Condition: Grade A — Great
The speakers present in very good condition. The black gloss lacquer finish shows only slight polish marks — fine surface marks left by cleaning or polishing — rather than any chips, scratches, or deeper damage. Please refer to our photographs for a full assessment of cosmetic condition.
Key Features
The Concept 40’s defining structural feature is its Gelcore cabinet construction. The enclosure is built as two complete layers of MDF, bonded together by a bespoke, non-setting adhesive compound — called Gelcore by Q Acoustics — that never fully cures. When the drivers excite the inner cabinet, the mechanical energy attempts to propagate outward through the enclosure walls; instead of radiating outward as audible colouration, this energy is absorbed by the elastic Gelcore layer and converted into heat. Q Acoustics claims this results in a reduction of cabinet-generated sound of –6dB in the midrange region and up to –10dB at the frequency extremes — figures that contribute meaningfully to the low-colouration character noted in reviews of the Concept 40.
The driver complement is a dual 125mm bass/midrange unit plus a 25mm soft-dome tweeter. The two bass/midrange drivers use bespoke motor assemblies with strengthened magnets developed specifically for the Concept 40, distinct from the equivalent driver in the Concept 20. The tweeter uses ferro-fluid cooling for thermal protection and is mounted with what Q Acoustics describes as “super-decoupling” from the baffle structure — reducing the transmission of mechanical energy from the cabinet into the tweeter motor. The aluminium facia plate running across the front of the speaker is not merely decorative: it forms part of an assembly that clamps a butyl rubber damping sheet against the front panel of the cabinet, further reducing the vibration of the baffle face closest to the listener.
Crossover is a fourth-order Linkwitz-Riley alignment at 2.3kHz. This topology — familiar to loudspeaker designers for its property of summing the outputs of adjacent bands to a flat combined response without phase inversion — keeps the polar tilt through the crossover region well behaved and simplifies system setup.
The speaker is bi-wire and bi-amp capable, with two pairs of terminals at the rear, supplied with shorting links. The reflex port is rear-mounted, and foam bungs are provided: inserting a bung changes the bass alignment to suit placement closer to a rear wall or corner, where an open port can produce an excess of low-frequency output. The integral outrigger base uses safety glass and provides lateral stability while allowing the use of floor spikes for coupling to solid floors, or rubber-tipped feet for hard floor protection.
Technical Specifications
(Source: Q Acoustics official product specification sheet, Hi-Fi Choice, and AVForums review. All sources are in agreement.)
- Type: 2-way reflex (ported) floorstanding loudspeaker
- Drive units: 2 × 125mm bass/midrange; 1 × 25mm soft-dome tweeter
- Frequency response: 53Hz–22kHz (±3dB)
- Crossover frequency: 2.3kHz (fourth-order Linkwitz-Riley)
- Nominal impedance: 8Ω
- Minimum impedance: 4Ω
- Sensitivity: 90dB (1W/1m)
- Recommended amplifier power: 25–150W
- Cabinet construction: Dual-layer MDF with Gelcore damping compound
- Finish: Lacquered black gloss
- Bi-wire / bi-amp: Yes
- Cabinet dimensions (H × W × D): 972 × 170 × 288mm
- Overall dimensions inc. stand (H × W × D): 980 × 390 × 305mm
- Weight: 18.5kg per speaker
- Introduced: 2013
- Country of origin: UK design
Why Buy From Us
With over 40 years of experience in the Hi-Fi industry, we are well placed to assess and test equipment of this type. Every item we list is fully inspected and tested before sale — this pair was checked by Hilton in our workshop.
When you buy from us you can expect:
- Full inspection and testing prior to listing — not simply a visual check
- A 3-month guarantee on every item we sell
- Transparent descriptions with no omissions
- Professional packaging to ensure safe delivery
- After-sales support available by phone or email should you have any questions
Summary
This is a matched pair listed as a single lot. The Q Acoustics Concept 40 remains a well-regarded floorstander that attracted strong notices on its release for the combination of its low-colouration Gelcore cabinet, competent driver design, and accessible sensitivity and impedance figures. At 90dB nominal sensitivity and 8Ω nominal impedance, it is compatible with a wide range of amplifiers from around 25 watts upward, though a good-quality 50W or above amplifier is recommended to get the best from the design. Please feel free to get in touch with any questions prior to purchase.
