Audio Database

Picture of DS-77HR
Commentary

This speaker system pursues not only high rigidity but also the hybridate concept that combines high specific elastic modulus and optimum loss factor in a high dimension.

Woofer
A 31 cm cone type woofer is installed in the low range.

The diaphragm uses an aramid hybrid honeycomb diaphragm with an aramid hybrid FRP for the front skin and a cellulose fiber skin for the back skin.
The aramid hybrid FRP used for the front skin has an intra-ply structure of aramid organic fiber and amorphous silica inorganic fiber. Aramid fiber is an aromatic polyamide fiber material with low density and moderate internal loss in addition to high strength and high specific elasticity. Amorphous silica is a fiber with high rigidity itself. By weaving these two fiber intra-ply structures and hybrid weaving, the skin material with high specific elastic modulus and optimum loss factor is obtained. The cellulose fiber skin used for the back skin is a skin material made from cellulose fiber with excellent internal loss. The hybrid structure of these two a hybrid structure, the optimum physical properties as a low-frequency diaphragm are realized while drawing out the advantages of each.

The frame structure uses a highly rigid R. S. frame with an 8-point lock for secure mounting in the enclosure.

midrange
The mid-range is equipped with a 10 cm cone type squaker.

The cone part of the diaphragm employs an intra-ply hybrid diaphragm with an intra-ply structure made of organic fiber aramid and inorganic fiber PAN-based high-strength carbon fiber.
The PAN-based high-strength carbon fiber uses polyacrylonitrile as a raw material and has an extremely high specific elastic modulus. By hybrid weaving this and the organic fiber aramid as an intra-ply structure, a high-dimensional balance between high specific elastic modulus and loss factor is achieved while keeping each characteristic high dimension.

The center diaphragm of the diaphragm uses S. R. Titanium Dome which balances high specific elastic modulus and loss factor by surface hardening of titanium.
By making the entire diaphragm a hybrid structure of a metal diaphragm and an FRP cone diaphragm, the connection of reproduced sound is improved.

Tangential edge is used for the edge part.
This edge is a laminated structure for resonance control with two tangential cloths coated with a special damping material to improve response, and realizes flattening of characteristics and reduction of strain.

In order to increase the rigidity of the unit, the R. S. frame is used as well as the woofer.

Tweeter
A 2.5 cm dome type tweeter is installed in the high range.

The diaphragm uses S. R. Titanium Dome which achieves both high hardness and moderate internal loss by surface hardening treatment of titanium.
In addition, by adopting Diatone's unique D. U. D structure in which the driving voice coil is directly wound around the diaphragm, we have achieved a wide response band and high-speed response to pulsed input at a high dimension.

The unit structure adopts Diatone's unique D. M. (direct mount) structure.
In the D. M. structure, part of the magnetic circuit is framed and mounted directly on the baffle plate. Low-carbon soft hard material with excellent magnetic properties serves as the conventional frame. In the DS-77HR, the entire plate is wrapped with aluminum alloy casting material and mounted in the enclosure in order to convert the resonance of this material into frictional heat generated at the interface between dissimilar metals and attenuate it. Thus, in addition to high rigidity, resonance is suppressed low with high damping effect, and a unit structure that radiates the sound of the diaphragm is realized.

Network
A crimping wiring method has been adopted for connection of the network. By passing the wires through the sleeve and crimping and crimping them together, the strain at the boundary between dissimilar metals caused by soldering is eliminated and acoustic characteristics are improved.
In addition, in order to reduce power supply loss due to the wiring system, the wiring after the input terminal is made independent for each unit. In particular, the wiring connection from the input terminal to each unit uses a one point concentrated clinching method to provide a well-balanced current supply.

It uses a two part structure with separate woofer elements that generate large magnetic flux, eliminating intermodulation that can cause muddy sound quality. It also uses laminated orient cores for coils and oxygen-free copper wires for electrical wires.
Capacitors and resistors are also carefully selected after repeated measurement and viewing.

Enclosure
A large oval 4-side round baffle with four rounded sides around the front baffle has been adopted to suppress the diffraction phenomenon of sound waves and improve sound image localization and sound spread.

It employs an enclosure structure that makes full use of Diatone's unique analysis technology, including modal analysis.
For the DS-77HR, we use carefully selected plate materials that are highly rigid but have less natural sound. For the primary vibration mode, we increase the rigidity of the enclosure itself, and for the higher-order mode, we use Diatone's unique dispersion resonance type to reduce resonance.

Other
There was a special speaker stand, DK-77 which was developed for DS-77HR and sold separately.
The DK-77 uses the same high-density particleboards as the DS-77HR enclosure, and controls standing waves by reducing parallel planes from the form as much as possible.
In addition, a unique adjuster is used to stabilize the bottom of the legs.

The DS-77HR comes in two color variations, a walnut finish and a black wood finish.
Also, DK-77 has 2 color variations like DS-77HR.

Model Rating
Method 3-Way, 3-Speaker, Airtight Type, Bookshelf Type
Units Used For low band : 31 cm cone type
For Medium Range : 10 cm Cone Type
For high-pass : 2.5 cm dome type
Nominal impedance 6 Ω
Playback frequency band 35 Hz to 30 kHz
Output sound pressure level 91dB/W/m
Crossover frequency 500 Hz, 4 kHz
Max Input 230W(EIAJ)
External dimensions Width 380x Height 680x Depth 325 mm
Weight 27kg
Sold separately : Speaker Stand DK-77 (WN/BK, 2 pcs 1 set, ¥ 35,000)
External dimensions Width 380x Height 304x Depth 310 mm
Weight 10kg