CORAL DX-7
¥ 79,800 (1 unit, released in 1983)
Commentary
Based on the experience and know-how accumulated in the X Series, this bookshelf speaker system was developed as a speaker for the digital audio age.
A 31 cm cone type woofer is installed in the low range.
The diaphragm is made of cone paper blended with excellent Japanese and Northern European pulp and made into a three dimensional cross-linked structure with porous properties and thermosetting polymer treatment strengthening, and the mass / rigidity ratio has been improved by more than 50%.
In addition, it is equipped with a vibration system such as a high linearity damper and an edgewise wound voice coil (long stroke type) of oxygen-free copper ribbon wire and a 160 mm φ magnetic circuit.
A 9 cm hard dome type skoker is mounted in the middle area.
The diaphragm is made of newly developed ATMC super-hard light alloy. In order to increase the rigidity without increasing the weight, the inner and outer surfaces are surface-treated with a thick film of Hv500, which is 2.7 times higher than conventional ones and is close to sapphire. The sandwich structure provides appropriate internal loss.
The edge shape uses a tangential method with good linearity, and a low fo (250 Hz) is secured for smooth connection with the woofer.
We have also improved the equalizer to improve the connection with the tweeter and phase equalization.
For the voice coil, pure aluminum ribbon wire is reinforced with a oxygen-free copper coating for high input resistance.
A 3.6 cm hard dome type tweeter using an ATMC diaphragm is mounted in the high range as well as the middle range.
The edge uses a tangential edge formed integrally with the diaphragm to suppress unwanted resonance and obtain excellent transient characteristics. In addition, the directional characteristics are improved by reducing interference distortion with a high-precision equalizer.
The Network Division uses cut-and-try methods that focus on interviews to determine and adopt fixed numbers.
To achieve the transient characteristics of each unit, we use metallized film capacitors, laminated core coils made of carefully selected magnetic materials, and oxygen-free copper wire cords for internal wiring.
The enclosure has a thick walnut natural wood finish and is built with computer-controlled machining accuracy and strength.
In addition, the enclosure has a fully rigid structure with front, rear, left and right connecting reinforcing bars, and thorough standing wave measures have been taken to reduce the natural resonance of the enclosure.
Speaker cable of oxygen-free copper wire (0.18 mm φ x56 core) is included.
Model Rating
Method | 3-Way, 3-Speaker, Bass reflex system, Bookshelf Type |
Units Used | For low band : 31 cm cone type For Middle Area : 9 cm Dome Type For high-pass : 3.6 cm dome type |
Playback frequency band | 28 Hz to 33 kHz |
Impedance | 8 Ω |
Program source input | 150W |
Instantaneous maximum input | 300W |
Crossover frequency | 450 Hz, 6 kHz |
Output sound pressure level | 95dB/W/m |
External dimensions | Width 390x Height 710x Depth 380 mm |
Weight | 31kg |
Attachment | Speaker cable (3m) |