Product Launch - Q Acoustics QB12 - 12" Active Subwoofer

Product Launch - Q Acoustics QB12 - 12" Active Subwoofer

We've been waiting for the launch of a larger Q Acoustics Subwoofer for some time, first hearing about one being in the pipeline 2 years ago. It's the missing piece to the 3000i Series of speakers to take the package to the next level.


What Hi-Fi have already been given one for a review and it certainly has come in glowing, giving it a 5 star award accros the board.

"As long as you have the space, budget and amiable enough neighbours, we say go for it. Just be prepared to host movie nights from now on."

Cabinet Design & Engineering Introduction

  • Dart bracing - Internal bracing provides additional cabinet rigidity and suppresses cabinet resonance.
    • The ‘dart brace’ provides high axial stiffness directly to the motor system, effectively providing a mechanical ground to the drive unit. The load is spread to all faces of the cabinet which also rigidly constrains the enclosure walls effectively over the subwoofer’s operating bandwidth. The ‘dart brace’ not only gives superior mechanical stability to the drive unit over unbraced systems, that can otherwise result in drive unit ‘bounce’ on the mounting fixtures and baffle, but also reduces the ‘ballooning’ effect of the cabinet, critical for subwoofers that inherently contain high internal acoustic pressure.
  • A reinforced MDF cabinet with a 36mm thick baffle.
  • Custom die-cast aluminium heat sink on rear panel supports and cools the ultra-low distortion power amplifier and power supply.
  • Recessed and hidden rear terminal panel, hides all plugs and channels cables neatly out through the base of the subwoofer.
  • Custom designed adjustable spiked feet give firm support on carpeted floor.
  • Reinforced rubber caps supplied for use with wooden floors.


Long-throw 12” driver delivers high sensitivity and excellent dynamics. • High Bl motor. • High stiffness paper cone with straight sides. • Large 50mm voice coil diameter to reduce thermal compression.

Amplifier & Electronics

Ultra-low distortion 220W Class D power amplifier capable of delivering 17A peak current.

Active limiter prevents unpleasant distortion when amplifier over-driven • Texas Instruments TPA3255 Class D Power Amplifier features an advanced integrated feedback design with proprietary high-speed gate driver error correction (PurePath™ Ultra-HD) delivering ultra-low distortion across the audio band.

Analogue active filters with Linkwitz-Riley pole-zero shifting result in flat acoustic frequency and linear phase response.

0°/180° phase switch to optimise integration with left and right speakers.

Auto switch-on from standby in the presence of an audio input. Can be overridden to force unit on continuously.



Enclosure Type
Infinite Baffle (sealed)
Enclosure Material

Drive Units

12” (305mm) High-Excursion
Output Power
200 W Class-D (controlled by limiter)
Max Output Power  
220 W (@1% amplifier THD)
Frequency Range
28Hz - 300Hz
Overall Dimensions

400 x 400 x 446mm

(H x W x D) without spikes

18.5 kg
Input Impedance
13 kΩ

Input Sensitivity

(For full power at 50Hz, level set to maximum)


150 mV, (L=R)

300mV, (L only)

Input Sensitivity For Auto Switch-On

1.5 mV (L=R)

3 mV (L only)

Crossover Frequency  
70 Hz - 225 Hz (12dB/octave)