DIATONE DS-401

Commentary

A high-quality bookshelf speaker system that uses honeycomb cones.

A 30 cm cone type woofer using honeycomb cone is mounted in the low range.
The honeycomb cone consists of a honeycomb-shaped honeycomb core made of thin aluminum foil sandwiched between thin glass fiber reinforced plastics (GFRP) films on both sides. For this reason, the air layer occupies nearly 90% of the entire diaphragm, and it is light and highly rigid. In particular, the weight-to-strength ratio and weight-to-rigidity ratio are extremely large compared to other diaphragms, and the strain generated from the piston vibration region is greatly reduced. In addition, the honeycomb cone has an appropriate internal loss by sticking a foam damping sheet on the back side of the diaphragm, and the generation of natural vibration is suppressed. The lowest resonance frequency of the DS 401 is set at 37 Hz, which is combined with a low-distortion magnetic circuit to increase the reproduction capability of heavy bass.
The low distortion magnetic circuit adopted in the DS-35B is used for the magnetic circuit. In this magnetic circuit, a special magnetic alloy material with excellent linearity of magnetization characteristics developed by a metallurgical engineering approach is installed in the vicinity of the magnetic pole gap, and the non-linear distortion of the drive system generated from the magnetic circuit is reduced to less than 1/10 (-20dB) compared to the conventional one.

The mid-range is equipped with a 10 cm cone type squaker.
This unit is made as light as possible by adding fundamental consideration to the material of the cone paper. In addition, by applying moderate braking to the center cap, incidental noise which was thought to be difficult to control is eliminated. In addition, it is molded to be strong to match the air suspension system well.
A low-distortion magnetic circuit is used for the magnetic circuit like the woofer, and a die-cast frame is used for the frame to further reduce distortion.

A newly designed 4 cm semi-dome type tweeter is installed in the high range.
The diaphragm is made of Konica Le Dome GFRP, and the piston vibration range is extended to achieve smooth frequency characteristics up to the high end.

By adopting new technology in the network section, distortion is reduced.
In addition to pursuing physical characteristics by strictly checking the materials of coils, capacitors, and resistors, as well as the winding and circuit configuration, hearing tests have been conducted to an extent that is audibly satisfactory. As a result, we have adopted a core coil for the coil to improve damping, a metallized polyester film capacitor for the capacitor, and a well-examined cement resistor for the level adjustment resistor.
This low-distortion network circuit realizes clear playback sound in the entire playback band from the heavy low range to the super high range.

It is equipped with 4-position switching type level control for the middle and high frequency ranges respectively.

The front baffle has a symmetrical vertical single row unit configuration with a squaker and a tweeter positioned slightly inward from the center line to improve sound image localization.

The enclosure employs an air suspension system, which brakes the cone paper by suppressing the air in the enclosed enclosure.
In addition, by adopting a dispersion resonance type enclosure with a strong joint structure and special dispersion type reinforcing beam, the resonance mode is dispersed and the box ringing phenomenon is suppressed.

The exterior features a natural walnut veneer finish.

Model Rating

Method	3-way, 3-speaker acoustic air suspension system ・ Bookshelf type
Units Used	For low band : 30 cm cone type For Medium Range : 10 cm Cone Type For High Range : 4 cm Semi-dome Type
Nominal impedance	6 Ω
Playback frequency band	30 Hz to 20 kHz
Crossover frequency	500 Hz, 5 kHz
Output sound pressure level	89dB/W/m
Max Input	80W
Level control	Mid-range : 4 positions (500 Hz to 5 kHz) High Frequency : 4 positions (5 kHz to 20 kHz)
External dimensions	Width 370x Height 675x Depth 326 mm
Weight	25kg