FBT Subline 115 SA Active Subwoofer

FBT Subline 115 SA — Compact 15" Active Subwoofer for Live Sound

Built in Italy, the FBT Subline 115 SA is a processed active subwoofer engineered to extend low-frequency response across the FBT speaker family. A 700 W RMS Class D amplifier drives a 15" high-excursion woofer in a bass-reflex cabinet, producing 135 dB SPL from a 28 kg box aimed at FOH engineers, mobile DJs, and rental companies.

What Sets This Sub Apart

What separates the Subline 115 SA from generic 15" powered subs is the FBT-engineered DSP and the Baltic birch cabinet. The onboard processor ships with eight presets, two EQ curves, two LPF crossover settings, and a cardioid configuration that lets a pair of subs reject rear-stage energy without external processing. A Neutrik TRUE1 locking power inlet and through-output eliminates the need for a mains switch.

Amplification and Output

Delivering 700 W RMS to the LF driver and pushing 135 dB peak SPL, the built-in amplifier provides enough headroom for a 2.1 or 2.2 stack covering up to roughly 300 people.

• Amplifier: Class D, switch-mode power supply
• RMS Power: 700 W
• Peak SPL: 135 dB

Driver and Cabinet

At the center of the cabinet sits a 15" high-excursion magnet woofer with a 75 mm voice coil in a bass-reflex enclosure tuned for punch and depth. The enclosure is built from 15 mm Baltic birch plywood with internal bracing.

• LF Driver: 15" (380 mm) high-excursion woofer
• Voice Coil: 75 mm (3")
• Frequency Response: 40 Hz – 140 Hz
• Cabinet: 15 mm (0.59") Baltic birch plywood, bass-reflex

DSP, Connectivity, and Setup

On the rear panel, stereo XLR inputs and through-outputs sit alongside an 8-step delay from 0.25 m to 3.5 m, a 0°–180° phase switch, and three status LEDs. An M20 threaded pole socket on top accepts standard satellite speaker poles.

• DSP: 8 presets, 2 EQ, 2 LPF crossover, cardioid configuration
• Delay: 8 steps, 0.25 m – 3.5 m
• I/O: Stereo XLR in/out
• Power: Neutrik TRUE1 in/out
• Pole Mount: M20 (20 mm) top socket
• Dimensions: 500 × 517 × 570 mm
• Weight: 28 kg