Vehicle: 2006 Ford F-150 SuperCrew
Location in the vehicle: Underneath the long side of the rear 80/20 split bench seat
Space available (Length x Width x Height): 33" x 12" x 4.5/6.5 (Wedge)
Subwoofer make and model: JL Audio 10W0v3-4
Subwoofer Size: 10"
Number of Subwoofers: 1
Type of Port (Kerfed, Slot, Aero, etc.): N/A (Sealed)
What type of music do you like?: Country (Tight Punch) and Rap (Deep & Long)
Is your goal SPL or Everyday Music?: Music Quality
Tuning Freq (Hz): ?
Volume: 0.65 cu ft / 18.41 L (Internal Net)

Additional info from their website:
Free Air Resonance (Fs): 32.09 Hz
Electrical “Q” (Qes): 0.64
Mechanical “Q” (Qms): 10.752
Total Speaker “Q” (Qts): 0.604
Equivalent Compliance (Vas): 1.095 cu ft / 31.01 L
One-Way Linear Excursion (Xmax)*: 0.45 in / 11.4 mm
Reference Efficiency (no): 0.15%
Efficiency (1 W / 1 m)**: 84.07 dB SPL
Effective Piston Area (Sd): 48.909 sq in / 0.0316 sq m
DC Resistance (Re): 4.280 Ω
* Xmax specifications are derived via one-way voice coil overhang method with no correction factors applied.
** Efficiency (1 W / 1 m) is not an accurate indicator of a subwoofer’s output capability and should not be used as a comparison to other subwoofers to determine which one is “louder”.

Sealed enclosure specifics from their website:
Wall Thickness: 0.75 in / 19 mm
Front Baffle Thickness: 0.75 in / 19 mm
Volume (net int.): 0.65 cu ft / 18.41 L
External Width (W): 18 in / 457 mm
External Height (H): 11 in / 279 mm
External Depth (D): 9 in / 229 mm
F3: 42.4 Hz
Fc: 53.23 Hz
Qtc: 1.002
* The enclosure recommendations listed above are external dimensions which assume the use of 0.75 in (19 mm) thick material. If you are using 0.625 in (16 mm) thick material, subtract 0.25 in (6.5 mm) from each dimension. Do not use any material with a thickness of less than 0.625 in (16 mm) as this may compromise the rigidity of the enclosure.
* All enclosure volumes listed above are net internal volumes! Driver displacement, port displacement and brace displacement must be added to obtain the final gross internal volume. All enclosure dimensions above have already taken this into account.
* When using multiple subwoofers in a common enclosure you will need to recalculate the enclosure and port dimensions. For assistance please contact your authorized JL Audio dealer or JL Audio Technical Support.
* We recommend the use of this speaker in a bi-amplified system using high-quality satellite speakers and a high-quality amplifier. We do not recommend the use of this subwoofer with a passive crossover (coil), as this type of device will adversely affect performance.

1. Is the volume listed as 0.65 cu. ft. the minimum, and if so then is there a maximum?
2. Since the enclosure that I'm going to build will be quite irregular in shape, can I use a calculator somewhere to figure out if it will have enough inner air space?
3. When assembling the box, what is the best method to secure the edges together (in addition to glue obviously)?
4. Which frequencies listed above might affect my enclosure, and how?

Thank you for your help and wisdom!