¥ 1,000,000 (1 unit, sold in November 1988)
¥ 933,000 (1 unit, around 1989)
This floor-type speaker system was developed by bringing together the best of Diatone acoustic technology.
It has a 40 cm cone woofer in the low range and a 25 cm cone midbus unit in the middle and low range.
The Woofer and Midbus use Advanced Intraply Hybrid Honeycomb Diaphragm.
This diaphragm is based on the Intra-Ply hybrid honeycomb diaphragm which pursues high-speed reproduction capability by high rigidity of the front skin, moderate loss, and attenuation beauty after the signal disappears by the uraskin.
In the advanced intra-ply hybrid honeycomb diaphragm, the front skin is overlaid with an aromatic polyamide aramid and PAN-based high-strength carbon fiber intra-ply and a new aromatic polyamide aramid. In addition, the back skin is also overlaid with an aromatic polyamide aramid, and an aluminum honeycomb core is sandwiched in a double hybrid structure. This realizes a diaphragm that takes advantage of the characteristics of aromatic polyamide aramid with high strength rigidity, light weight and moderate internal loss, and the advantages of PAN-based high-strength carbon fiber with extremely high specific elastic modulus.
The A.D. M.C. (Advanced Magnetic Circuit) is used for the magnetic circuit of Woofer and Midbus.
This magnetic circuit was realized by analyzing and pursuing various magnetic circuits such as ferrite, alnico, and anti-magnetic type from various viewpoints such as complex method and finite element method. It is intended to reduce magnetic distortion caused by distribution shape of DC magnetic flux, current distortion due to AC magnetic flux of voice coil current, AC component in magnetic flux, etc.
In the A. D. M. C., the center pole shape has been revised in order to enhance the symmetry of the DC magnetic flux distribution shape crossing the voice coil. The AC magnetic flux is offset by arranging conductive short rings above and below the center pole. This suppresses the magnetic fluctuation caused by the superposition of DC and AC, stabilizes the magnetic circuit, and reduces harmonic distortion. In addition, the adverse effect of AC magnetic flux in the magnet on the DC magnetic field is also suppressed.
Additionally, the Woofer and Midbus use Advanced D. M. M. (Direct Magnet Circuit Mount).
In the D. M. M., the whole magnetic circuit is firmly fixed by the frame in order to aim at high rigidity of the unit, and excellent start-up characteristics are realized. The Advanced D. M. M. is a further development of this. The rigidity of the magnetic circuit is high for the fundamental wave, and the osae komi of the magnetic circuit is stable, and for the higher mode, the damping is fast and natural. This suppresses the natural sound of the center pole and the natural sound of the frame that stains the middle and high range, and realizes high-resolution reproduction with good S/N.
A 6.5 cm dome mid-high unit is installed in the middle and high range, and a 2.3 cm dome type tweeter is installed in the high range.
B for mid-high and tweeter4C (pure boron) diaphragm is adopted.
Pure Boron has a specific elastic modulus 5 times that of titanium and 2.2 times that of Boronized titanium. It also has an appropriate internal loss due to its nonmetal nature. However, because of its extremely high melting point of 2,450 ℃, it was impossible to mold it into a dome shape using conventional technology.
Diatone solves this problem by plasma spraying at a high temperature of 15,000 ℃ using a unique plasma spraying method, followed by high-temperature firing in an inert gas atmosphere.4A pure boron diaphragm with strong bonding between C particles and few voids has been realized.
B4In order to make the best use of the C-diaphragm characteristics, the Mid-high and Tweeter units have D. U. D. and D. M. structures.
The D. U. D structure can transmit the driving force generated in the voice coil to the diaphragm without loss, resulting in less attenuation in the high-frequency range and improved response to input signals. In addition, it can set the high-frequency resonance frequency to be high, and the linearity and input resistance to input signals can be improved by high heat radiation effect.
In addition, the D. M. (direct mount) structure is a high-rigidity unit structure unique to Diatone. The monocoque structure, in which the plate part of the magnetic circuit is made into a mount plate, allows the magnetic circuit to be mounted directly in the enclosure, making the rigidity of the whole unit high.
The magnetic shielding covers of all units are made of spheroidal graphite cast iron, which has excellent magnetic properties, a high balance of high rigidity and damping properties, and is also used for piano frames, etc., to prevent magnetic interference from the outside.
In order to minimize the effects of magnetic interference and vibration on the network, the network section is divided into two sections. After that, we thoroughly review the body materials and determine the layout.
All network circuits are made of the highest-purity oxygen-free copper wire, and the same oxygen-free copper wire is used for wiring. In addition, the connection by sleeve crimping method and direct balance power supply method are adopted to suppress the deterioration of sound quality in the network section.
Two separate sets of input terminals for low frequency and high / high frequency band are mounted for bi-amplifier connection.
All terminals are gold-plated.
In order to prevent mutual interference between units inside the enclosure, a round-shaped back chamber is installed around the midbus, and the rear of the midbus unit is made into an independent space. It is made of a material that is highly rigid yet has a beautiful sound. Moreover, the perfect R-shape realizes a highly rigid structure that resists back pressure.
In addition, by controlling the radiation impedance at the back of the unit, it contributes to suppressing standing waves in the vertical direction in the cabinet.
Sound radiation analysis is used to determine the optimal placement of each unit in the enclosure. The structure of the entire enclosure is also thoroughly examined, and the high-rigidity method is advanced in every corner while the damping characteristics are further pursued.
The front baffle is made of 38 mm thick Siberian Karamatsu Plywood with excellent damping characteristics and beautiful sound. In addition, computer analysis is used to enhance the rigidity of the front baffle. At the same time, the four corners of the enclosure are reinforced with highly rigid Tamo Sawn Board.
A dedicated acoustic base is included.
|Method||4-Way, 4-Speaker, Basref System, Floor Type, Anti-Magnetic Field (EIAJ) Type|
|Units Used||For low band : 40 cm cone type
For middle and low band : 25 cm cone type
For Middle and High Areas : 6.5 cm Dome Type
For high-pass : 2.3 cm dome type
|Nominal impedance||6 Ω|
|Playback frequency band||18 Hz to 80 kHz|
|Output sound pressure level||92dB/W/m|
|Crossover frequency||300 Hz, 1.25 kHz, 4 kHz|
|External dimensions||Width 652x Height 1,080x Depth 497 mm|