DIATONE DS-303

Commentary

This speaker system was developed as a high-end model following the DS 301.

In order to realize an excellent speaker, it is designed not only by measuring in an anechoic room, but also by measuring under various conditions such as characteristics when placed directly on a floor plate and characteristics when embedded in the ground assuming an infinite baffle.

A 30 cm cone type woofer, PW-30BM is mounted in the low range. 3040 bm.

It is equipped with DM-6010CM which is a 6 cm dome type squaker in the middle range, DH-2310CM which is a 2.3 cm dome type tweeter in the high range, and DH-1670BM which is a 1.6 cm dome type super tweeter in the ultra high range.
The diaphragms of these units are made of phenol resin, paper, and soft aluminum from the viewpoint of performance and sound quality, respectively, and we have succeeded in obtaining natural sound connections.

The mid-range, high-range and ultra-high-range are equipped with independent coil tap step-type attenuators.
You can control four levels each for the middle and high ranges, and three levels for the ultra high range.

In the DS 303, the Woofer unit is damped at 600 Hz, which is one octave lower than the piston vibration limit, and connected to the Skoker unit. In addition, the Woofer unit is connected to the Tweeter unit at 5 kHz, which is one octave lower than the limit frequency of the Skoker. In addition, the Tweeter is connected to the Super Tweeter at 10 kHz, which is one octave lower than the frequency at which the characteristics begin to be disturbed as it enters the divided resonance range.
As a result, the crossover frequency is naturally connected and the power response is smooth. The good range of piston vibration stabilizes the characteristics of the speaker unit and stabilizes the physical characteristics and sound quality of the system.

The enclosure uses a symmetrical design for the first time as a diatone. By improving directional characteristics, the difference in sound quality between the left and right sides of the system is eliminated.
In addition, an edgeless cabinet with a flat outer periphery of the front baffle has been adopted to improve the directional disturbance that occurs when the outer periphery of the front baffle protrudes from the design of old speaker systems. In addition, to eliminate the influence of the front net, a slit is installed on both sides of the front and left sides.

The selection of cabinet materials is based on physical data and audibility tests. Multi-layer particleboards are used for the five sides except for the back, and Canadian douglas fur with excellent damping characteristics is used for the back plate.
In addition, the use of a dispersion type reinforcing bar prevents resonance from concentrating and provides natural attenuation characteristics.

The DS 303 is designed to determine how much power should be used to drive an amplifier when listening to music.
In order to ensure a sound level of 100 dB (instantaneous value) in stereo reproduction in a large listening room of 12 to 16 tatami mats, an input resistance of 100W is required for efficiency, and an output power of at least 40W is required in order to satisfy the conditions in a small room of 4.5 or 6 tatami mats.
For this reason, it was recommended that the DS 303 be driven by an amplifier with an output of approximately 40W to 100W.
(See graph below on listening level and distance from speaker system)

Model Rating

Method	4-way, 4-speaker, acoustic air suspension system ・ Bookshelf type
Units used, etc.	For Low Band : 30 cm Cone Type (PW-3040BM) For Middle Area : 6 cm Dome Type (DM-6010CM) For High Range : 2.3 cm Dome Type (DH-2310CM) For Super High Band : 1.6 cm Dome Type (DH-1670BM)
Rated impedance	6 Ω
Playback frequency band	30 Hz to 35 kHz
Output sound pressure level	90dB/W (New JIS)
Crossover frequency	600 Hz, 5 kHz, 10 kHz
Max Input	100W
Level control	For Middle Range : 4 Positions High frequency : 4 positions For Super High Band : 3 positions
External dimensions	Width 360x Height 620x Depth 328 mm
Weight	34kg