John Atkinson performed the measurements on the NHT 3.3, handing me the file only after I had finished my auditioning. Its B-weighted sensitivity measured approximately 87dB/W/m (B-weighted). Its impedance (fig.1) is quite uniform, both in magnitude and phase angle, verifying NHT's specifications and indicating that the 3.3 will be a relatively easy load to drive. The maximum value of just over 10 ohms at 27Hz indicates the low-frequency tuning point of the system—an unusually low value. This is the -6dB point of the woofer's near-field response (see fig.2). The…
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Sidebar 2: Specifications
Description: Four-way, sealed-enclosure, loudspeaker system. Drive-units: 12" polymer-cone woofer, 6.5" polymer-cone midbass, 4" polymer-cone upper midrange, 1" fluid-damped aluminum-dome tweeter. Crossover frequencies: 100Hz (12dB/octave), 320Hz (12dB/octave), 3.5kHz (18dB/octave). Frequency response: 23Hz-26kHz ±2dB (in-room, 1m). Usable bass response: -6dB at 19Hz, in-room (-3dB at 22Hz, in-room). Sensitivity: 87dB/2.83V/1m. Nominal impedance: 6 ohms (4.3 ohms minimum, 10.5 ohms maximum, no phase angle greater than ±30 degrees). Amplifier requirements: 30-…
Harry Partch (1901-1974), composer and inventor of musical instruments, delighted in generating deep bass. Finding most standard orchestral instruments wanting in that department, he built the huge Marimba Eroica, which he described on his A Glimpse into the World of Harry Partch: 27 Unique Instruments (LP, Columbia MS-20576):
"In the right room acoustically, the Eroica is felt through the feet, against the belly, and, if one sits on the floor, it ripples through his bottom. It is very difficult to put on tape, and especially on records, with any fidelity. Adequate playback equipment is…
This was proven time and again. Track 7 of the Patriot Games soundtrack (CD, RCA 66051-2), "Assault on Ryan's House," is a torture test for subs as it contains an overabundance of unusually thick bottom-end information. But the EMB-1200 was unperturbed and uncovered quite a bit of music down there, which added immeasurably to the realism of the sound. The EMB-1200 played the passage with no sign of distortion or stress. The bass remained clean, deep, and solid, with no spurious noises to indicate that the woofer was in difficulty.
The EMB's speed and agility rendered dynamics with…
Sidebar 1: Specifications
Description: Powered bandpass subwoofer in sealed enclosure with signal-sensing auto on/off. Drive-units: 12" long-excursion, cone driver with 3" push-pull voice-coil and 15-lb magnet, 12" brushed-aluminum-cone passive radiator. Frequency response: 20-150Hz, ±3dB. Low-pass filter: 40-150Hz (variable, defeatable), 24dB/octave slope. No high-pass filter. Total harmonic distortion: <0.5%. Amplifier: 1200W RMS, 3600W peak (class-D). Inputs per channel: 2 line-level (RCA), 2 high-level. Speaker terminals: 4 (bare wire, banana plugs, or spade lugs). Outputs: 2 line…
Sidebar 2: Associated Equipment
Analog source: Linn Sondek-Lingo turntable, Linn Ittok tonearm, Spectral moving-coil cartridge.
Digital sources: Krell KRC-28 CD player, Sony SCD-C555ES multichannel SACD/CD player.
FM tuners: Day-Sequerra Classic, McIntosh MR-78, Sony ST-5000.
Preamplification: Mark Levinson ML-7 preamplifier with L3A moving-coil phono cards, Duntech MX-10 head amplifier, Margulis phono section, Krell KCT preamplifier.
Power amplifiers: Mark Levinson ML-2 monoblocks, Mark Levinson No.334, Krell FPB 600c.
Loudspeakers: Quad ESL-989, Velodyne DD-18 subwoofer…
Sidebar 3: The James EMB-1000 subwoofer
The 10" EMB-1000 ($1595) shares the larger EMB-1200's design and internal amplifier, but it costs $600 less. It's also 1" shorter and thinner, 4" shallower, and weighs 30 lbs less. The EMB-1000 (serial number 1577) performed surprisingly well in my large listening room with most program material. To my surprise, I was able to blend it with the Quad ESL-989s at 45Hz, which made it much less directional than the EMB-1200. Working behind the Quads, it widened and deepened the soundstage even more.
However, demanding program material showed its…
"Be careful what you wish for, or you just might get it."
My mother's words echoed in my ears as I unboxed Classé Audio's CAM 350 monoblock amplifiers, and I couldn't help but smile. I've been using Magnepan loudspeakers on and off for the past 20 years, most often matching them with tube amps—VTL, for example, or perhaps VAC, Sonic Frontiers, or Audio Research. As good as these systems have been, what I always inevitably found myself wishing for was "a really good, big solid-state amp."
Aladdin's Lamp?
At 350W—or 700W into the Magnepan 3.6/R's 4 ohm load—I figured the…
Is there a Genie in the Lamp?
The CAM 350s arrived midway through my August 2000 review of the Magnepan MG3.6/R loudspeaker and immediately took up residence in my main system.
The CAM 350s arrived midway through my August 2000 review of the Magnepan MG3.6/R loudspeaker and immediately took up residence in my main system.
Over the years, in daydreams in which I'd mentally paired Magnepans with my dream amp, the most dramatic effects were significant improvements in transparency, dynamics, and the resolution of low-level detail. In my musings, that last little bit of gauze that my Maggies could never seem to shake would simply vaporize. The tiniest details would be revealed, imbuing images with a vibrant life and body. Subtle…
Parts List
Potentiometers:
VR1: Your choice of ALPS "Black Beauty" 100k stereo audio taper pot, Penny & Giles RF15-2-20k-A 20k stereo audio taper pot or ALPS "Budget Gourmet" 100k stereo audio taper pot (Radio Shack part #271-1732).
VR2 & 3: Bourns 3386-OT1 5k sealed cermet miniature trimpot.
Buffers:
IC1 & 2: PMI BUF-03AJ milspec version. (The impecunious can experiment with the less-expensive BUF-03J and -EJ commercial versions, which have reduced slew rates and drive capabilities, but these have not been auditioned.)
Switches:
SW1 & 2…