FBT X-Sub 118SA Active Subwoofer

FBT X-SUB 118SA Active Subwoofer — Low-Frequency Extension for X-LITE and X-PRO Systems

Active subwoofers must deliver impactful bass while maintaining balance with the entire signal chain. The FBT X-SUB 118SA covers 38 Hz to 120 Hz at 136 dB SPL, using an 18-inch bass-reflex cabinet and a 1200W Class D amplifier. Relying on 18 mm birch plywood and four DSP presets, this model integrates effortlessly into X-LITE and X-PRO systems for live events, permanent installations, or mobile PA rigs.

Onboard DSP and Birch Plywood Enclosure

System-specific tuning is possible via four DSP presets, each pairing two frequency responses with two cutoff frequencies—no need for external processors. Unlike typical MDF or plastic enclosures, the birch plywood cabinet with a scratch-resistant finish helps control internal resonance.

Woofer, Frequency Range, and Output Level

Subwoofer choice is about matching frequency reach and output for your space.

• Woofer: 18-inch with 3-inch voice coil — this high-excursion driver moves air efficiently for physical bass impact
• Frequency Response: 38 Hz – 120 Hz (−6 dB) — delivers deep sub-bass with smooth mid-bass transition
• With 136 dB half-space SPL, this sub handles demanding venues without distortion or compression issues.

Class D Amplification and Stereo Signal Path

Integrated amplification eliminates the hassle of an external sub amp. The stereo signal path means you retain channel separation throughout your system.

• Built-in Amplifier: 1200W Class D — benefits from efficient switching technology and produces low heat
• Input Connectors: stereo XLR/Jack combo with loop-through — compatible with balanced and unbalanced signals
• High-Pass Outputs: stereo XLR with HP filter — routes filtered signals to satellites, avoiding the need for an external crossover
• Switch the phase (0°/180°) to align the subwoofer’s polarity with satellites for optimal bass summation.

Birch Construction and Stage-Friendly Design

Smart physical design ensures the subwoofer fits into stage setups and withstands frequent load-ins.

• Dimensions (W×H×D): 510 × 655 × 630 mm — compact enough to position beside drum risers and monitors
• The manageable 39.8 kg weight allows for straightforward two-person handling.
• Top Mount: M20 threaded socket — use for mounting a standard satellite pole
• Pre-drilled positions enable quick installation of optional 100 mm wheels, speeding up transport between venues.