Stealth Acoustics Monural Subwoofer Amplifier SA255 MKII

The Stealth Acoustics SA255 MKII is an integrated monaural subwoofer amplifier/crossover system designed as a low distortion power source for Stealth Acoustics invisible subwoofer panels or other un-powered subwoofers.  The SA255 MKII can also be used for full range speakers when the low pass filter is off.

  • Rack mountable
  • Variable low pass filter
  • Auto On/Standby function
  • Balanced line input and output
  • DC protected fixed high pass filter
  • 12v trigger function
  • Output monitor LEDs


Rack Mountable

(2) RU spaces: 3-1/2” (89 mm)
(*Provided rack ears are removed)

DC Protected

Fixed high pass filter @ 18Hz

Variable Low Pass Filter

50 to 150Hz / 18 dB per octave

Power Standby LED

Red (blue when system is active)


Auto On/Standby Function

Switch selectable on/off

Flexible Inputs with Pass Through

Binding post speaker level inputs / outputs
RCA line level inputs / outputs
XLR balanced line inputs / outputs

Amplifier Output Connector

5-way binding post


Output monitor LED’s

6 level readings

Phase Switch

Low Pass Filter on/off Switch

Fan Cooled

Automatic – 8 speed stages

110v and 220v Input Voltages

TypeMonaural Subwoofer Amplifier/Crossover
Mono Power Output250 watts @ 8 < 0.05 THD_x000D_
350 watts @ 4 < 0.05 THD
Total Harmonic Distortion<0.05 @ 1 watt 4 / 100Hz
Signal to Noise Ratio86 dB below rated output
Low Pass Filter50Hz – 150Hz / 18 dB per octave
High Pass Filter18Hz / 30 dB per octave (fixed)
System Impedance8Ω nominal, 4Ω minimum
Current Draw6.2A @ 350W/4 – 115VAC/60Hz
Width19” (482 mm) with ears
Height3-1/2” (89 mm) without feet
Depth13-5/8” (345 mm) without knobs
Weight31.3 Lbs. (14.20 kg)