DIATONE DS-70C

Commentary

A floor-type speaker system incorporating a 33 cm honeycomb cone type woofer into a large bass reflex enclosure.

A 33 cm cone type woofer using a honeycomb cone diaphragm is mounted in the low range.
The honeycomb cone is a honeycomb core made of thin aluminum foil and sandwiched between thin glass fiber reinforced plastics (GFRP) films on both sides. As a result, the air layer occupies around 90% of the entire diaphragm, achieving both high rigidity and lightweight.
The low distortion magnetic circuit adopted in the DS-35B is used for the magnetic circuit. This magnetic circuit has a structure in which a special magnetic alloy material with excellent linearity of magnetization characteristics developed by a metallurgical engineering approach is mounted near the magnetic pole gap. This reduces the nonlinear distortion of the drive system generated from the magnetic circuit to less than 1/10 (-20dB) compared to conventional speakers.

Newly designed 12 cm cone type skoker is mounted in the middle area.
In this unit, the weight is reduced by fundamental consideration of the material of the cone paper, and by applying moderate braking to the center cap, incidental noise, which was difficult to suppress in the past, is eliminated.
In addition, the upper part is molded to match the bass reflex method, and distortion is reduced by adopting a low-distortion magnetic circuit and die-cast frame.

A 4 cm semi-dome type tweeter is installed in the high range.
The diaphragm is made of GFRP, which is light and highly rigid, in the shape of Konica Le Dome. By extending the piston vibration range, smooth frequency characteristics are achieved up to the high end.

In order to reduce the distortion of the network section, physical tests and hearing tests are repeatedly carried out. In addition, the materials of coils and capacitors, windings, and circuit configuration are examined.
The DS-70C uses an L-element with sufficient consideration for DC resistance through the use of a laminated core, and metalized polyester film and condenser that have been carefully examined in terms of sound quality. This reduces distortion in all bands.

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

The front baffle has been adopted for the front baffle, and the sound image localization has been improved by placing the squaker and the tweeter inside the center line of the baffle plate.
The enclosure uses a newly designed bass reflex system. The port of the bass reflex duct is located at the same height as the skoker, so that it is less affected by the floor surface. In addition, a twin triangle duct with rectangular ports divided diagonally is used to prevent port noise by preventing the occurrence of standing waves.

Model Rating

Method	3-Way, 3-Speaker, Bass Reflex System, Floor Type
Units Used	For low band : 33 cm cone type For Medium Range : 12 cm cone type For High Range : 4 cm Semi-dome Type
Rated impedance	8 Ω
Playback frequency band	25 Hz to 20 kHz
Output sound pressure level	92dB/W
Crossover frequency	500 Hz, 5 kHz
Max Input	80W(EIAJ)
Level control	Mid-range : 4 positions (500 Hz to 5 kHz) High Frequency : 4 positions (5 kHz to 20 kHz)
External dimensions	Width 470x Height 930x Depth 397 mm
Weight	49kg