Technics SB-8

Commentary

This bookshelf speaker system is designed to be an acoustic transducer for the digital audio age, incorporating original technologies such as a honeycomb flat diaphragm.

Each speaker unit uses a honeycomb flat diaphragm that is light and highly rigid.
This diaphragm has a planar structure using an aluminum alloy-made honeycomb structure in order to obtain accurate piston motion while eliminating air resonance (front chamber effect) generated in the cavity in front of the cone of a cone-type speaker. Rigidity is 1,000 to 1500 times that of a paper cone. There is no distortion due to deformation caused by Dainyu force, or characteristic degradation due to aging or temperature change.
In addition, in order to solve the problem that a part that does not move at all (= node) at a specific frequency occurs when the center of the flat diaphragm is driven, we have adopted a node drive that drives by connecting a voice coil to the node. In addition, in order to cope with the problem that the appearance of nodes differs depending on the shape and frequency of the diaphragm, we have developed a unique axisymmetric honeycomb that increases the density of the honeycomb toward the center. By eliminating the difference in strength between the left and right sides, the node is made into a perfect circle, and node drive with one circular voice coil is possible.

A 32 cm honeycomb planar woofer is installed in the low range.
This unit uses a large diameter magnet with a diameter of 156 mm, and a polyimide voice coil bobbin and polyamide fusion coil, resulting in a high input resistance design that can withstand 250 ℃.
In addition, it is attached to the cabinet via a rubber ring to prevent transmission of vibration.

Equipped with 8 cm honeycomb planar skoker in the middle area.
The unique nodal drive allows the unit capable of piston motion up to 10 kHz to cross at 3.5 kHz, taking full advantage of the honeycomb plane and eliminating the inherent coloring.
Polyimide film is used for the voice coil bobbin to achieve high heat resistance and high input resistance.

A 2.8 cm honeycomb plane type tweeter is mounted in the high range.
The gap is filled with magnetic fluid, and the voice coil bobbin is impregnated with resin to achieve high input resistance. A special shape equalizer is mounted on the front of the unit.

For the network section, we have adopted a network in which boards are divided for low and high frequencies to minimize crosstalk between units by preventing interference with choke coils, etc. In addition, high-efficiency and low-strain self-fusion wires are used for choke coils in the woofer series, and metalized polyester film capacitors with excellent high frequency characteristics are used for the tweeter circuit.

The tweeter is equipped with a thermal relay protection circuit to prevent unit destruction caused by excessive input or excessive signal.

The enclosure is a 5-side finished real wood board enclosure.
It has a volume of 72L and is reinforced effectively by vibration analysis using the finite element method with the introduction of a computer to reduce unnecessary vibration. In addition, a three way Z-stop is adopted in the wooden framework to prevent distortion due to aging.
The VASREF port uses a specially shaped port that is integrally molded to prevent the leakage of standing waves in the enclosure, and has a smooth inner surface to reduce friction loss during air movement in the port.

Model Rating

Method	3-Way, 3-Speaker, Bass reflex system, Bookshelf Type
Unit	Low Band : 32 cm Flat Type For Middle Area : 8 cm Flat Type For High Frequency : 2.8 cm Flat Type
Frequency characteristic	36 Hz to 35 kHz -10dB
Output sound pressure level	94dB/W/m
Impedance	8 Ω
Allowable input	150W(Music) 100W(Din)
Crossover frequency	1.2 kHz, 3.5 kHz
External dimensions	Width 402x Height 711x Depth 372 mm
Weight	27.0kg