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The impedance curve (fig.1) shows the double hump at low frequencies typical of a reflex design; the "saddle" between these two humps at about 29Hz (and just over 5 ohms) is the tuned frequency of the M-3si's ports. The overall impedance indicates a fairly easy load to drive, dipping just below 4 ohms only once, at just under 100Hz. The sharp peak just above 20kHz probably indicates the presence of a notch filter to tame a tweeter resonance.

Fig.1 Mirage M-3si, electrical impedance (solid) and phase (dashed) (2 ohms/vertical div.).

The…

Time and time again I get letters from readers who have relatively small rooms asking why they can't get an even tonal balance from their [insert brand-name of massive, flat-to-20Hz behemoth here] speakers.

The answer is a no-brainer: If you have only…

Description: Two-way, reflex-loaded, stand-mounted loudspeaker. Drive-units: 1" (25mm) metal-dome tweeter, two 4.5" (110mm) metal-cone woofers. Measured crossover frequency: 4kHz. Crossover slopes: first-order, 6dB/octave. Frequency response: 65Hz–18kHz ±2.5dB, 50Hz–22kHz ±4dB. Sensitivity: 91dB/W/m (2.83V). Nominal impedance: 8 ohms. Amplifier requirements: up to 250W. Harmonic distortion (no frequency specified): less than 0.05% of second and third harmonic at 90dB at 1m; less than 0.1% of second and third harmonic at 100dB at 1m. Power compression factor:…

The loudspeakers under test were positioned for the best sound (with only one pair of loudspeakers in the listening room at a time), generally some 3' from the rear wall (which is faced with books and LPs) and approximately 5' from the side walls (which also have bookshelves covering some of their surfaces). Each pair of speakers sat on their dedicated stands, these spiked to the concrete floor beneath the rug/pad, and was driven by the magazine-owned pair of Mark Levinson No.20.6 monoblocks, a Mark Levinson No.333 dual-mono amplifier, or a Cary Audio Design CAD…

As I found with the single-ended Cary, the Acoustic Energy will play reasonably loud with only a few amplifier watts, reaching spls in the mid-90s without discomfort: I estimated its B-weighted sensitivity as 88dB/W/m (footnote 1), but this figure is compromised by the frequency response on the tweeter axis (see later). With an impedance magnitude that drops to 4.3 ohms in the lower midrange but stays above 6 ohms over almost all the rest of the audioband, the AE2 Signature is a relatively easy load for an amplifier to drive (fig.1). The double peak in the bass is…

There are three new models, each using samarium-cobalt magnets with a healthy 600µV output: the Standard (Red), the Rosewood Signature, and the Urushi—$2500, $3500, and $4000, respectively. The Urushi was reviewed in the October '98 Stereophile by Michael Fremer; its aluminum lacquer-coated shell leaves some enthusiasts drooling on their tonearms. The Rosewood…

Description: Low-output, moving-coil phono cartridge. Stylus: specially designed and ground for Koetsu. Output: 200µV (1kHz, 5cm/s). Internal impedance: 5 ohms. Frequency range: 20Hz–100kHz. Channel separation: >30dB/1kHz. Channel balance: within 0.5dB/1kHz. Recommended VTF: 1.8–2.0gm. Recommended loading: 5–100k ohms. Compliance: medium-low. Recommended tonearm: medium-high mass.
Price: $5500. Approximate number of dealers: 30.
Manufacturer: Koetsu, Kyoto, Japan. Distributor: Musical Surroundings, Inc., 5856 College Avenue, Suite 146, Oakland, CA…

Turntables were my Forsell Air Force One and the La Luce/SpJ 'table and arm from Holland. Other cartridges on hand were the van den Hul Grasshopper IV GLA and Black Beauty, the Clearaudio Insider, and the Win SMC-10 and transformer.

Preamps included the Nagra PL-P and the YBA Signature 6 Chassis, plus the Expressive Technology SU-1 MC Step-Up transformer. Amplifiers in play were the Boulder 2050s, the YBA Passion monoblocks, and Forsell's The Statement. Speakers were our JMlab Utopias, optimized with Argent RoomLenses and ASC Studio Traps.

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Rotel's philosophy of audio design is consistent with my own taste as a reviewer. As explained in Rotel's US dealer training manual (143 pages, with multiple-choice review questions at the conclusion of each chapter), the company's focus…

Description: Solid-state stereo power amplifier. Output: 200Wpc into 8 ohms (23dBW), 300Wpc into 4 ohms (21.8dBW). Frequency response: <10Hz–100kHz, ±1dB. Damping factor: >500. Total harmonic distortion: <0.03%. Intermodulation distortion: <0.03%. Signal/noise ratio: 120dB.
Dimensions: 17" W by 5" H by 15" D. Weight: 37 lbs.
Price: $999 (1999); no longer available (2007). Approximate number of dealers: 200.
Serial number of unit reviewed: 748 136040.
Manufacturer: Rotel of America, 54 Concord Street, North Reading, MA 01864. Tel: (978)…