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Mesa Tigris integrated amplifier Measurements

Sidebar 3: Measurements

A complete set of measurements of the Mesa Tigris was made in the two-thirds pentode, Stage I feedback configuration. Additional selected measurements were made with other settings, but, unless noted otherwise, these results refer to operation in two-thirds pentode/Stage I.

The Mesa's voltage gain at maximum level measured 40.3dB. For the measurements I set the level control somewhat lower, at a position that produced 34dB gain (approximately 2:00 o'clock with Stage I feedback/two-thirds pentode). The amplifier's gain depends heavily, however, on its…

The Blind, the Double Blind, and the Not-So Blind

I was once in a sushi bar in Osaka; sitting next to me was a live abalone, stoically awaiting its fate. It stuck its siphon out of its shell, the waiter tapped the tip with a spoon, the siphon withdrew. Again the siphon appeared, again the waiter tapped it with a spoon, again it withdrew.

I was reminded of that abalone's blind persistence at Hi-Fi '94, Stereophile's recent High-End Hi-Fi Show in Miami, when the subject of blind listening tests once again raised its head in one of the "Ask the Editors" sessions (see Barry Willis's report on p.74).

Like Chuck Butler in this issue's…

The Blind, the Double Blind, and the Not-So Blind The 1991 AES Workshop on Data Compression

The AES Workshop on Data Compression, January 1992 (Vol.15 No.1)

The 91st Convention of the Audio Engineering Society held in New York on October 4–8 1991 had an unusual theme: "Audio Fact and Fantasy: Reckoning with the Realities." Although anti-audiophile expression occurs at every AES function, this was the first time an entire convention appeared to be devoted to it. The event seemed like a kind of showdown where the audio engineering establishment would once and for all discredit those who use their ears to judge reproduced audio quality.

However, I was encouraged by the tenor…

Conventional Wisdoms & Recommended Components

Conventional wisdom has it that the perfect sculpture is present, but hidden within the raw material. And the same conventional wisdom similarly applies to magazine editing: all it needs is careful chipping away at the extraneous material in the raw text files we receive from our authors—sometimes the barest degree of reshaping, repointing, and restructuring—and you have a finished product that both maximally communicates the writer's message and makes the anonymous artisan-editor proud of a job well done.

Perhaps it's because of the similarity between editing text and editing music that…

Fashions, Fads, & Single-Ended Amplifiers

As in any community bound tightly together by shared enthusiasms, the High End is regularly swept by tides of fashion. Some of the fads prove to be based on something of value, and outlast the initial burst: loudspeaker spikes and Tiptoes, for example, or the resurgence of tube designs, or making use of high-quality passive components. Other fads, particularly if not based on good engineering, fall by the wayside. (Does anyone still use a Tice Clock in their system? Or suspend their cables and interconnects on little acrylic bridges?)

Still other tweaks do seem to have a real effect on…

Phantom Acoustics Shadow active low-frequency acoustic control

The acoustic environment for music reproduction is easily the most overlooked source of sonic degradation. Many fine playback systems are compromised by room-induced anomalies that severely color the reproduced sound. When we live in a world of directional wire, high-end AC power cords, and $4000 CD transports, paying attention to the listening room's contribution to the musical experience takes on greater urgency.

Audiophilia's underestimation of a room's effect on musical fidelity can be traced to two causes: 1) the science of acoustics is quite mathematical and arcane, and 2) acoustic…

Phantom Acoustics Shadow active low-frequency acoustic control Page 2

This concept is far from new. Olson and May, in a 1953 Journal of the Acoustical Society of America paper, described a system called a "free field zone type sound reducer." It consisted of a microphone, amplifier, and loudspeaker set in a loop to define an acoustic region of low pressure. They further described mounting the device in the room corners to maximize its effect by presenting it with the large acoustic load present there.

When a room is pressurized by sound, the pressure is not evenly distributed throughout the room. Instead, high-pressure zones are created along most of the…

Phantom Acoustics Shadow active low-frequency acoustic control System

Sidebar 1: System

The playback system used to evaluate the Shadows consisted of Vortex Screen and TDL Reference Standard loudspeakers (the TDLs are reviewed in this issue), VTL 225W tube and Muse Model One Hundred Fifty monoblocks, Marantz CD-94 CD player, and AR turntable with an Ortofon MC-200 cartridge. The preamps were a Conrad-Johnson Premier Seven (phono) and a passive unit made by Electronic Visionary Systems (CD). Speaker cable was AudioQuest Clear, and interconnects were van den Hul and Solid Core Technologies ST-04. All AC power was supplied from a Tice Audio Titan/Powerblock…

Phantom Acoustics Shadow active low-frequency acoustic control Specifications

Sidebar 2: Specifications

Description: Floor-standing, active column for attenuating low-frequency resonances in listening rooms.
Dimensions: Column: 31" circumference (36.5" including base), 9.5" diameter (15" including base), 84" high; outboard power supply: 6.5" W by 2.25" H by 8.5" D, not including feet or rear-panel jacks.
Price: $2500/pair (1989); no longer available (2007). Approximate number of dealers: 60.
Manufacturer: Phantom Acoustics, distributed by InConcert, Auburn, CA (1989).

Boston Acoustics Lynnfield 500L loudspeaker

To many audiophiles, the name Boston Acoustics is synonymous with mass-market budget loudspeakers. Although many of its products have offered good value for the money, Boston Acoustics has never been known for driving the envelope of high-priced loudspeaker design (footnote 1). The company has been content to churn out well-designed, affordable boxes and let others attempt state-of-the-art loudspeakers. Until now.

In early 1991, Boston Acoustics began "The Lynnfield Project," an ambitious effort to develop a line of high-end loudspeakers that would push the edge of current loudspeaker…