Roundup of the latest audio equipment and accessories.
Flat Woofers in Phase Technology Loudspeakers
Phase Technology's line of loudspeakers employs 6- and 10-inch woofers with solid high -density expanded -polystyrene flat pistons. The manufacturer states that the acoustic centers of all the drivers in a sys tem are aligned at the front surface of the enclosure to aid in phase alignment of the speaker's output.
The top model in the series, the PC-100 (right), is a four-way phase-coherent sys tem with two 10 -inch solid -piston woofers, a 3-inch soft-dome midrange driver, a 1 1/2 -inch soft -dome upper -midrange unit, and a 1-inch soft-dome tweeter. Frequency range is 24 to 20,000 Hz, and recommended amplifier power is from 50 to 200 watts. The cabinet is solid walnut with walnut veneer. Dimensions are 14 x 42 1/2x 8 inches. Price: $550. Phase Technology Corp., Dept. SR, 101 North Park Street, East Orange, N.J. 07017.
The Dual C-844 cassette deck has a "Direct Load and Lock" system that eliminates the need for a door between the user and the cassette compartment; the cassette is slipped directly into place and can be re moved at any time, even when the tape is in motion. Photoelectric circuitry in the cassette compartment stops the transport when a cassette is grasped. The separate record and play heads are mounted in a combined housing. Dolby-B and -C noise -reduction systems operate during record and play back. Meters show the level of the equalized signal reaching the tape heads, and four peak -level LEDs show when each of four tape types has been overloaded.
In addition to the standard 1 1/2-ips cassette speed, the C-844 also offers 3 3/4-ips play and record for extended frequency response and improved signal-to-noise ratio. Rated response with all tape types is 20 to 24,000 Hz ±3 dB at the faster speed. An optional infrared remote control is available. Price: $700.
Floor-standing Speaker from Mirage Acoustics
Mirage Acoustics' SM-1, a two-way sys tem, has an optional stand that was part of the original design concept. The Model T-1 stand precisely positions the SM- I so that the floor acts as an acoustical extension of the speaker. The system's crossover is a first -order design rolling off at 6 dB per octave, since in the view of the manufacturer a crossover that rolls off any faster degrades both a speaker's time characteristics and its transient response. The tweeter employs a soft -textile dome surrounded by a felt ring.
This ring is claimed to reduce diffraction, improve imaging, and smooth the high frequencies. The woofer is made of filled poly propylene. Prices: SM-1 , $329; T-1, $29.95. Mirage Acoustics, Unit One, Dept. SR, 21 Progress Avenue, Scarborough, Ontario, Canada
Denon's "Class-A" Integrated Amplifier
The Denon PMS-950 is an 80 -watt -per -channel amplifier using "pure class-A circuitry" throughout. It has two moving -coil pre-preamps, two moving -magnet preamps, a separate record -out selector, and a headphone amplifier that is adjustable for different headphone impedances. Other features include bass and treble controls, a direct -couple switch, and switchable infrasonic and loudness filters. Harmonic distortion is 0.004 percent or less. Signal-to-noise ratios of 90, 74, and 108 dB, respectively, are specified for the moving -magnet phono stages, the moving -coil phono stages, and the auxiliary stage. RIAA equalization is within 0.2 dB of standard. The PMS-950 weighs about 35 pounds. Price: $995.
Ortofon's Improved Moving-coil Cartridge
The MC 10 Mk II moving -coil cartridge from Ortofon has the same "Wide Range Damping" system already incorporated in the MC 30 and MC 20 Mk II cartridges. The unit's low equivalent tip mass of 0.5 milligram results from the design of its cantilever and its small nude elliptical diamond stylus. Frequency response is given as 20 to 20,000 Hz ± 1.5 dB. Output voltage at 1,000 Hz with a 5-cm/sec groove velocity is 0.09 millivolt. The cartridge's internal impedance is 3 ohms. Recommended load impedance is at least 10 ohms, recommended tracking force 1.5 grams. Weight is 7 grams. Price: $195.
Celestion Industries' Three-way Loudspeaker
The Celestion Ditton 300 has a 1-inch dome tweeter, a 5 -inch cone midrange, and a 10 -inch woofer with a polyvinyl -chloride surround. Anechoic frequency response is given as 52 to 20,000 Hz ± 3 dB. Crossover frequencies are 650 and 4,500 Hz. Nominal impedance is 8 ohms; minimum amplifier power is 20 watts per channel. The Ditton's sensitivity is 87.5 dB sound -pressure level measured at 1 meter with a 1 -watt input. Dimensions are 24 3/4 x 13 1/4 x 10 1/4 inches; weight is 30 pounds. Price: $400.
Sanyo's Low-price, Full -feature Cassette Deck
Sanyo's PLUS series D56 cassette deck offers metal -tape capability, Dolby -B noise reduction circuits, full -logic soft -touch transport controls, and an automatic music -selection system (AMSS) that searches for pauses between recorded selections. Other features include two-color LED level indicators, a recording -mute control, timer/ standby switching, a headphone output, and two microphone inputs. Price: $239.95.
Catalog of Interference-reducing Equipment
Electronic Specialists' twenty-four -page catalog of power -line filters, protectors, and isolators also contains information on audio -interference filters for phono inputs and speaker lines. In addition to product descriptions, the catalog also offers suggested solutions for specific interference and noise problems. Request Catalog 801 from Electronic Specialists, Inc., Dept. SR, 171 South Main Street. Natick, Mass. 01760.
Acoustical Physics' Satellite Speakers
The Acoustic Image loudspeaker system is a satellite unit designed to be used with any available subwoofer. The manufacturer says that the speakers have optimized time-domain transient responses; their small size is said to minimize "time -domain dispersion" and "near-field time-delay distortion caused by diffraction effects." Frequency response is given as 60 to 22,000 Hz, impedance as 8 ohms. Power -handling capability is 40 watts when the speakers are used by themselves as a full-range system. The rating goes up to 200 watts when a pair is used with a 100 -Hz crossover to a subwoofer.
The driver complement includes a 1-inch soft -dome tweeter and a rubber -damped 5 inch mid-bass/midrange unit. Each enclosure measures 6 x 16 1/4 x 13 inches. There is no grille cloth. Stands shown are optional. Price: $500 per matched pair. Acoustical Physics Laboratories, Dept. SR, 135 16th Street, Atlanta, Ga. 30318.
Energy Loudspeaker's Model Four Has Isolated Woofer
The Model Four from Energy Loud speaker Corp. is a three-way floor-standing unit. The woofer chassis is mounted on an isolator that separates the front baffle from speaker-chassis vibrations and is said to eliminate a "boxy" sound quality in the 100- to 600-Hz region. A passive radiator handles the speaker's output from 15 to 50 Hz. The 24 -dB -per -octave crossover design, constructed with more than twenty-eight components per speaker, is said to eliminate radiation -lobe errors over a large listening area and to give a solid stereo image. The midrange driver is fluid cooled and has a polypropylene cone.
Overall frequency response is given as 26 to 22,500 Hz ±3 dB. System resonance is 26 Hz. Nominal impedance is 4 ohms; recommended amplifier power is from 30 to 300 watts per channel. Sensitivity is a 95 dB sound -pressure level at 1 meter with a 2.83 -volt input. Finish is oiled-walnut veneer. Dimensions are 41 1/2 x 17 1/4 x 14 1/2 inches. Price: $700. Energy Loudspeaker Corp., Dept. SR, 161 Don Park Road, Markham, Ontario, Canada L3R IC2.
Heco Tower Speaker Has Integral Subwoofer
The Heco Lab 3 is a live -way speaker system distributed by Osawa that has six 1-inch tweeters, four 2-inch midrange drivers, an 8 -inch woofer, an upward -firing 13-inch subwoofer, and a supertweeter. There are contour controls for super-high, high-, and middle frequencies, plus a bass -equalizer control. Frequency response is given as 20 to 40,000 Hz ± 2 dB. Sensitivity is 89 dB sound -pressure level at I meter with a 1 -watt input. Speaker impedance is switch able between 4 and 8 ohms. Recommended minimum amplifier power is 40 watts. Dimensions are 48 x 18 x 20 inches, weight 140 pounds. The driver positions are mirror-imaged for each pair of systems. Price: $2,450 each. Osawa & Co., Dept. SR, 21 Harbor Park Drive, Port Washington, N.Y. 10050.
NOTE: All product descriptions and specifications quoted in these columns are based on materials supplied by the manufacturers, who will respond directly to reader requests for further information.
Domestic inflation and fluctuations in the value of the dollar overseas affect the price of merchandise imported into this country.
Please be aware that prices quoted in this issue are therefore subject to change.
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Also see:
EQUIPMENT TEST REPORTS: Goldring G900E phono cartridge
Source: Stereo Review (USA magazine)