home theater subwoofer advice?

Reducing the enclosure volume raises the system Q. If the compliance of the driver is not made for a sealed enclosure, you will have further problems, and the driver will not have as low an Fs.(system frequency), or roll off slope. It is most unlikely you will ever reproduce or require a musical peak of any significant duration that will need 1500 watts. 1500 watts @2 Ohms = 750 Watts @ 4 Ohms = 325 Watts @ 8 Ohms (approx) Home amplifiers are 8 ohm, not 2 Ohm, and are rated at that load. That sort of stat is good for salesmen, but meaningless in audio terms. It is possible to "add" an apparent 30% to the effective volume of a cabinet by stuffing (filling) the cabinet volume with loose fiberfill. Ducted cabinets are usually LARGER, not smaller, than sealed enclosures, for any given driver, and duct length. Port tuning is also affected, and expect particular stated cabinet volumes.oftentimes just to fit into the box. Car audio speakers are the worst choice for home audio, and have magnet structures optimized for road vibration, etc, Halving a sealed enclosure volume doubles the back pressure on the cone, sort of like pressing on it with your hand would. You might end not hearing the speaker at all.

As noted elsewhere, the Ohm load of the driver must be brought into the range expected by the amp used, usually 6-8 ohms either with electronic components or coupling appropriately with other voice coils. Speaker engineering is, eh, engineering, not changing a tire. Quoted MFG specs are only good for the conditions and connections they state and expect, and are not always accurate.. Changes in the conditions or connections yield vast changes to the specs values and require formulae computation and test to recompute. See a good DIY site with appropriate calculators and explanations. You might be able to use the driver in a small band pass 2nd or third order enclosure, but again, that would require using the required calculative processes, and in the end, significant woodworking skills.and electronic modifications to the driver element connections. IF the driver has a recommended closed box volume, it might be smaller than the ported design recommended, and might be reduced 30 % further by stuffing it, without raising its floor frequency so high as to make it worthless as a bass driver. An internal cabinet volume of 14 x 11 x 26, stuffed with loose fiberglass might give you a workable approximation of a 3 cu ft cabinet volume.

It probably will work but as others have said that driver will work best with the proper enclosure size:

https://www.skaraudio.com/products/zvx-12v2-12-inc...

If you are using this at home I'm sure you have room for the proper enclosure.

To do it correctly you will need a really good 12v amp and a very large 12v power supply. By the time you are done with all that you might as well just purchased a good home theater woofer. Otherwise the box is a little small, but if that's all the space you have I suppose you would switch it out later. The box size will be the least of your challenges.

Don't use a car subwoofer for a home theater system.

Theoretically it might be possible to do by adding some resistors and capacitors and sound absorption and proper innovative venting inside the box......Its usually better for an amateur to build a larger box than required not a smaller box but with the right equipment for testing and expertise knowledge, it might be possible to do at least theoretically anyway

[1] No. It needs to be mounted in the recommended size ported enclosure or it will not perform to specs or sound good. It was designed for a 3 cubic foot enclosure with a specific port size.

[2] Be aware that using a car audio subwoofer in a home theater system requires recalculating the power handling ability based on 110 volts AC vs 12 volts DC and that most home amplifiers cannot handle a speaker having 2 ohms impedance and many cannot even handle a 4 ohm load. Unless that sub has dual 4 ohm voice coils that can be wired in series for 8 ohms I'd use a different sub designed for home theater use