ONKYO Scepter 200
¥ 198,000 (1 unit, around 1982)
Commentary
A sound field type speaker system with a rear radiator to compensate for the indirect sound component of the band that is insufficient for ordinary speakers.
In a normal 3-way system, the sound energy imbalance caused by the directional characteristics of the unit causes the sound pressure frequency characteristics on the axis to be flat, but the energy response shows a pattern of large undulations around the crossover frequency, and decreases as the frequency goes higher.
To compensate for this unevenness in acoustic energy and to keep the ratio of direct and indirect sound constant over the whole fractional band, rear radiators are installed on the top and back of the enclosure. This rear radiator consists of three ways to compensate for the high range energy of each front unit.
A 38 cm cone type woofer using Delta Olefin Refined Corn is installed in the low range.
Delta Olefin Refined Corn is an improved version of conventional Delta Olefin. While maintaining the ideal internal loss, which is the greatest feature of Delta Olefin, the rigidity is enhanced by increasing Young's modulus by four times by controlling the added compound.
In addition, a large magnet of 160 φ x85 φ x20tmm and a 4-layer long voice coil of 76 mm diameter are used for the magnetic circuit, and a butterfly damper made of glass-reinforced polyimide resin with excellent linearity is used for the damper.
The middle section is equipped with a composite unit combining magnesium alloy and 10 cm cone.
The diaphragm part uses a composite diaphragm composed of a magnesium alloy diaphragm of 65 φ mm and 100 μ m thick and a 10 cm cone for both weight reduction and high rigidity. The composite diaphragm structure also stabilizes the suspension system such as weight reduction of the diaphragm and two point support.
The magnetic circuit uses a strong magnet of 140 φ x75 φ x1tmm, magnetic flux density 12,000 gauss, total magnetic flux 127,000 maxwell, and the voice coil uses a 65 φ mm voice coil.
The edge has a special double support structure that supports the magnesium alloy diaphragm and cone, respectively.
This mid-range unit has a back cavity with a capacity of 0.7l and a minimum resonance frequency of 240 Hz.
A 2.5 cm dome type tweeter is installed in the high range.
The diaphragm uses a newly developed plastic vapor deposition method and a newly developed 40 μ m magnesium alloy diaphragm with a uniform coating as thin as 6 μ m. In addition, the foam rubber for braking, which had been strapping inside the dome part in order to suppress high-frequency resonance in the past, is removed, and efficiency is improved by 4-5 dB and wide-band characteristics up to 45 kHz are obtained.
In addition to the use of a strong magnet, the magnetic circuit has a shape that makes it easy for the plate magnetic flux to concentrate. In addition, a magnetic fluid is injected into the gap, so that all the magnetic flux is concentrated in the voice coil.
Furthermore, by adopting an equalizer based on computer analysis, we have improved the energy and directional characteristics between 10 kHz and 15 kHz.
The Low-Mid radiator, which compensates for sound energy in the high-frequency range of the woofer, employs a 10 cm cone unit of a delta olefin diaphragm.
The Mid-High radiator uses two 7 cm cone units and is fixed to a frame at an angle of 30 ° to the baffle surface.
The Super High radiator uses a ring-shaped diaphragm driven by a 35 mm diameter voice coil in combination with a conical horn with a three dimensional rotation angle of 90 °.
.JPG)
Model Rating
| Method | 6-way, 7-speaker, sound field type bass reflex system ・ Bookshelf type |
| Units Used | For low band : 38 cm cone type For Middle Area : 10 cm Composite Type For high-pass : 2.5 cm dome type Rear Radiator 10 cm delta olefin cone type 2 x 7 cm cone shapes Ring radiator |
| Playback frequency band | 23 Hz to 45 kHz |
| Max Input | 150W |
| Instantaneous maximum input | 1,500W |
| Impedance | 6 Ω |
| Output sound pressure | 91dB/W/m |
| Crossover frequency | 450 Hz, 3.5 kHz |
| Level control | Skoka tweeter and each rear radiator independent type |
| Internal volume | 103L |
| External dimensions | Width 486x Height 790x Depth 430 mm |
| Weight | 42kg |