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The Revel Concerta F12's voltage sensitivity was both to specification and higher than average at 90dB(B)/2.83V/m. Its impedance remained between 4 and 8 ohms over most of the audioband (fig.1), but did drop to 2.9 ohms in the low treble. This, together with the combination of 5.2 ohms and –45° electrical phase angle at 90Hz, means that a good amplifier rated at 4 ohms will be required to drive the F12 to high levels.

Fig.1 Revel Concerta F12, electrical impedance (solid) and phase (dashed). (2 ohms/vertical div.)

A small glitch just below…

The loudspeakers I heard that day sounded very dynamic, delivering the frequency extremes with definition and…

Setup is greatly enhanced by the Mach 17's modular design—the system can be unpacked, set up, moved, placed, and assembled by one mere…

Description: Three-way, tri-amped floorstanding dynamic loudspeaker. Drive-units: one 1" (25mm) silk-dome tweeter, one 6" (150mm) vacuum-formed TPX-cone midrange with vented pole-piece phase plug, two reflex-loaded, 12", treated paper-cone woofers. Crossover frequencies: 325Hz, 1850Hz. Frequency response: 27Hz–20kHz ±1dB. Sensitivity: 91.5–94dB/2.83V/1m. Nominal impedance: 8 ohms, tweeter and midrange sections; 4 ohms, woofer section. External electronic crossover: fully balanced (inputs and outputs), stereo, three-way, with three level controls and a mute…

Listening tests were carried out in my main listening area—a spacious, 5500ft3 room with an effective length of 51', a width of 13', and a height of 12', in a wood-frame house with only moderate masonry infill. The room has only one area rug, making it a live listening environment, while its generous length supports low bass, with reinforcement from the side and back walls. Previous reviews describe this large room's construction, exact dimensions, contents, listening positions, rugs, windows, reverberant character, and bass modes (see March 1992, Vol.15 No.3…

The Waveform Mach 17 is indeed very sensitive, with 2.83V of noise raising a sound-pressure level of 93.5dB/W/m at 1m. Figs.1–3 show the electrical impedance curves for the woofers, midrange, and tweeter respectively. Note that these are wideband curves, but in fact the partnering amplifiers will only see that portion of each drive-unit's impedance in its passband. The woofer curve, for example, shows some cabinet resonance-related spikes in the upper midrange, but these will not be excited in normal use. While the midrange is basically an 8 ohm device, the…

Armed with a background in mechanical engineering studies at both RPI and Northeastern, and work experience that included high-energy laser and aerospace (missile and helicopter) R&D, Conti set about designing his dream 'table. Once he was…

Description: Belt-drive turntable with fluid-damped spring suspension. Speeds: 331/3rpm, 45rpm. Rumble, wow & flutter: not specified.
Dimensions: 22½" W by 7¼" H by 16" D. Weight: 90 lbs.
Serial number of unit reviewed: 991708.
Price: $8200, $10,600 with vacuum holddown platter (2000). Basis record clamp: $250. Approximate number of dealers: 60.
Manufacturer: Basis Audio, 26 Clinton Drive, Unit 116, Hollis, NH 03049. Tel: (603) 889 4776. Fax: (603) 889-5402. Web: www.basisaudio.com.

Analog source: Simon Yorke turntable; Graham 2.0, Immedia RPM tonearms; Crown Jewel SE, EMT TU-2, Grado Statement, Lyra Parnassus D.C.t, Transfiguration Temper Supreme cartridges.
Preamplification: Ayre K-1 preamplifier, Audio Research Reference phono section.
Power amplifiers: Musical Fidelity Nu-Vista 300, KR Enterprise VT8000 MK monoblocks.
Loudspeakers: Audio Physic Virgo, Sonus Faber Amati Homage.
Cables: Interconnects: Yamamura Millennium 6000, Musical Fidelity Nu-Vista, Electra Glide. Speaker cables: Yamamura Millennium 6000, QED Silver…