if the box is too small?

3. Whats the difference between having a larger box versus a smaller box? Like having a 2.2 versus 1.8? Most of the videos I see online of this sub have a box larger than 2.2 cu ft, and their car is basically falling apart.

Any help would be great. I want to know this box will sound good for a 12" Fi Q before I tell someone to build it for me

Should work fine. Smaller just pushes the enclosures resonance up a little higher. With 1.8 cuft tuned to 33Hz, it will push the peak up closer to 39Hz. In car with the vehicles transfer function it will still perform great down to 30Hz (where you should have the subsonic set). If you went up to 2.2 cuft your same tuning, it would be at about 26Hz for the peak. Slightly higher (about .5 dB) efficiency as well.

All in all it should perform fine for a solid daily driving setup.

Thanks,

Scott