DIATONE DS-90C

Commentary

This high-end floor speaker system was developed by combining the latest technology and know-how accumulated through many years of speaker production.

A 40 cm cone type woofer using HC (honeycomb construction) cone is mounted in the low range.
The HC cone has a honeycomb-shaped honeycomb core made of thin aluminum foil sandwiched between thin glass fiber reinforced plastic (GFRP) films on both sides. As a result, the air layer occupies around 90% of the entire vibration plate, realizing a lightweight and highly rigid vibration plate. The HC cone has an extremely large weight-to-strength ratio and weight-to-rigidity ratio compared to other vibration plates, so the strain generated from the piston vibration region can be significantly reduced. In addition, by attaching a foam damping sheet on the back side of the vibration plate, an appropriate amount of internal loss is given and natural vibration is suppressed.
A low-distortion magnetic field circuit is used for the magnetic circuit. In this magnetic circuit, a special low-distortion ring (FN ring) made of iron-nickel alloy is installed in the magnetic pole gap to reduce non-linear distortion of the drive system generated from the magnetic circuit to less than 1/10 (-20dB) compared to conventional speakers.

A 16 cm cone type squaker is mounted in the middle area.
It uses low-distortion magnetic circuits that are also used in the Woofer, selected cone paper, Cross Edge with moderate viscoelasticity, voice coil with excellent input resistance, and die-cast frame. It has been developed through careful measurement and hearing tests.
In addition, since the directivity of the woofer begins to deteriorate at around 500 Hz, the crossover frequency is set to 350 Hz and used up to 3.5 kHz in order to compensate for this.

A 5 cm semi-dome type tweeter is installed in the high range.
The effective vibration radius of the cone is designed to be as small as possible. In addition to maintaining excellent directivity up to high frequencies, the piston vibration range is extended to reduce split vibration, and transient is improved by suppressing distortion. The allowable input is increased by designing the voice coil diameter to be large. In addition, the center dome has a special conical shape to increase rigidity and extend the piston vibration range to improve characteristics.

The squaker and tweeter are fixed in a sturdy diecast baffle 10 mm thick to prevent cavity resonance in the back of the squaker for a clear mid-to-high sound range without turbidity. The symmetrical arrangement of the units improves the directional characteristics of stereo playback.

A triangular duct is used for the bass reflex port to prevent resonance inside the duct and standing wave inside the cabinet.

The enclosure is a large enclosure with an internal volume of 206 liters. The internal structure is of a distributed resonance type. The vibration pattern of the enclosure is physically analyzed and reinforcing bars are distributed unevenly to suppress box rumbling.
The joints are firmly fixed using sophisticated woodworking techniques.

Model Rating

Method	3-Way, 3-Speaker, Bass Reflex System, Floor Type
Units Used	For low band : 40 cm cone type For Medium Range : 16 cm cone type For high-pass : 5 cm cone type
Rated impedance	8 Ω
Playback frequency band	20 Hz to 20 kHz
Output sound pressure level	95dB/W (New JIS)
Crossover frequency	350 Hz, 3.5 kHz
Max Input	100W
Level control	Mid-range : 5 positions (350 Hz to 3.5 kHz) High Frequency : 5 positions (3.5 kHz to 20 kHz)
External dimensions	Width 570x Height 1,075x Depth 480 mm
Weight	75kg