Q Acoustics Q SUB80 Subwoofer Satin Black

The Q SUB80 is the most compact model in Q Acoustics’ Q SUB series, a trio of active subwoofers designed to complement the brand’s speaker ranges from the 3000i through to the 5000 series. Sitting below the 254mm Q SUB100 and the 305mm Q SUB120, the Q SUB80 pairs its 203mm bass driver with a custom-designed 200W continuous (400W peak) Class D amplifier module, making it a natural partner for smaller rooms or desktop audio setups built around the M20 or M40 active speakers.

Amplifier & DSP

The amplifier module is entirely custom-designed by Q Acoustics and integrates a digital signal processor, power amplifier, and power supply into a single unit. Four digital power amplifier stages operate in a parallel bridge-tied load (PBTL) configuration, a topology that reduces output impedance and heat dissipation while improving driver control. The result is 200W of continuous power and 400W peak, with total harmonic distortion held below 0.09% at rated power. A sophisticated DSP algorithm automatically detects whether the input signal is stereo or mono and adjusts system gain accordingly, ensuring optimal signal-to-noise ratio and dynamic range regardless of the connected source.

Driver Design

The 203mm bass unit is built around a heavy-duty steel chassis with a paper cone and rubber surround. A 38mm voice coil provides the motor force, while an aluminium demodulation ring reduces inductance-induced modulation distortion for cleaner, more controlled bass output at higher excursion levels.

Room Integration

Subwoofer placement in a room can significantly affect sound arrival timing and phase alignment, leading to uneven frequency response. The Q SUB80 addresses this with DSP-driven dual phase and delay controls alongside a phase inversion switch, allowing precise alignment with partnering speakers without requiring professional calibration. The low-pass crossover is adjustable from 50 Hz to 250 Hz, setting the −6 dB roll-off point to blend seamlessly with any speaker system.

Cabinet Construction

The sealed infinite baffle enclosure delivers tight, focused bass without the port turbulence associated with reflex designs, and its portless form factor simplifies placement near walls and furniture. The cabinet is constructed from 18mm high-density MDF with a 36mm double-thickness front baffle for maximum rigidity. Internal dart bracing further stiffens the structure, reducing panel resonance and cabinet ballooning under the high internal pressures generated at full output.

What the Press Says

• Highly Recommended — AVForums