The Q Acoustics M40 sits at the top of the M Series, above the compact M20 bookshelf speaker. Where the M20 targets desktop and small-room listening, the M40 is a powered micro-tower designed to deliver full-range, room-filling sound from a cabinet just 71cm tall — small enough to tuck beside furniture yet tall enough to fire at ear height from a seated position without stands.
Driver Technology & Enclosure
Each M40 tower uses a two-way reflex-loaded enclosure carrying dual 125mm mid/bass drivers and a 22mm decoupled tweeter, crossing over at 2.5kHz. The mid/bass units feature Q Acoustics’ C³ (Continuous Curved Cone) geometry — a driver profile that eliminates the flat section found on conventional straight-sided cones. By curving continuously from the surround to the dust cap, the C³ cone distributes resonant modes more evenly across its surface, reducing the concentrated breakup peaks that colour the upper midrange on traditional drivers.
The enclosure itself uses Point-to-Point (P2P) bracing, a construction method where internal braces connect opposing cabinet panels at calculated stress points. This targets the specific panel resonance modes excited by the drivers, achieving greater cabinet stiffness than conventional ladder bracing for less added mass. A Helmholtz Pressure Equaliser (HPE) tube mounted inside the cabinet acts as a tuned absorber, reducing the standing-wave pressure peaks that build up in the internal air volume at low frequencies.
Built-in Amplification
The M40 is a fully active system — no external amplifier is required. The primary (powered) speaker contains Class D amplification rated at 2 × 100W peak (2 × 50W RMS), driving both the internal drivers and the passive partner via an included 4-metre speaker cable. A rear-panel EQ switch lets the system adapt its bass response depending on whether the speakers are positioned in free space, against a wall, or in a corner.
Connectivity
Wireless streaming is handled by Bluetooth 5.0 with support for aptX HD (24-bit/48kHz) and aptX Low Latency codecs alongside standard SBC and AAC. Wired connections include optical TOSLINK (24-bit/192kHz), USB Type B (24-bit/192kHz), analogue RCA phono inputs (700mV RMS sensitivity), and a 3.5mm auxiliary jack (400mV RMS sensitivity). A subwoofer output (1V RMS maximum) is provided for optional bass reinforcement. The system ships with a remote handset.
In the Box
The M40 package includes one powered speaker, one passive speaker, a 4-metre speaker cable, a remote handset with batteries, four rear stabilisers, eight M5 screws, eight spike feet with covers, two foam bungs for the reflex ports, and UK and EU power cords.
What the Press Says
- What Hi-Fi? ★★★★☆
- AVForums Best in Class
- StereoNET Applause Award
| Enclosure Type | 2-way reflex (ported) |
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| Mid/Bass Drivers | 2 × 125mm C³ Continuous Curved Cone |
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| Treble Unit | 22mm decoupled dome |
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| Crossover Frequency | 2.5kHz |
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| Frequency Response (-6dB) | 38Hz – 22kHz |
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| Peak Power Output | 2 × 100W |
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| Rated Output Power | 2 × 50W RMS |
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| THD @ Rated Power | <0.7% |
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| Amplifier Type | Class D |
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| Bluetooth | 5.0 (aptX HD, aptX Low Latency, SBC, AAC) |
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| Optical Input | TOSLINK — 24-bit/192kHz max |
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| USB Input | Type B — 24-bit/192kHz max |
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| Analogue Inputs | RCA phono (700mV RMS), 3.5mm jack (400mV RMS) |
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| Subwoofer Output | 1V RMS maximum |
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| Dimensions (W × H × D) | 250 × 710 × 296mm |
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| Weight (Powered Speaker) | 12.4kg |
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| Weight (Passive Speaker) | 11.8kg |
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| Power Supply | 100–240V AC, 50–60Hz |
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| Standby Power | <0.5W |
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| Typical Power Consumption | ~10W |
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| Also Available As | Black, White |
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