Q Acoustics Concept 500 loudspeaker ~ The Sound Advocate

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Q Acoustics Concept 500 loudspeaker is the company’s top-of-the-line Floorstander and truth be told, it truly packs an amazing wallop! Howard Milstein undertakes an in-depth review

Q Acoustics have until now concentrated on designing and marketing loudspeakers that most would agree focused on the budget end of the market. (e.g. the 300i series). The Concept 500 was created with a focus on striking the ideal balance between science and art in order to create a loudspeaker that would be fashionable, modern, excellent-sounding, and accurate with less attention on pricing.

The Concept 500 nonetheless needed to be viewed as a good value in its substantially higher-end target market to escape the constraints of designing for lower price points. And so, the journey began into this eclectic design.

This is the first Q Acoustics loudspeaker I have listened to and careful attention was subsequently applied to their placement in my room as well as the components that were used in conjunction with the speakers. To put it mildly, extra special time was taken in every respect. The resultant sound quality dividends and pitfalls, if any, will come later on after we explore some of the more interesting technical details that went into the effort of this design.

THE ESSENCE OF THE CABINET DESIGN

Natural wood cabinets are favored by some high-end speaker manufacturers as a superior building material, while others disapprove of them in favor of vastly more expensive and exotic substitutes. There are advantages and disadvantages to this method.

According to Q Acoustics, fiberboards like MDF have an advantage over wooden panels. They are not only even easier to cut, fit, and finish but also highly well-damped and shield against high Q resonances due to the composition’s partial heterogeneity. These materials are chosen by Q Acoustics over more specialized ones that only increase mass and expense with no sonic benefit.

To reduce undesirable acoustic reflections, the Concept 500’s cast aluminum base is made without a lot of flat surfaces or decorative elements. A selection of carefully constructed feet is used to support the resulting sleek shape and to immovably connect the loudspeaker to any surface.

The Concept 500 is suitable for contemporary living spaces and does not follow any particular interior design aesthetic, as can be seen in the photographs. The loudspeaker still has a slim and substantial appearance, but it has been tastefully streamlined. The speaker’s baffle is kept clear by rear-mounted mid- and bass speakers, while the grille is held in place by integrated magnets rather than any visible fasteners. Italian real wood veneer has been combined with either gloss white or gloss black finishes.

Q ACOUSTICS P2P™ BRACING

The Fink Audio-Consulting team was employed to use unique computer models that may be simply repeated to forecast appropriate cabinet building and stiffening techniques.

The specific performance of the cabinet structure can be minutely and carefully examined using Finite Element Analysis and Laser Interferometry to identify the precise locations that require support and those that do not.

Q Acoustics Concept 500 loudspeaker Cabinet view

The resulting bracing technique, dubbed Q Acoustics P2PTM (Point to Point) bracing, solely supports the cabinet elements that require stiffening and does not arbitrarily disperse undesired energy.

Dual Gelcore™ FOR CABINET NOISE

While Q Acoustics P2PTM bracing addresses lower frequency panel vibrations, Dual GelcoreTM, a development of the GelcoreTM technology that has been engaged with great success in the Q Acoustics Concept 20 & 40 loudspeakers, addresses higher frequency cabinet noise.

Three different layers make up the speaker cabinet. A compliant non-setting gel is applied under pressure to entirely cover the spaces between the layers. Due to the two restricted layers’ ability to transform higher frequency vibrations into heat that is then dispersed, the speaker cabinet’s walls are effectively dampened within the damping gel.

DRIVERS

The Concept 500 is a two-way system employing a 1″ soft-dome tweeter and two 6.5″ mid/bass drivers, the three drivers arrayed in a vertical D’Appolito configuration: a column with the tweeter in the middle between two mid/bass drivers.

According to the Q Acoustics “White Paper, the 165mm mid/bass drive units were initially created expressly for the Concept 500 project following a strategy of exclusive research, ensuring that every facet of the design was catered to Q Acoustics’ specifications.

The cone is carefully crafted from impregnated and coated paper, and it is surrounded by a recently created low-hysteresis rubber surround that aids to lessen unwelcome cone resonances. The voice coil’s 35mm diameter is unusually huge in this case. This enables more “shove,” or higher power handling, and less dynamic compression.

Instead of Kapton® or aluminum, Q Acoustics decided upon a voice coil made of glass fiber, which provides the required rigidity without the negative consequences of eddy currents inside the former.

A somewhat unusually styled 2+2 copper-clad aluminum winding (CCAW) is applied to the voice coil along with parallel winding of the two dual layers of CCAW conductors. Theoretically, this increases the voice coil’s force for a given input of current over a typical dual-layer winding without adding more bulk. Ironically, this configuration can occasionally result in more distortion, but it can be avoided by adding a copper cap to the top of the pole piece and an aluminum inductance compensation ring to the motor system.

HIGH FREQUENCIES

This loudspeakers upper mid to high frequency tweeter was also custom developed by Q Acoustics. To be quite blunt, this is no easy task. In this case, Finite Element Analysis was used to model the acoustic performance of the soft dome and surround for optimal axial dispersion. Too narrow a high frequency dispersion characteristic means the speaker will not drive the room well, making it sound flat and uninteresting unless the listener is sitting in the exact ‘sweet spot’. (Although for the most accurate stereo imaging, there is usually “one spot” that is most ideal) The high frequency drive unit’s extra wide surround contributes to the dispersion of upper frequencies, for flattening the response off-axis

In particular at the lower end of the frequency range, the 28mm voice coil, which is bigger than typical one-piece coated-microfibre dome, and wide surround provide better power handling capability, lower dynamic compression, and consequently lesser distortion. (more on this tweeters sound experience further on!)

SETUP

The Concept 500s are a pretty hefty loudspeaker and although its steel base (nicely attached to the plinth) is very helpful and solid for maneuvering these towers, it will take a little time to move them around to their ideal listening position, quite patiently, I might add.

I was quite enthused when I finally got them into a perfectly aligned position in my room, that being about 1 meter or more from the back wall and about a touch less than a meter from the side walls. This took a bit more time to establish than I had expected as proper positioning of the ‘500’ in your room is somewhat more important than Q Acoustics mentions in their manual. After a short, 3-hour initial listen, I found the treble a bit too prominent, even with the high-frequency jumpers removed from the back of the speaker cabinet.

Looking at the back panel of this speaker we see three terminal holes for a jumper that as mentioned above, can be used to increase the high-frequency response by a tiny, half a decibel up or down. The designers stated “normal” setting for the jumper is inserted on the left/center position but eventually, I found myself listening to the Concept 500 without any jumper terminals inserted. This effectually gives the listener a bit “less” treble response for rooms that are supposedly not as furnished or “treated” and thereby slightly diminishes the high frequencies accordingly.

Q Acoustics Concept 500 loudspeaker back view

Don’t be to troubled with this. The 500 treble is quite accurate but if the speakers are not fastidiously placed to exact measurements in your own particularly treated room, they can be a touch “fizzy” in some listening situations with some program material and so it was with my commencing experience. Keeping the jumpers off kept the treble much smoother and very tidy on almost all the best program sources I used in the listening tests. However, take note that the Concept 500’s upper mid/treble balance can be ruthlessly revealing of inadequate and/or poor recordings.

With more hours of listening stacked away and the speakers still breaking in, I proceeded to make some small but pertinent locational adjustments to the speakers and my listening position. Now, things started to appropriately blend into place quite considerably while the treble was toned down nicely.

As is always preferred with the most competently designed models, these speakers should be slightly angled toward the listener’s ears for the best stereo imaging and sound stage reproduction. In my situation, this formed an isosceles triangle. My listening seat was about 11 feet from the front baffle at first. Later on, my chair was moved in a foot or two and everything started coming together. With an 8.5-foot separation between the loudspeakers, I was finally ready to sit down and start loading program sources to begin the sound expedition.

It should be pointed out that the Concept 500 is equipped for bi-wiring or bi-amping with electrically isolated and oversized HF and LF terminals which can accept bare wires, spades, or 4 mm banana plugs. If connected using a single run of cable the best performance will usually be obtained using the bi-wire links attached which are in a default position on the speaker. Though bi-wiring is advised, I proceeded to use single wiring for most of my listening time using the quite excellent Argent/Pur (review forthcoming) silver stranded 12 gauge loudspeaker cables.

Q Acoustics Concept 500 loudspeaker port

A large two-piece foam bung can be used to adjust the size of the bass reflex port, which is located in the back. The port is almost entirely blocked off when both portions are in use, but some flow is possible when the middle section is removed.

LISTENING SESSIONS

It would be an underestimation of this loudspeaker’s stunning capabilities for a floorstander at its suggested retail price to state that the Concept 500 gives a sublimely accurate sound experience upon subsequent auditioning!

Immediately, one becomes aware of its huge soundstage and how it almost disappears from its solidly built enclosures. There can be little doubt that the cabinet design and bracing have much to do with this. As you look towards the speakers and the music emanates to the listening seat, the stereophonic images are promptly placed in the exact formation of a full orchestra playing before you. Turn the lights down low and this stereo illusion becomes, even more, three-dimensional. Stringed instruments particularly massed strings are sumptuous, resonant, and exceedingly ambient within a live recording concert stage. The harmonic structure of other orchestral instruments is lavishly and accurately formed in the midrange tonality.

As my first musical example, listen to this extraordinary live recording that is of ‘demonstration’ sonics, which can be downloaded; even—in its mp3 format @ 320 kbps at 16 bits (converted to a WAV file). Jinich Hirokami conducts the NHK Symphony Orchestra in Shuberts Symphony 5 in b flat (D.485) off of youtube. This is a standout musical performance that allows the Concept 500’s to bring the concert hall into your room. The soundstage offers a huge, vast orchestral spread and magical instrumental tonality being simply thrilling to listen to. Kudos to the recording engineer and Concept 500’s ability to display this live performance!

The speakers are dynamic yet subtle in their wonderful midrange response. Voices are true and realistically produced with a beautifully carved, smooth buttery sound with depth, and structural tonality on sopranos and distinctively reproduced male tenors and bass singers. Listen to Charles Gerhardt conducting Bernard Herrmann’s classic film scores with soloist Kiri Te Kenawa.

It was recorded by the famous Kenneth Wilkenson (1974) with the ‘Decca Tree’ microphone formation and the Concept 500 is startling in reproducing her vocals on the aria “Solombo” from Citizen Kane. The speakers almost vanish before you and her voice is enveloped in stupendous depth and lushly warm ambiance. A speakers sound in this class is virtually unheard of at its respective price point!

The bottom end is superbly tuned as well. Bass notes are deep and taut like it ought to be yet only shows up when the source material demands it to be so. Nevertheless, you’ll need to give that bass port facing back plenty of breathing area as stated in my setup above. Again, keeping them at least a meter away from walls will give a solid bass response from the best recordings be they vinyl or digital.

Let us talk about the stereo imaging of the Concept 500. Similar to my last review of the Qln One loudspeaker, when the speakers are properly and securely positioned, and I mean to the millimeter and angled in slightly towards the listening position, the speakers’ image specificity and locational effects are second to none. Vocalists are perfectly centered when recorded as such and orchestral soloists are placed exactly within the huge depth and width of the soundstage. On well-recorded program material, (eg. the latest HDTT of Beethove’s 4^th piano concerto and Mozart’s 25^th), the whole orchestra is perfectly placed and yet the string section will span the whole left width of your listening room. In fact, this is as good as it gets.! I could name another five or six sources that will give you similar results. Simply fantastic stereo is available from the Concept 500 when it is asked to do so.

Q Acoustics Concept 500 loudspeaker — Rosewood Finish

Well-recorded material sounds startlingly immediate thanks to the speakers’ lack of coloration, although the overall sound balance seems to be a little recessed generally speaking. In actuality, the speaker’s acoustical presentation is improved by this. However, while playing challenging piano pieces, the piano can come directly to the main line of the sound field or go back a little, depending of course on how it was recorded, which additionally helps the depth of the image to travel far behind the front wall.

Because of the speaker’s obvious transparency, it will replicate any harshness or aggression present further up the audio chain, but when used in conjunction with the necessary equipment and with careful location, it can be a quite forgiving speaker.

No, It won’t be a panacea to fix a broken system since it’s very probable that the problems you’re trying to fix will only make themselves more obvious. I bring this up because, with some extremely improper recordings and/or setup, the higher treble response can once in a while sound a touch gritty.

On the other hand, the full range of the speaker is so engaging that it would be hard to complain (or notice) this small, subjective audible snag.

CONCLUSION

Even if the cost were far higher, this speaker’s depth of expertise across the board would still be astounding. Q Acoustics can be proud of its ability to maintain transparency, detail, and auditory definition while essentially redefining expectations for the price, allowing you to focus just on enjoying all the music.

With the Concept 500, Q Acoustics has proven that a detailed understanding of the principles of acoustical design and their skilled implementation in real-world situations can lead to exceptional outcomes without utilizing exorbitantly expensive resources.

If you’re looking to invest approximately $6500 on a floor stander, it ought to rank at the top of any shortlist of loudspeakers that you may currently be investigating. Be aware that for the most discerning listeners, careful placement and associated equipment is mandatory to squeeze out every last drop of goodness from the speaker. In that sense, music and audio enthusiasts who desire accurate yet passionate reproduction of recordings from a wide range of genres will be captivated by the Concept 500. It is a superlative product!

Review system: Loudspeakers: QLN ONE Loudspeakers~ Harbeth Compact 7ES-3 XD loudspeaker ~ Quad ESL 63 ~ Digital: Mojo Audio ‘Mystique’ X DAC ~ Innuos Zenith Mk.3 server/streamer ~ Audio Note (UK) CD3.1x/2 player/DAC Analog: Audio Technica LP-7/ZYX Bloom 3 mc cartridge Amplification: ~Pass Labs XP-12 preamp, Pass Labs XA30.8 power amp ~PS Audio M1200 ~Allnic Audio A-2000 25^th Anniversary SE amplifier ~ Cables/ Conditioners: Argent/Pur Silver stranded loudspeaker cables / Inakustik AC-3500p power station &, AC-2404 reference Air Power Cord ~ Audience Studio 1 interconnects,~ Clarus “Crimson” 75-ohm digital spdif / Audio Art 1 e” AC Power Cord