Stealth Acoustics 255R


Brand Stealth Acoustics

The Stealth Acoustics 255R is an integrated monaural subwoofer amplifier / crossover system designed as a low distortion power source for Stealth Acoustics wall or ceiling mounted, invisible subwoofer panels or other un-powered subwoofer speakers. Intended for whole house audio or home theater bass applications, the 255R may stack with other components or mount in a standard 19” equipment rack requiring only two RU spaces (3-1/2”). Removable rack mount ears are provided. The 255R delivers a solid 250 watts into an 8Ω load and 350 watts into 4Ω. A variable low pass, 18db per octave filter allows for infinite crossover points from 50Hz to 100Hz.

With a full complement of input and output connectors, the 255R is easily integrated into any audio system. Inputs include RCA line level, balanced XLR line level, and 5-way binding post speaker level, all with pass-through capability. The speaker level input/pass-through connections allow the 255R to feed directly from full-range speaker lines, anywhere in the system. The 255R’s amplifier output connection is via a 5-way binding post designed to accept heavy guage speaker wires. A selectable automatic turn-on feature activates the amplifier only when audio signals are present.

Other features include an internal, quiet, 8-stage cooling fan that automatically engages as required. Front panel controls include volume control, variable low pass filter, low pass filter on/off switch, phase control, power switch and six power output monitor LED’s.

Features and Functions


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” or “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



Mono Power Output

250 watts @ 8 < 0.05 THD

350 watts @ 4 < 0.05 THD

Total Harmonic Distortion

<0.05 @ 1 watt 4 / 100Hz

Signal to Noise Ratio

86 dB below rated output

Crossover Section

Low Pass Filter: 50Hz – 150Hz / 18 dB per octave (variable with bypass switch)

High Pass Filter: 18Hz / 30 dB per octave (fixed)

System Impedance

8Ω nominal – 4Ω minimum

Current Draw

6.2A @ 350W/4 – 115VAC/60Hz


Width: 19” (482 mm)

Height: 3-1/2” (89 mm) – without feet

Depth: 13-5/8” (346 mm)


Black anodized aluminum

Product Weight

31.3 Lbs. (14.20 kg)

Shipping Weight

32.5 Lbs. (14.74 kg)

Included Accessories

Removable power cord

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