This isn't simple. It takes more than just a box. The speaker has to be right for the box and there are many different speakers to adapt to the box and it's configuration. Reflex systems typically require largest boxes. Sealed boxes often can be much smaller, but compliant speakers for sealed systems are made just for that application (Acoustic suspension). The best performance I ever saw was a JBL "Voice of the Theater" cabinet with two 15" woofers per cabinet a 10" midrange and matched tweeter, triamped with a MacIntosh 90 watt tube amp (bass), a 45 watt MacIntosh tube amp (midrange) and a 25 watt MacIntosh tube amp (tweeter with acoustic lense). That set up produced a sound exactly like a live performance. That will never fit in a car and tube amps should not either be used in a car- besides that the KT88, 12AX7 and 12AT7 tubes throw off enough heat to cook a magpie, and cars don't have a power supply to run them. Take a look in this site for info on sub cabinets: Subwoofer Enclosure Calculators, Parallel, Series, Port Length and Volume

 

Thank you for the response. I already have the equipment ready to go, I was mostly interested to see if anyone had built a box and how they approached it.

I am debating on glassing it in vs a standard MDF box setup. I will CNC the internals to specific airflow design to allow for less cavitation on the ports using simulation software from Fusion360. but that dang rear seat and the tray keeps me returning to drawing board.

The 3rd row makes for a logistical issue and building the right airspace to the subs to perform at the frequency response I am looking for. Since the seats slide and lay, I have to decide on function and frequency vs form to accommodate the 3rd row.

Or do I start from scratch, build a musically accurate sealed enclosure and entertain the thought of running a Utopia and an FDP1.2

 

Figure it out yet?

 

Who has the wiring diagram to tap off the rear OEM subwoofer signal for my aftermarket amp on my sub box? I need to know where I can find the wires to the positive / negative leads feeding the OEM subwoofer on the drivers rear panel. (2024 Platinum) Vehicle is so new, Crutchfield does not have any info. yet. I have a JL Audio 500 watt mono amp and a JL audio 12" sub / box that fits nicely behind the 3rd row. It will def. thump if I can find the high powered leads.

 

Go to a public library and see if the diagram is included in a Chilton's, Motors, Clymer's or even the Owner's manual for that model, if they have that in their collection. If no joy, ask the librarian to show you a Sam's Photofact for your sound system. Photofacts include schematics and pictoral diagrams. You might even need to use a library that is also a "depositary" library- usually the main library in your town. Depositary libraries must collect every published material.