Design
The Concept 300 costs $4499.99/pair, including a pair of unique stands: skeletal, 26"-tall Tensegrity…
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When I performed the measurements of the Q Acoustics Concept 500 loudspeaker to accompany Thomas J. Norton's review in March 2019, I was impressed by what I found. The floorstanding Concept 500 offers a high level of audio engineering excellence for its price of $5999.99/pair. When I attended a Q Acoustics press briefing a few months back, where the English company announced the US availability of their stand-mounted Concept 300, I didn't hesitate to ask for a pair to review.
Low-level detail in the sound of the piano was well-preserved by the Concept 300s, even when Jarrett was comping at high levels with his left hand. I followed "Kyoto" with The Carnegie Concert (16/44.1k ALAC files, ripped from CD, ECM 07362), for which I had been in the audience back in 2005. Whereas the Sun Bear improvisations are unbroken stretches, sometimes lasting more than 40 minutes, Carnegie comprises shorter pieces, more akin, dare I say it, to songs. The image of the piano is wider and closer than it is on "Kyoto," and the instrument has more low-frequency power. Again, the Concept…
Sidebar 1: A Sprung Suspension on a Loudspeaker?
After I attended the launch event for the Q Acoustics Concept 300 with John Atkinson, I found myself interested in this speaker's unique stands—which, as JA points out in his review, incorporate a sprung, low-pass vibration filter to isolate the speaker from its surroundings, much as a suspended turntable isolates the platter from floor-borne vibrations.
It's an interesting idea—especially in the context of a dynamic loudspeaker, which has drivers moving in and out over a wide range of frequencies. When a driver cone moves, its…
Sidebar 2: Specifications
Description: Two-way, stand-mounted, reflex-loaded loudspeaker. Drive-units: 1.1" (28mm) fabric-dome tweeter, 6.5" (165mm) coated paper-cone woofer. Crossover frequency: 2.5kHz. Frequency response: 55Hz–30kHz, +3dB, –6dB. Nominal impedance: 6 ohms. Minimum impedance: 3.7 ohms. Sensitivity: 84dB/W/m. Recommended power: 25–200W.
Dimensions: Loudspeaker: 14" (355mm) H × 8.6" (220mm) W × 15.7" (400mm) D. Effective internal volume: 11.4 liters. Weight: 31.9lb (14.5kg) each. Shipping weight: 36.3lb (16.5kg) each. Tensegrity stand: 27.2" (690mm) H × 18.1" (460mm) W…
Sidebar 3: Associated Equipment
Analog source: Linn Sondek LP12 turntable with Lingo power supply, Linn Ekos tonearm, Linn Arkiv B cartridge, Channel D Seta L phono preamplifier.
Digital sources: Roon Nucleus+ file server; Ayre Acoustics C-5xeMP universal player; PS Audio PerfectWave DirectStream D/A converter.
Power amplifiers: Lamm Industries M1.2 Reference, Vandersteen M5-HPA (both monoblocks).
Integrated amplifier: NAD M10.
Loudspeakers: KEF LS50.
Cables: Digital: AudioQuest Vodka (Ethernet), DH Labs (1m, AES/EBU). Interconnect: AudioQuest Wild Blue (balanced,…
Sidebar 4: Measurements
I used DRA Labs' MLSSA system and a calibrated DPA 4006 microphone to measure the Q Acoustics Concept 300's frequency response in the farfield, and an Earthworks QTC-40 mike for the nearfield and in-room responses.
Q Acoustics specifies the Concept 300's sensitivity as 84dB/W/m. My estimate was slightly higher, at 86dB(B)/2.83V/m. The Concept 300's impedance is specified as 6 ohms, with a minimum value of 3.7 ohms (on the website) or 4.7 ohms (in the product's white paper). My impedance measurements, which I took with MLSSA then checked with Dayton Audio's…
In the November 1994 issue of Stereophile, Robert Harley reviewed three products that were intended to reduce word-clock jitter in an S/PDIF or AES/EBU serial datastream: the Audio Alchemy DTI Pro, the Digital Domain VSP, and the Sonic Frontiers UltrajitterBug. (All three handle 16-bit data sampled at rates of 44.1kHz and 48kHz.) This review was published before Paul Miller and the late Julian Dunn created the J-Test signal, which combines a high-level tone at exactly one quarter the sample rate (Fs/4) with a low-level squarewave at 1/192 the sample rate produced by toggling the LSB. (This…
Of the celebrated triumvirate of John Scofield, Pat Metheny, and Bill Frisell—the most original and influential jazz guitarists of the past 50 years—none is more distinctive, or self-effacing, than Frisell, a true changeling of the guitar. Frisell is a jazz-based musician, but his music crisscrosses genres, and his guitar playing isn't bound to or limited by a specific technique. He's a master illusionist, able to alter a song's meaning far beyond its original intent with the aid of a Telecaster guitar, a modest effects chain, and, most importantly, his rich imagination. In concert—as I…
Tell me now: When you're there in the scene, watching Lord Voldemort chase Han Solo through the Cave of the Klan Bear, how often do you notice that the sounds you're experiencing are being pumped at you from five black-painted room boundaries, while the flickering-light images approach from only one? Moreover, in a parallel, more quotidian reality, you're sitting upright in your seat, noisily chomping popcorn while absorbing—and processing—massive amounts of sensory data: Did you ever consider the sensual, mechanical, and psychological complexity of a moment like this, and how fundamentally…
"Since the amplifier damping factor plays no role and the cables need to be terminated with more than 2 ohms, then we can use a resistor of any convenient value connected in series to the headphones and their cable. As far as the ribbon is concerned, this is a current-source operation mode.
"The RAAL specs say: Impedance: 0.018 ohms; Sensitivity: 85dB/1mW; Power Handling With Bass-Heavy Tracks: 450mW RMS; Max SPL at 450mW RMS (limited by ribbon excursion at LF): 111dB.
"To develop 450mW of power at 0.018 ohms load, we need 5 amps RMS."
Listening with the Schiit Aegir
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