Sky High Car Audio FE Slim Subwoofer Series

Shop Sky High Car Audio FE Slim Series shallow-mount subwoofers in 8-inch, 10-inch and 12-inch sizes. The FE Slim Series is designed for customers who want real daily-driver bass but do not have enough room for a traditional full-depth subwoofer and large enclosure.

These compact subwoofers are a strong option for standard-cab trucks, behind-seat boxes, under-seat enclosures, small trunks, compact SUVs, stealth installations and other space-limited car audio systems.

Each FE Slim model is available with dual 2-ohm or dual 4-ohm voice coils. Choose the correct voice-coil configuration based on the number of subwoofers, the final impedance required by the amplifier and how the voice coils will be wired.

Shop Sky High FE Slim Subwoofers

Sky High FE-8SL 8-Inch Shallow Subwoofer

The Sky High Car Audio FE-8SL 8-inch shallow subwoofer is rated for 200 watts RMS and is available with dual 2-ohm or dual 4-ohm voice coils.

The compact 8-inch design can work well for:

  • Small sealed or ported enclosures
  • Under-seat bass systems
  • Behind-seat truck boxes
  • Compact cars with limited trunk space
  • Stealth installations
  • Multiple-subwoofer builds with limited mounting space

The FE-8SL is the smallest subwoofer in the FE Slim lineup and can provide useful low-frequency output where a conventional 10-inch or 12-inch subwoofer is not practical.

Sky High FE-10SL 10-Inch Shallow Subwoofer

The Sky High Car Audio FE-10SL 10-inch shallow subwoofer is rated for 250 watts RMS and is available with dual 2-ohm or dual 4-ohm voice coils.

The 10-inch FE Slim offers a strong balance between compact enclosure requirements and usable daily bass. It can make sense for:

  • Standard-cab and extended-cab trucks
  • Compact trunk installations
  • Behind-seat enclosures
  • Under-seat boxes with enough mounting area
  • Customers who want more cone area than an 8-inch subwoofer
  • Daily systems using moderate amplifier power

A 10-inch shallow subwoofer can provide more bass presence than a smaller 8-inch model while remaining easier to fit than many conventional-depth 12-inch subwoofers.

Sky High FE-12SL 12-Inch Shallow Subwoofer

The Sky High Car Audio FE-12SL 12-inch shallow subwoofer is rated for 300 watts RMS and is available with dual 2-ohm or dual 4-ohm voice coils.

The 12-inch FE Slim is the largest model in this collection and is a strong direction for customers who have enough enclosure area for a 12-inch subwoofer but cannot accommodate a traditional deep motor structure.

The FE-12SL can work well for:

  • Truck enclosures with limited depth
  • Slim trunk boxes
  • Compact SUVs where cargo space must remain usable
  • Single-subwoofer daily systems
  • Customers wanting more cone area from a shallow design
  • Stealth builds that still need noticeable low-frequency output

Choosing Between 8-Inch, 10-Inch and 12-Inch FE Slim Subwoofers

The largest subwoofer is not automatically the best choice. Start with the actual space available for the enclosure, then choose the model that fits the vehicle, amplifier and bass goal.

Choose the 8-Inch FE Slim When:

  • Available enclosure space is extremely limited.
  • The installation must fit under or behind a seat.
  • You want a compact and responsive daily bass system.
  • You plan to use multiple small subwoofers.
  • An enclosure for a 10-inch or 12-inch model will not fit correctly.

Choose the 10-Inch FE Slim When:

  • You want a balance between bass output and manageable enclosure size.
  • The vehicle has enough room for more cone area than an 8-inch model.
  • You are building a compact truck or trunk system.
  • You want useful daily bass without giving up excessive cargo space.

Choose the 12-Inch FE Slim When:

  • You have enough mounting area for a 12-inch subwoofer.
  • You want the largest cone area available in the FE Slim lineup.
  • The enclosure must remain shallow but can be wider or taller.
  • You want stronger low-frequency presence from a single subwoofer.
  • You are building a truck, SUV or compact trunk system around a shallow box.

Shallow Subwoofers Still Need the Correct Enclosure

A shallow-mount subwoofer saves mounting depth, but it does not eliminate the need for a properly designed enclosure. The box must still provide the correct internal air space, sufficient strength, safe cone clearance and the appropriate sealed or ported design for the exact subwoofer.

Before building or ordering an enclosure, confirm:

  • Recommended net enclosure volume
  • Sealed or ported enclosure requirements
  • Subwoofer mounting depth
  • Cutout diameter
  • Overall frame diameter
  • Magnet clearance
  • Cone and surround clearance
  • Terminal and speaker-wire clearance
  • Port displacement and subwoofer displacement
  • Available space inside the vehicle

Do not build the enclosure around the advertised speaker diameter alone. Measure the vehicle and review the specifications for the exact FE Slim model before cutting the box or mounting panel.

Dual 2-Ohm vs Dual 4-Ohm FE Slim Subwoofers

The dual 2-ohm and dual 4-ohm versions are not different power levels. The voice-coil choice determines the wiring options available and the final impedance the amplifier will see.

For one FE Slim subwoofer:

  • A dual 2-ohm model can normally be wired to a 1-ohm or 4-ohm final load.
  • A dual 4-ohm model can normally be wired to a 2-ohm or 8-ohm final load.

Multiple subwoofers create additional wiring possibilities. Choose the voice-coil configuration before purchasing the amplifier so the completed system produces a safe final load that the amplifier can support.

Matching an Amplifier to FE Slim Subwoofers

Match the amplifier to the combined RMS rating and final impedance of the subwoofer system. Do not choose an amplifier based only on its largest advertised wattage number.

Before selecting an amplifier, confirm:

  • The RMS rating of each FE Slim subwoofer
  • The selected dual 2-ohm or dual 4-ohm configuration
  • The number of subwoofers being installed
  • How the voice coils and subwoofers will be wired
  • The final impedance presented to the amplifier
  • The amplifier’s rated RMS output at that impedance
  • The amplifier’s minimum stable impedance
  • The power wire, ground wire and fuse protection required by the amplifier

Browse available monoblock car audio amplifiers when planning power for an FE Slim subwoofer system.

Set Gain and Crossovers Correctly

Correct gain and crossover settings are important even with a moderate-power subwoofer system. Amplifier gain should be used to match the amplifier input sensitivity to the radio, line-output converter or DSP signal. It is not an additional volume control.

An improperly set gain can create clipping, distortion, excessive heat and subwoofer damage. The low-pass crossover and subsonic filter should also be set around the enclosure design, tuning frequency and intended operating range of the subwoofer.

Shop All Sky High Car Audio Subwoofers

Compare the FE Slim Series with standard-depth FE, FXB, BMX, FMX and FXXL models in the Sky High Car Audio subwoofer collection.

Helpful Subwoofer and Bass-System Guides

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