Hardware Reviews

Q-Acoustics Concept 500


Having established itself as a highly credible entry level to mid market brand Q-Acoustics has rather rashly gone and built a high end loudspeaker. This is fabulous news for the canny audio enthusiast but is tricky terrain from a commercial perspective. The nearest parallel I can think of is the Ford GT40, a seriously capable car by all accounts but not one you ever see on roads that are no stranger to Ferraris, Lamborghinis and the like. There is a more positive role model in the Audi RS8 however, a car that comes from a less humble brand than the GT40 of course.

In audio the best comparison is the Rega RP10 turntable and arm, one of the very best in the audio universe but at £4,000 it’s never going to be put up against the high priced products that it’s on a par with. That’s how good the Concept 500 is, if it came from a boutique brand and cost two to three times as much you’d have to form an orderly queue to get one.


C500 driver close up 3


So how has Q-Acoustics made the leap? Essentially it has given freelance speaker guru Karl Heinz-Fink a bigger budget, and he has run with it. There are more great ideas in this speaker than whole ranges from other brands, for instance rather than sticking bracing into the cabinet in a conventional fashion, this design employs point to point bracing precisely where it’s needed by analysing where the greatest flex is in the cabinet walls and reinforcing those point. These braces are also used to anchor the mid/bass drivers with tensioning springs, and lock nuts that pull the drivers into the cabinet, there are no fixings around the outside of the chassis. The drive units themselves aren’t anything fancy in terms of materials, it’s a coated paper cone, but they do have larger than average 35mm voice coils on a glass fibre former. The coil wire is copper clad aluminium that’s doubled up with two coils in parallel and has a copper cap and an inductance ring to reduce distortion, but again this isn’t revolutionary.

The tweeter is not one I’ve seen elsewhere because it was developed for this loudspeaker, it’s a fabric dome with a wide surround that is designed to give broad dispersion. The voice coil is again wider than usual at 28mm and most controversially the magnet is a ferrite rather than the more fashionable neodymium type found on most high end tweeters. Which makes me wonder if the tremendous intelligibility that the Concept 500 imparts is related to this fact, more likely is that it’s a sum of the parts situation.


C500 base terminals


The biggest part here is the sumptuously finished box, this is bigger and heavier than average because it’s built with a triple laminate of Gelcore damped MDF. Gelcore first appeared in the original Concept models where there were two layers of wood and one of this silicone like material. For the big Concept Q-Acoustics have added another layer of both wood and Gelcore to make the cabinet as ‘quiet’ or minimally resonant as possible. As well as the aforementioned bracing the cabinet contains Helmholtz pressure equalisers, essentially tubes stuffed with damping that even out the air pressure within the cabinet. This is not apparently a new technology but neither is it something you often see. A bit like the huge reflex port that you can stick a cricket ball into (100m diameter), this is provided to avoid compression at high SPLs apparently. You see similar on a few high end speakers but they’re scarce at this end of the scale. The other obvious feature is a large rounded plinth in cast aluminium, this is to give the speaker stability and to help it pass tilt tests without unattractive outriggers, it’s supplied with spikes or ball end metal feet, I used the latter.

Cable connections are bi-wire ready and placed usefully low down on the cabinet. There is also a jumper for adjusting tweeter output by half a decibel up or down, which gives it a degree of room tuning capability, albeit not in the bass where room problems are hardest to rectify.

The Concept 500 proved a little more fussy about positioning than average in my room, it doesn’t like being near walls as you’d expect with that big port. I found that a gap of 560mm (22 inches) between the back and the rear wall worked well, the bass on this speaker is generous but not overblown so long as you give it room to work in. In fact the bass is absolutely gorgeous, rarely have I encountered a speaker that breathes so well, has such open and warm bass yet is tight and controlled. It seems to have a freedom that you rarely find and which gives it the ability to articulate bass notes of all varieties in a totally convincing fashion. Usually you can have tight, solid, muscular bass from a big speaker or leaner, faster less powerful bass, but this seems to combine both qualities. It’s not quite as authoritative as the best speakers in its size range but they are considerably more expensive, ultimately the driver size limits absolute extension but you will be hard pressed to match it with another speaker at close to this price.


Concept 500 wht


This is also a phenomenally revealing loudspeaker, it’s almost as if some trickery is at hand when you can comprehend lyrics that you’ve played too many times yet have previously been unclear. It certainly produces unusually open sound, the better the partnering amp in this regard the more obvious this becomes. Most of my listening was done with the ATC P1 150 Watt power amp I use as a reference but I also tried the rather special Leema Tucana II Anniversary with its fabulous speed, and a new Danish amp from Phison, a 120 Watt high end lump that really opened up the Concept 500 a treat. It’s one of those speakers that lets you know all about the quality of the hardware in the system and the recording it’s playing without sounding dry or analytical, quite the opposite, it’s thrillingly musical and engaging.

This takes a little while to become apparent though, the Concept 500 is a subtle speaker, it doesn’t grab you on first listen, but after half a dozen familiar pieces you realise that it’s got you hooked. I used it with a Melco N1ZH music server and the rather fabulous CAD 1543 MkII DAC that has become a reference for me. Preamp as ever is the Townshend Allegri and analogue cabling came from the same source, USB digital is by Vertere. It was easy to hear the calibre of these elements and every tweak I tried was more than obvious too, but more of that another day. Getting back to the big Qs and the Leema amp things were very interesting indeed, Bugge Wesseltoft and Henrik Schwarz’s Duo album of electronica, samples and piano sounded fabulous. Acres of reverb spread out from the soundstage whilst the finest details were presented in total coherence. It seems as though a particular type of distortion that you take for granted with most speakers has been erased or significantly reduced. Distortion levels across the band are in the league of a good electrostatic, yet no electrostatic has bass of this magnitude and quality nor can many of them handle power with such ease. I didn’t play them at full chat all the time but the level kept creeping up because perceived distortion is so low. This track prompted me to note “this speaker is better than I thought”, that’ll be the slow burn and the effortless level then.


C500 base loop


The few shortcomings that I could find included less than pin sharp imaging and less than total authority in the bass, but this was only apparent by odious comparison. Once you start playing your music through the Concept 500 it’s very hard to stop, not only does it reveal so much of the shape, colour and nature of each recording but it does so with perfect timing, the bass line is always in sync with the rest of the rhythm notes so everything hangs together in highly convincing fashion. This is not even a difficult loudspeaker to drive as I discovered when I gave it a spin with a Quad VA-One integrated, a 15 Watt tube amp with onboard DAC. This further enhanced the speaker’s quicksilver ability to start and stop, and added a sweeter midrange. The bass wasn’t quite as well defined as with transistor amps but it made up for this with beautiful flow and an all round sense of naturalness. This combination really drew me into the music, revealing the minutiae without undermining the bigger picture, and even if the bass isn’t muscular it’s substantial enough to do justice to non acoustic music.

As well as all this, and it’s a lot, this is a very nicely designed and executed loudspeaker. It’s not small but it’s simple lozenge shape and one third veneered finish courtesy of designer Keiron Dunk means that it doesn’t impose too much. And the shiny base is a lot prettier than your average speaker stand. So all in all this is an exceptional loudspeaker regardless of price, don’t let the fact that it’s relatively affordable give the impression that this is another also ran product. I don’t often get products that I desperately want to keep hold of but this is one of them, so can anyone who knows the secret of winning the lottery get in touch please, it’s an emergency!


Type: 2.5-way, 3-driver, floorstanding bass reflex loudspeaker
Driver complement: 28mm soft dome tweeter, 2x 165mm mid/bass
Crossover frequency: 2.5kHz
Frequency response: 41Hz – 30kHz (-6dB/+3dB)
Impedance average/minimum: 6 Ohms/3.7 Ohms
Sensitivity: 90dB/W/m
Dimensions (HxWxD):  1150 inc plinth x 198 x 350mm
Weight: 42kg/each
Finishes: Piano black + deep rosewood veneer, piano white + pale oak veneer

Price when tested:
Manufacturer Details:

T +44 (0)1279 501111


floorstanding loudspeaker


Jason Kennedy

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