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Q-Acoustics Concept 40 Speaker Review


A year or so back I reviewed the first of the Concept series speakers from Q-Acoustics, the Concept 20. That model has similar drivers to the company’s 2020i budget stand-mount but a more sophisticated cabinet design, something which doubles the price but also doubles the resolution by halving the cabinet induced distortion. The Concept concept is a means of minimising the biggest source of colouration in most affordable loudspeakers, put your hand on a speaker that’s playing music and you can feel it vibrate. That vibration creates noise, a crude echo of the signal being delivered by the drive units, it blurs the sound because while quiet it’s still loud enough to be audible. This is why speakers tend to have narrower baffles than they used to and why smaller speakers can often sound better than bigger ones, there’s less vibrating wood joining in with the music.

Q-Acoustics has tackled this by building a cabinet within a cabinet and separating the two with material they call Gelcore, a mastic like non-setting adhesive that damps vibration in the structure. As Q-Acoustics’ Steve Reichert puts it, cabinet resonance is the elephant in the room, and he’s right. Look at high end loudspeakers from the likes of Vivid, Magico and Wilson benesch, they all use alternative materials to wood in an attempt to get rid of the resonances that are so hard to repress in that material. By isolating the inner from the outer cabinet Q-Acoustics has taken the bull (elephant!) by the horns and done more than virtually any other maker of affordable loudspeakers to arrest that resonance.


The original aim with the Concept 40 was to make a Concept 20 with more bass, so they made a bigger Gelcore box and added a second bass driver as well as Gelcore bracing inside. This however didn’t give designer Karl Heinz-Fink the increase in bass that was desired so he had to revamp the bass unit by using a much larger magnet. This did the trick while increasing efficiency to a useful 90dB, meaning it doesn’t need a particularly power amplifier to deliver high levels, having an impedance that doesn’t drop below four Ohms helps as well.

The Concept 40 cabinet is made up of two 10mm MDF lozenge shapes with Gelcore bonding, an 18mm rear baffle and a 22mm front one. The aluminium plate around the drivers is not just for decoration, it is damped by a butyl rubber sheet and acts to calm resonance in this critical area. Q—Acoustics chose to go for a three point support on this speaker, which means it will never wobble and that they only need two outriggers to ensure stability. The use of glass for the rear ‘wings’ gives rigidity as well as the potential to blend in with the background, it’s an unusual place to use it but it works. The finish on the Concept 40 is exceptional, clearly superior to the competition, so long as you like lacquered paint that is, there’s no veneer option but that’s fine by me. It combines nicely with the glass and chrome spike holders to give a distinctly high quality feel, even the tapered port entry is finished to match.


Q-Acoustics’ recommendation for set up with this speaker is pretty radical, not unique but so extreme as to be difficult to accommodate in a shared living space. They suggest you put the speakers at the corners of an equilateral triangle with the listening seat at the top, with the same distance between each point. In practice this means the speakers end up a long way into the room but close to side walls. The idea being that you get the greatest scale and image precision by doing so, and it works. It probably works with other speakers as well although smaller models usually require more boundary reinforcement to deliver decent bass.

In the Concept 40 case a good recording will produce astonishing openness and imaging with massive depth and height. It’s a pinpoint image but not one that’s etched in the air by treble alone, the bass is very good on this speaker and as a result the imaging has a tactile solidity that is reach out and touch it real. Peter Gabriel’s voice on his version of Heroes (Scratch My Back) has extraordinary palpability, and the strings behind him have real body too, which all adds up to considerable emotional power from the piece overall. These really are speakers you can ‘sit on top of’ and enjoy. Deeper bass was supplied by the organ on Philip Glass’ Koyaanisqatsi which has real gravitas in the Concept 40’s hands, I do like a speaker that can move air. It’s also pretty adept in the mid-band, delivering the vibrancy of drums, their kick and power in the context of an open sound-stage. The bass is not the fastest around but timing doesn’t suffer unduly as a result and the imaging is so strong that you find yourself immersed in the sound.

With vinyl from Rega’s remarkable RP8 turntable you get a beautiful sonic vista, especially with a nice recording like Laurie Anderson’s Strange Angels. This creates an expansive sound-field populated by sparkling percussion and big, round bass notes behind an ethereal voice. The fretless bass is particularly appealing, as is the ‘pop’ of the tabla on Monkey’s Paw and the massive kick drum sound – it’s quite a production and one that the Concept 40 revels in.

Placing this speaker more conventionally, in essence further from the listener and closer to the rear wall, reduces the image scale somewhat but doesn’t undermine things very much. There’s still plenty of power and the bass is slightly reinforced by the proximity of the wall. I contrasted it with Bowers & Wilkins 684 S2 in this position, the newcomer sounding more detailed but less extended in the bass. It requires more power than the Q-Acoustics but those looking for fine detail might prefer its presentation. The Concept 40 does however have a more fulsome and juicy style that is easy to enjoy and will be less critical of lossy formats such as MP3 – the wider the window the more the limitations of such formats become apparent.

I thoroughly enjoyed this attractive floor-stander, it’s relaxed, open presentation makes it easy to enjoy all manner of material and its reach in the bass means that you get plenty of weight behind low notes. You can get a more pacey, edge of seat sound with some alternatives but few compete with this when it comes to suspending disbelief and allowing yourself to be carried away by the music.


Enclosure type:       2-way reflex with double woofer

Bass Unit:       2 x 125mm

Treble Unit:    25mm

Frequency Response:     53Hz – 22kHz

Nominal Impedance:      8ohm

Minimum Impedance:    4ohm

Sensitivity:     90dB

Recommended Power:    25 – 150w

Crossover Frequency:     2.3kHz

Dimensions H/D/W mm: 972 x 170 x 288

Weight:   18.5kg

Finishes available: Lacquered Black Gloss / Lacquered White Gloss

Warranty:       5 Years



Q Acoustics

T: 01279 501111


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