Active Subwoofer, 12-inch with DSP | Q Acoustics Q SUB120

Product Overview

The Q Acoustics Q SUB120 is the largest model in Q Acoustics’ Q SUB range, built for bigger rooms and full surround-sound home cinema systems that need genuine infra-bass low-frequency effects — the kind you feel as much as hear. Its 12″ driver and sealed, infinite-baffle cabinet make it the flagship option above the 10″ Q SUB100 and 8″ Q SUB80.

A custom-designed amplifier module built by Q Acoustics combines digital signal processing (DSP), the power amplifier, and the power supply into a single unit. It uses four digital amplifier stages in a parallel bridge-tied load (PBTL) configuration, a design chosen to improve efficiency, reduce output impedance, and give tighter control over the driver, while keeping heat dissipation low. This design delivers up to 300W of continuous power and 600W peak, with total harmonic distortion held below 0.1% at rated power.

Onboard DSP handles more than basic amplification: dual phase and delay controls allow fine-tuning of signal alignment with the main speakers for a given room, and the system automatically detects whether the incoming signal is stereo or mono and adjusts gain accordingly. An adjustable low-pass filter, tunable from 40Hz to 250Hz, allows the Q SUB120 to be matched to the upper frequency roll-off of almost any partnering speaker system, whether stepping in for a stereo setup or anchoring a full 5.1/7.2 home cinema system.

The drive unit uses a heavy-duty steel chassis, paper cone, and rubber surround, with a larger 50mm voice coil and an aluminium demodulation ring to reduce inductance-related distortion. The sealed (infinite baffle) cabinet is built from 18mm high-density MDF with a 36mm double-thickness front baffle and internal dart bracing for rigidity, and — because there’s no bass port — the design allows for easier placement near walls and furniture without the port-related placement compromises of a reflex-loaded subwoofer.

Key Features

• 12″ driver in a sealed (infinite baffle) cabinet design
• Custom Q Acoustics amplifier module: up to 300W continuous / 600W peak power
• Four digital amplifier stages in a parallel bridge-tied load (PBTL) configuration
• THD below 0.1% at rated power
• Dual phase and delay controls for fine placement tuning
• Automatic stereo/mono source detection with gain adjustment
• Adjustable low-pass crossover, 40Hz-250Hz
• Heavy-duty steel chassis driver, 50mm voice coil, aluminium demodulation ring
• 18mm high-density MDF cabinet with 36mm double-thickness baffle and internal dart bracing
• Satin Black finish with black grille

Specifications

Package Contents

• 1x Q SUB120 Active Subwoofer
• 4x Spikes, locking nuts, and spike covers
• 1x Mains cable
• 1x User manual

Documentation

• Official Product Page (Q Acoustics UK)
• Support & FAQs