Q Acoustics has spent the past two years updating its lineup with the award-winning 5000 series and brand new 3000c series, and the market has responded with great enthusiasm. The Q Acoustics M40 earned our “Editor’s Choice” Award in the best wireless speaker category, and there’s no question that it could be the foundation for a high-value 2.1 system for those who have space challenges. The one thing missing from that is a high-quality subwoofer to fill in the bottom range. The Q Acoustics lineup has been slightly thin in that regard, but all of that changes with the new Q Acoustics Q SUB Series.
The Q SUB lineup consists of three interrelated models: the 8-inch Q SUB80, the 10-inch Q SUB100, and the flagship 12-inch Q SUB120.
Cabinet Design
The Q SUBs incorporate an infinite baffle (sealed box) design. Acoustically, this supports tight and more focused bass response, and coupled with the DSP allows for very precise tuning to achieve the best acoustic response possible. With a sealed box design, the Q SUBs are also easier to place near walls or closer to the corners of your listening space.
Cabinet Construction
The cabinets for the Q Subs are made from high-density 18mm MDF (Medium Density Fiberboard) with a 36mm double-thickness baffle to provide rigidity. Internal dart bracing provides additional support for the mechanical grounding of the drivers, as well as mechanical stability and reduced cabinet ballooning.
This supports optimal performance under high internal pressure. The sealed enclosure also prevents air leaks through the amplifier mountings, while the 15mm MDF grilles are tightly fastened to prevent rattling. Adjustable locking spikes and spike cups are provided for floor leveling and protection.
Driver Design
The subwoofer drivers have a heavy-duty steel chassis, paper cone, and rubber surround. Driver diameters are 203mm (Q SUB80), 254mm (Q SUB100), and 305mm (Q SUB120). The voice coils are 38mm for Q SUB80/100 and 50mm for Q SUB120, with an aluminium demodulation ring for reduced inductance-induced modulation distortion.
Power Amplifier
The Q SUB amplifier module is custom-designed by Q Acoustics. It incorporates four digital power amplifier stages in a parallel bridge-tied load (PBTL) configuration, enhancing efficiency and speaker control by reducing output impedance and heat dissipation. This design can deliver up to 300W continuous and 600W peak power, with THD performance of less than 0.1% up to 300W.
Integration
With a minimalist, clean design and choice of Satin Black or Satin White finishes, they blend into almost any room decor. Placement also impacts integration as it affects sound arrival timing and phase alignment. The Q SUB Series employs Digital Signal Processing (DSP), alongside fine delay adjustments and a phase inversion switch that allows better sonic refinement.
Frequency Response Adjustment
The Q SUB series features a low pass filter with frequency adjustment from 40 Hz to 250 Hz, setting the -6 dB point. This ensures that the Q SUBs can blend with and complement the low-frequency response of the rest of the speaker system.
Source Detection
Subwoofers need to adapt to different sound input sources to deliver the best possible bass. This includes sources provided by stereo preamp outputs or mono feeds from active speakers or home cinema systems. To support this, Q Subs provide a complex algorithm inside the DSP to identify the input signal type – stereo or mono and the level and automatically adjusts system gain.
Standby Modes
The Q SUB provides multiple standby modes to suit various system needs. Auto detection turns the subwoofer on when a signal is detected. Also, after 20 minutes, the subwoofer goes back into standby mode with a minimum of power to support the auto detect mode.
In addition, a 12-volt trigger is included to power up the subwoofer if a trigger signal is detected.
Also, if you prefer, the standby and trigger modes can be bypassed, and the subwoofer can remain on if desired, but of course, that consumes more power.
Protection
An intelligent protection system is included that monitors the electronics in real time. This ensures that the amplifier and power supply are fully protected in the unlikely event of an excess of temperature.
Comparison
| Model | Q SUB80 | Q SUB100 | QSUB 120 |
| Price | $899 | $1,049 | $1,199 |
| Enclosure type | Infinite Baffle (Sealed) | Infinite Baffle (Sealed) | Infinite Baffle (Sealed) |
| Bass Driver Diameter | 203 mm (8 in) | 254 mm (10 in) | 305 mm (12 in) |
| Effective Volume | 13.9 litres | 23.5 litres | 44.1 litres |
| Max SPL @ 1 m | 107 dB | 111 dB | 114 dB |
| Frequency Response (- 6dB) | 36 Hz – 250 Hz | 32 Hz – 250 Hz | 28 Hz – 250 Hz |
| Low Pass Crossover range | 50 Hz – 250 Hz | 40 Hz – 250 Hz | 40 Hz – 250 Hz |
| Peak Amplifier Power | 400 W | 500 W | 600 W |
| Continuous Amplifier Power | 200 W | 250 W | 300 W |
| THD @ rated power | 0.09% | 0.09% | 0.09% |
| Input Sensitivity (max gain) | 300 mv rms | 300 mv rms | 300 mv rms |
| Maximum Input Level | 2.1 V rms | 2.1 V rms | 2.1 V rms |
| Input Impedance | 20 kΩ | 20 kΩ | 20 kΩ |
| Noise floor (A wtd) | 50 μV | 50 μV | 50 μV |
| Dimensions (HWD) | 315 x 315 x 347 mm (12.4 x 12.4 13.6 in) |
350 x 350 x 382 mm (13.7 x 13.7 x 15 in) |
400 x 400 x 432 mm (15.7 x 15.7 x 17.0 in) |
| Weight | 15 kg (33 lbs) |
16.7 kg (36.8 lbs) |
22.5 kg (49.6 lbs) |
The Bottom Line
Subwoofers have become more popular over the years with consumers who don’t have a lot of space for their primary bookshelf or floor-standing loudspeakers but crave the bottom octaves to enhance their music-listening and movie-watching experience.
One of the biggest issues with any subwoofer is set-up; following some basic set-up rules can make this process a lot less painful and also maximize the performance if your listening room is somewhat problematic when it comes to acoustics.
Q Acoustics has not promoted its subwoofer lineup over the years quite as aggressively as their other products – but we think that is about to change with the new Q SUB series lineup that is competitively priced.
If you already own a pair of Q Acoustics 5000 or 3000c Series loudspeakers, these might be the final piece of the puzzle worth considering.
Pricing & Availability
Previously released Q Acoustics Subwoofers that may still be available include:
All Q Acoustics products are available from selected independent retailers or www.qacoustics.co.uk (UK) and www.qacoustics.com (US)
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