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Pioneer SE-405 Stereo Headphones
A new addition to Pioneer's growing line of stereo headphones is the Model SE-405, which features full-size acoustically isolating earcups and integral volume controls for each channel. Cushions for the earcups and the extendable (with detented action) headband are foam filled plastic; the cups and headband are linked by pivoted yokes. An 8-ohm dynamic element with a 13/4-inch polyester-film diaphragm is used in each earcup.
Frequency range is stated as 20 to 20,000 Hz. Sensitivity is 0.3 volt for a sound-pressure level of 113 dB, and signal-handling capability is 0.5 watt. The coiled connecting cable, 161/2 feet long, is fitted with a standard three-conductor phone plug. Exclusive of the cable, the headphones weigh just over one pound.
Price: $44.95, which includes a permanent storage case.
Bostedt "Superbend" Speaker Systems
INTERNT’L ENTERPRISES COMPANY is importing the Swedish made Bostedt "Superbend" speaker sys tem, a two-way design of markedly distinctive appearance, utilizing an enclosure molded of high-impact plastic. The two drivers-a 5-inch mid-range/woofer (approximately the same diameter as the stovepipe-shaped enclosure) and a 1.5-inch tweeter-radiate horizontally from behind an anodized wire-mesh grille.
According to the manufacturer, the balance of high frequencies to low frequencies can be altered by aiming the speaker toward or away from the listening area.
Frequency response is 65 to 14,000 Hz ±3 dB, with a 12-dB-per-octave cross over network dividing the frequency band between the two drivers at 1,800 Hz. Nominal impedance is 8 ohms, and minimum recommended amplifier power is 15 watts per channel. Power-handling capability is 35 watts per channel continuous. The Superbend is available in glossy colors of white, black, and red-all with a black grille. The overall dimensions are 12 x 7 1/4 x 6 1/4 inches. Price: $125.
Teac Model 360S Stereo Cassette Deck
THE Model 360S, the latest cassette deck from Teac, has a transport mechanism with performance comparable to that of Teac's deluxe Model 450 as well as many of the operating features of the more expensive machine. Dolby B-Type noise-reduction circuitry is incorporated. with all calibration controls accessible to the user. Bias and equalization are switchable for CrO2 "high-performance," and standard tapes. In the CrO2 position the playback equalization is also altered to the values recently proposed for that tape type. Two large recording level meters are supplemented by a peak indicator- a light-emitting diode that warns against overload on short-term transients. Slider-type recording- and playback-level controls are used. There is a switchable multiplex filter to remove the 19-kHz pilot signal from stereo FM broadcasts, and a memory-rewind feature that automatically stops the tape at a point preselected on the three-digit index counter.
With CrO2 tape, the frequency response of the 360S is 40 to 15,000 Hz +- 3 dB. Response is within the same tolerances to 13.000 Hz with high-performance tape, and to 10.000 Hz with standard tape. Signal-to-noise ratios are 60 dB with Dolby, 50 dB without. Wow and flutter are 0.07 percent. The micro phone inputs have an impedance of 600 ohms; adjacent to them is a stereo head phone jack. that will drive 8-ohm phones.
The Teac 360S comes mounted on a wood base; dimensions are 17 3/4 x 4 3/4 x 10 1/4 inches. Price: $359.50.
Soundcraftsmen PE2217 Stereo Preamp-Equalizer
HAVING offered elaborate one- and two-channel multi-band equalizers for some years, Soundcraftsmen has now added signal-switching and magnetic phono-input facilities to their ten-band stereo equalizer to create the Model PE2217 Preamp-Equalizer, a unit de signed to function as a highly flexible integrated control center for a two-channel stereo system. While VOLUME and BALANCE are conventional knob adjustments, all the frequency-related functions of a typical preamplifier-bass and treble adjustment, filters, loudness compensation-are handled in the PE2217 by the equalizers. The equalizers have ten slider-type controls for each channel spanning a range of ±12 dB, acting at the center frequencies of the ten octaves of the audio-frequency band. Gain-control sliders adjust the output levels of the equalizers; LED (light-emitting diode) indicators permit the equalizers to be set for unity gain to facilitate A-B comparisons with the unequalized signals and to prevent overload of subsequent stages.
The remaining PE22 17 controls are all pushbuttons. They activate the I.ED indicators, select reversed stereo, left or right channel to both outputs, or mono, and operate tape-monitoring functions for two stereo tape decks, permitting dubbing from either one to the other.
The inputs for two magnetic-phono sources, tuner, and auxiliary are also pushbutton-selected. The equalizers can be switched to affect only the "to tape" signals, the preamplifier output signals, or both. There are tape-dubbing jacks and two stereo headphone jacks on the front panel, and two sets of outputs and six a.c. convenience outlets on the rear panel. The rated output of the PE2217 is approximately 5 volts for load impedances ranging from 600 to 2,000 ohms, with harmonic and intermodulation distortions of less than 0.02 percent. Signal-to-noise ratios are 80 dB for the phono inputs, 95 dB for high-level in puts. Frequency response with the sliders centered is 10 to 100,000 Hz-0.25 dB. The preamplifier measures 20 x 7 1/4 x 11 3/4 inches. Price: $499.50, which includes a walnut-grain cabinet or optional hardware for rack mounting of the unit.
Sanyo RD 4350 Dolby Stereo Cassette Deck
THE top model in Sanyo's growing line of Dolbyized stereo cassette decks is the Model RD 4350, equipped with a ferrite record/playback head, a memory-rewind feature that halts the transport at any preselected point on the tape, and a novel tilt-up instrument panel that cants the recording-level meters for easier viewing. Seven piano-type push keys, including CUE, PAUSE, and a wide push bar for STOP, operate the transport. Separate level controls are provided for re cording and playback, and there are switches to select NORMAL Or SPECIAL tape-type characteristics, recording through microphone or line inputs, and to activate the Dolby circuits. At the end of a tape the transport automatically shuts off and disengages completely.
Specifications include a record-playback frequency response of 40 to 15,000 Hz ±3 dB, a signal-to-noise ratio of 50 dB, and wow and flutter of less than 0.15 percent. Transport speed accuracy is at least 99.8 percent. Dimensions of the deck, including its wood base, are 17 x 9 x 5 inches. It weighs 12 pounds. Price: $329.95.
Telephonics TEL-111 Electret Stereo Headphones
MAKING its first entry into the con sumer audio market, Telephonics has introduced a line of stereo and four-channel headphones featuring the Model TEL-111, a stereo headset that employs the electret-condenser principle. Electret transducers closely resemble conventional electrostatic designs, except that the membranous diaphragm is permanently polarized with an electrical charge, eliminating the need for an external power supply to develop the required bias voltage. In each earpiece the Model TEL-111 has a 2 1/2-inch, push-pull diaphragm that has been clamped to form two radiating surfaces- a small circular one for the higher frequencies and a larger crescent-shaped area for lows. The phones are driven from the speaker terminals of an amplifier or receiver through step-up transformers installed in an external control box to which the headphones and the speakers are connected. A switch selects either source.
The TEL-111 has ring-shaped foam filled cushions designed to isolate the wearer from external sound. The head band is padded, and attaches to the ear pieces through sliding length adjustments for custom fit to the individual wearer. The frequency range of the phones is said to be 18 to 24,000 Hz, arid total harmonic distortion does not exceed 0.2 percent for a sound-pressure level of 115 dB. An input of 2.4 volts at the transformer drives the phones to a level of 104 dB ±3 dB at 1,000 Hz. The headset weighs 17 ounces exclusive of cable and control box. Price: $87.50.
Avid Series 100 Speaker Systems
THE first consumer products from the Avid Corporation are three speaker systems of the air-suspension type, featuring simple, attractive styling and user-replaceable grille cloths. At the top of the line is the Model 103 ($139.50; shown), incorporating a 10-inch woofer, 4 1/2-inch cone-type mid-range, and a 1-inch dome tweeter. The Model 102 ($109.50) is a two-way system employing the woofer and the tweeter from the Model 103; the Model 100 ($79.50) has an 8-inch woofer and a 1 3/4-inch cone tweeter. All the systems have a nominal impedance of 8 ohms and level controls to adjust high-frequency output to suit the room acoustics. (The Models 100 and 102 have three-position switches; the Model 103 has a five-position switch, with the central three positions affecting only high frequencies and the extreme settings altering both mid- and high-frequency levels.)
Frequency responses are 35 to 18,000 Hz (40 to 18,000 Hz for the Model 100) ±5 dB.
The Model 103 has crossover frequencies of 500 and 3,500 Hz; the two less expensive systems are crossed over in the region of 2,500 Hz. Power-handling capabilities range from 75 watts (Model 100) to 150 watts (Model 103). The systems are said to be somewhat more efficient than the usual air-suspension de signs, with 1-watt white-noise inputs producing sound levels of 83 to 86 dB at a three-foot distance. The mid-and high-frequency drivers of the Models 103 and 102 are fused as a safeguard against amplifier overdrive.
The grille cloths of the Avid speaker systems can be removed from the front of the enclosures-and from the frames on which they are stretched-for washing or replacement with a fabric of the owner's choice. Avid offers pre-cut re placement grille cloths in eight optional colors ($3.95 per pair). The enclosures, clad in walnut-grain vinyl, measure about 25 x 15 x 9 1/2 inches for the Models 103 and 102, and 12 3/4 x 21 x 8 1/2 inches for the Model 100. Low wooden bases for floor placement are included in the price of the Model 103; they are optional for the Model 102 at $3.95 each.
Prices are slightly higher in the West.
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EDITORIALLY SPEAKING, WILLIAM ANDERSON