Sky High Car Audio FXXL Subwoofer Series

Shop Sky High Car Audio FXXL Series subwoofers for extreme demo systems, competition-style builds, large ported enclosures, walls, blow-through installations and high-output daily vehicles. The full-size FXXL lineup includes 12-inch, 15-inch and 18-inch ferrite subwoofers rated for 5,000 watts RMS.

This collection also includes the working 3.5-inch FXXL Neo Mini and Ferrite Mini subwoofers. These compact models bring the recognizable FXXL styling into custom mini enclosures, desktop audio projects, RC builds, showroom displays and other creative installations.

The full-size 12-inch, 15-inch and 18-inch FXXL subwoofers are available in dual 1-ohm and dual 2-ohm configurations. Choose the correct voice-coil option around the number of subwoofers, amplifier stability and final impedance planned for the system.

Shop Sky High FXXL Subwoofers

Sky High FXXL 12-Inch Subwoofer

The Sky High Car Audio FXXL Series 12-inch subwoofer is rated for 5,000 watts RMS and is available with dual 1-ohm or dual 2-ohm voice coils.

The FXXL 12-inch uses a 4-inch, 8-layer high-temperature voice coil and a large quad-stack ferrite motor. It gives serious builders a way to use the FXXL platform in a more manageable diameter than the 15-inch or 18-inch models.

The FXXL 12-inch can work well for:

  • Extreme single 12-inch builds
  • Dual and multiple 12-inch systems
  • High-output trunk installations
  • Demo and competition-style vehicles
  • Large ported or bandpass enclosures
  • Builders wanting serious power handling in a 12-inch format

Sky High FXXL 15-Inch Subwoofer

The Sky High Car Audio FXXL Series 15-inch subwoofer is rated for 5,000 watts RMS and is available with dual 1-ohm or dual 2-ohm voice coils.

Its 4-inch, 8-layer high-temperature voice coil and large quad-stack ferrite motor are designed for builders using serious amplifier power, heavy electrical support and enclosures built around extreme output.

The FXXL 15-inch can be a strong direction for:

  • Large trunk and hatchback systems
  • Single or multiple 15-inch installations
  • Blow-through bass builds
  • Wall and no-wall systems
  • Demo vehicles
  • Competition-style projects
  • Large ported, fourth-order and sixth-order enclosures

Sky High FXXL 18-Inch Subwoofer

The Sky High Car Audio FXXL Series 18-inch subwoofer is rated for 5,000 watts RMS and is available with dual 1-ohm or dual 2-ohm voice coils.

The FXXL 18-inch provides the largest cone area in the full-size FXXL lineup. It is intended for substantial enclosures and systems with the amplifier power, wiring, battery capacity and alternator output needed to support extreme bass demand.

The FXXL 18-inch is best considered for:

  • Large SUV and van builds
  • Full wall and no-wall systems
  • Single or multiple 18-inch installations
  • Large blow-through enclosures
  • Extreme demo vehicles
  • Competition-style bass systems
  • Builders designing the entire vehicle around the subwoofer stage

Do not force an 18-inch subwoofer into an enclosure that is too small simply because the basket fits. The box must provide the required net air space, port area, bracing, cone clearance and vehicle loading needed by the subwoofer.

Sky High FXXL 3.5-Inch Mini Subwoofers

The FXXL Mini models are real working 3.5-inch subwoofers, but they serve a completely different purpose than the full-size 5,000-watt RMS FXXL models. They are intended for compact and creative audio projects rather than extreme full-size vehicle bass systems.

FXXL 3.5-Inch Neo Mini Subwoofer

The Sky High Car Audio FXXL 3.5-inch Neo Mini subwoofer uses a compact neo motor structure, forged carbon-fiber-style dust cap and all-black FXXL styling.

The Neo Mini can be used for:

  • Custom mini enclosures
  • RC audio projects
  • Desktop audio systems
  • Compact demonstration setups
  • Retail showroom displays
  • Creative builds where a conventional subwoofer will not fit
  • Sky High Car Audio collections and display systems

FXXL 3.5-Inch Ferrite Mini Subwoofer

The Sky High Car Audio FXXL 3.5-inch Ferrite Mini subwoofer uses a compact ferrite motor while retaining the forged carbon-fiber-style dust cap and stealth appearance of the larger FXXL lineup.

The Ferrite Mini is a fun option for:

  • Custom display enclosures
  • RC and scale audio projects
  • Desktop audio builds
  • Retail counter displays
  • Compact custom installations
  • Conversation-starting audio projects

Choosing Between the FXXL 12, 15 and 18-Inch Models

The largest subwoofer is not automatically the correct subwoofer. The available enclosure space, intended output, amplifier power, vehicle design and electrical support must all be considered.

Choose the FXXL 12-Inch When:

  • You want full FXXL power handling in the smallest full-size option.
  • A 15-inch or 18-inch enclosure will not fit correctly.
  • You are planning a serious trunk or compact demo build.
  • You want to use multiple subwoofers while controlling total enclosure size.

Choose the FXXL 15-Inch When:

  • You want increased cone area without moving to an 18-inch design.
  • You have room for a large ported or bandpass enclosure.
  • You are building a hatchback, SUV, blow-through or wall system.
  • Deep bass and extreme output are both priorities.

Choose the FXXL 18-Inch When:

  • You want the greatest cone area available in the FXXL lineup.
  • The vehicle has substantial enclosure space.
  • You are building a wall, no-wall, large SUV or van system.
  • The entire electrical and amplifier system is being designed around extreme bass output.

Dual 1-Ohm vs Dual 2-Ohm FXXL Subwoofers

The D1 and D2 versions are not different power levels. The voice-coil configuration determines the final impedance options available to the amplifier.

For one full-size dual-voice-coil FXXL subwoofer:

  • A dual 1-ohm model can normally be wired to a 0.5-ohm or 2-ohm final load.
  • A dual 2-ohm model can normally be wired to a 1-ohm or 4-ohm final load.

Using multiple subwoofers creates additional final-load possibilities. Decide how many subwoofers will be installed, how they will be wired and what minimum impedance the amplifier can safely support before choosing D1 or D2.

Never connect an amplifier below its rated minimum impedance. An unsafe load can increase heat and current demand while causing protect mode, blown fuses or amplifier failure.

Match the Amplifier to the Complete FXXL System

A full-size FXXL build should be planned as a complete system rather than a simple subwoofer replacement. The subwoofer, amplifier, enclosure, final impedance, wiring, fuse protection, batteries, alternators and tuning must all work together.

Before choosing the amplifier, confirm:

  • The number of FXXL subwoofers
  • The selected dual 1-ohm or dual 2-ohm configuration
  • The completed final impedance
  • The amplifier’s RMS output at that impedance
  • The amplifier’s minimum stable impedance
  • The required power and ground wire size
  • The required fuse protection
  • The battery capacity needed by the amplifier
  • The alternator output available while the vehicle is running

Browse monoblock car audio amplifiers when planning power for a full-size FXXL subwoofer system.

The Enclosure Is Critical

A 5,000-watt RMS subwoofer cannot perform correctly in a weak, undersized or poorly designed enclosure. The box affects output, low-frequency extension, cone control, mechanical stress and how the system loads inside the vehicle.

Before building the enclosure, verify:

  • Recommended net internal volume
  • Suitable ported or bandpass design
  • Recommended tuning frequency
  • Required port area and port length
  • Subwoofer displacement
  • Port and bracing displacement
  • Mounting depth and cutout diameter
  • Cone and surround clearance
  • Enclosure material and bracing requirements
  • Available loading space inside the vehicle

Browse car audio subwoofer boxes and enclosures when planning the enclosure portion of the system.

Electrical Support for Full-Size FXXL Builds

Full-size FXXL systems require more than a large amplifier. They need properly sized power and ground wiring, secure connections, correct fuse protection, adequate battery capacity and enough alternator output to maintain stable voltage.

Browse Sky High Car Audio amplifier wiring kits and Sky High Car Audio Big 3 kits when planning the wiring and charging paths for the system.

A Big 3 upgrade strengthens important charging and grounding connections, but it does not increase the alternator’s rated output. Extreme FXXL builds may require upgraded batteries, high-output alternators or multiple-alternator charging systems depending on the total amplifier demand.

Shop All Sky High Car Audio Subwoofers

Compare the FXXL Series with FE Slim, FE, FXB, BMX and FMX options in the complete Sky High Car Audio subwoofer collection.

Helpful FXXL and Bass-System Guides

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