Audio Database

Picture of DS 503
Commentary

This speaker system was developed using the know-how obtained with the DS 505 as a digital reproduction standard system.

A 32 cm cone type woofer is installed in the low range.
The diaphragm uses a newly developed honeycomb cone that incorporates the know-how of the aramid honeycomb diaphragm mounted on the DS 505. This diaphragm uses high-tensile polyamide fiber as a skin material and greatly reduces strain caused by the diaphragm by suppressing axisymmetric split resonance.
In addition to the installation of a low-distortion magnetic circuit, an edgewise coil made of a flat oxygen-free copper wire and a voice coil bobbin made of glass-fiber polyimide film are employed to reduce the distortion of the drive system itself.

The mid-range features a 6.5 cm dome mid-range.
6.5 cmDUD Boron Dome is used for the diaphragm. Conventional metal diaphragm has high Q and sharp resonance, so measures such as attaching absorbers to the diaphragm itself have been taken. However, as a result, the residual sound, which is a component of the sound, is eliminated, which adversely affects the musical quality. To improve this, the Boron Dome used in the DS 503 has a non-treatment structure that does not apply any brakes to the diaphragm itself. Taking advantage of the features of DUD, the back pressure is controlled by inserting an equalizer in the upper part of the pole piece, and the diffuser in the front part is also eliminated.
In addition, in order to satisfy the two opposing conditions of good rise and no squeal, tangential edge is adopted by sandwiching aramid fiber with special butyl rubber. Aramid fiber has excellent damping characteristics and good response to quick rise sound. In addition, special butyl rubber is made by adjusting loss factor by slicing graphite and applying filler treatment to butyl rubber. Material with these two opposing properties is made into a sandwich structure, and by adjusting the film thickness, the response during attack is improved and squeal is suppressed.

A 2.3 cm dome-shaped tweeter is installed in the high range.
The diaphragm uses a DUD boron dome. In addition to the excellent characteristics of boron itself, the diaphragm and voice coil bobbin are integrated into a DUD structure to improve linearity and input resistance characteristics against input signals.

A low-distortion circuit is used for the network circuit. In particular, the mid-range network k circuit uses a newly developed electrolytic capacitor-based circuit instead of conventional film condensers to bring out the superior sound quality of the DUD-mid-range.
A oxygen-free copper Litz wire is used for connection between the tweeter and the network circuit to prevent lowering of the level at high frequencies due to skin effect and to improve response to instantaneous input.
Crimping sleeve wiring by oxygen-free copper is used for all connections.

The enclosure is of a distributed resonance type, and further rigidity is increased by joining the wrapping and fixing handle.
In addition, rigid straight aluminum pipes are used for the bass reflex duct.

Model Rating
Method 3-Way, 3-Speaker, Bass reflex system, Bookshelf Type
Units Used For low band : 32 cm cone type
For Middle Area : 6.5 cm Dome Type
For high-pass : 2.3 cm dome type
Rated impedance 6 Ω
Playback frequency band 30 Hz to 40 kHz
Output sound pressure level 90dB/W/m
Crossover frequency 500 Hz, 5 kHz
Level control Mid-range : 4 positions (500 Hz to 5 kHz)
High Frequency : 4 positions (5 kHz to 40 kHz)
Max Input 100W(EIAJ)
External dimensions Width 390x Height 720x Depth 377 mm
Weight 33kg