Technics SB-G90 Floorstanding Speaker

Description

Speaker System SB-G90

Unwanted vibration of the speaker units and enclosure has
been thoroughly eliminated. The floor-standing speaker achieves clarity in
sound imaging and fullness in spatial expression.

Point Sound Source Speaker System

One ideal in reproducing sound with full spatial expression
is to ensure that the wave-fronts emitted from the speaker units are aligned at
any listening position, i.e., providing a point sound source. While inheriting
the linear phase concept, the SB-G90 has newly developed two-way coaxial cone
units (including mid-range and tweeter) targeting high-speed reproduction with
enhanced high sensitivity.

Phase Precision Driver (Coaxial 2-way Speaker Unit)

A lightweight, high-rigidity anodized aluminium dome
diaphragm is used for the tweeter diaphragm. The driver reproduces a wide
frequency range up to 100 kHz by using a new dome shape optimized through
simulation, as well as achieving greater uniformity in phase characteristics by
using a phase plug. In addition, the SB-G90 uses high-linearity-drive underhung
voice coils, the magnetic gaps of which have had magnetic fluid injected to
suppress temperature rise, thereby ensuring superior power linearity. These
features provide reproduction of the high-frequency range with superb detail
and beauty.

As with the tweeter, the mid-range also uses an anodized, lightweight,
high-rigidity aluminium cone diaphragm. The magnetic circuit achieves low
distortion and enhanced drive power by using large magnets, copper caps, and
high-linearity-drive underhung voice coils. Also, the support structure
provided by the tough die-cast frame has resonance-dispersing arms, thereby
thoroughly eliminating even the slightest unnecessary resonant sound. These
features enable mid-range reproduction with excellent precision and response.

In addition, the mid-range diaphragm uses a cone shape in which its sound
generation centre in the axial direction is closer to the sound generation
centre of the tweeter, and the position of the axial direction of the dome
tweeter placed in the centre of the mid-range diaphragm is precisely adjusted,
thus achieving linear phase reproduction by integrating the sound in each range
without time lag. Also, the inside end of the mid-range diaphragm has a smooth
shape so there is no deterioration of tweeter sound characteristics, with the
diaphragm being constructed to deliver the sound emitted from the tweeter
directly to the listening space. This reproduces mid-range and highs with
superb precision and response, as well as excellent clarity in sound imaging.

BDMA (Balanced Driver Mounting Architecture)

With the conventional method of mounting a speaker unit to a
baffle, the centre of gravity of the speaker unit was located away from the
support points, and so the force acting on the voice coil when driving the speaker
produced vibration of the entire speaker unit. This produced distortion in the
sound waves generated from the diaphragm, resulting in deterioration of sound
quality. In addition, mounting the speaker unit to the baffle is a
configuration that easily transmits vibration of the speaker unit itself to the
baffle, and so unnecessary vibration sound was produced from the baffle, again
with deterioration of the sound quality.

With Balanced Driver Mounting Architecture, the speaker unit
is mounted to a sub-baffle installed inside the cabinet at the speaker unit’s
centre of gravity, suppressing vibration of the speaker unit. Also, because the
speaker unit is not mounted to the baffle on the front, transmission of
unwanted vibration from the speaker unit to the baffle is suppressed. This
makes it possible to reduce distortion in the sound waves generated from the
diaphragm and reduce unwanted vibration sound from the baffle, for reproduction
of a sound field with excellent sound imaging featuring impressive realism and
clarity, allowing visualization of the fine details of each and every sound.

16cm Low-distortion Long-stroke Woofer

The woofers have features such as double magnets producing
robust drive power, and magnetic circuits with high-linearity-drive overhung
voice coils, copper rings, and aluminium short rings. This newly developed
long-stroke unit achieves low-frequency reproduction with wide dynamic range as
well as excellent low distortion and response even for a large excursion. Also,
the support structure of the tough die-cast frame disperses resonance, thereby
thoroughly eliminating even the slightest unnecessary resonant sound. And, a
lightweight, high-rigidity anodized aluminium cone diaphragm is used to ensure
uniformity in tone with the mid-range and high frequencies.

These features reproduce robust, powerful bass.

High-quality Network Circuit

The high-precision network circuit was created through
repeated listening and redesign, in order to maximize the performance of each
speaker unit and achieve well-balanced sound. High-quality parts, such as a
polypropylene film capacitor, an air-core choke coil, and OFC wire used for
connection were carefully selected by examining their properties.

In order to prevent sound vibration emitted into the cabinet
by the speaker units from affecting the network, the network is installed in
its own compartment separated from the speaker units, thereby achieving
reproduction of sound providing an atmospheric feel.

High-rigidity Cabinet

Cabinet strength is ensured inside the cabinet by using a
cross construction with sub-baffles to which the speaker units are mounted and
horizontal reinforcing panels. A separate sub-baffle is used for each speaker
unit, which minimises sympathetic vibration between speaker units. In addition,
differentiated use of two kinds of absorbent acoustic materials with optimal
placement inside the cabinet suppresses internal standing waves and reduces
incidental sound due to reflection in the cabinet.

Also, multiple polyurethane (PU) coatings on the cabinet surface dampen cabinet
vibration, thereby thoroughly suppressing the production of unnecessary sound.
These features reproduce a vast sound field with excellent sound imaging.

Emotive Acoustic Technology
Point Sound Source Speaker System

Wide Range & Low Distortion Reproduction

Phase Precision Driver (Coaxial 2-way Speaker Unit)

16-cm Low Distortion Long Stroke Woofer

High-quality Network Circuit

Balanced Driver Mounting Architecture (BDMA)

High-rigidity Cabinet

Technics Definitive
Design
Black High Gloss Finish

Magnet Fixed Fabric Grille

Type
3-way 4-speaker Bass Reflex

(including 2-way coaxial cone units for mid-range and tweeter)

Speaker Units
Woofer: 16 cm (6½”) Cone type x 2

Midrange / Tweeter: Coaxial, 16 cm (6½”)

Cone type x 1 and 2.5 cm (1″) Dome type x 1

Crossover Frequencies
480 Hz, 3.2 kHz

Frequency Range
27 Hz – 100 kHz (-16 dB), 32 Hz – 85 kHz (-10 dB)

Sound Pressure Level
88 dB /2.83 V (m)

Impedance
4 Ω

Input Power (IEC)
100 W (Rated), 200 W (Max)

Recommended Amp Power
40 – 200 W

(Speaker tested by IEC60268-5 Short Term Max Test)

Dimensions (W x H x
D)
302 x 1114 x 375 mm

(11 7/8 x 43 27/32 x 14 3/4 in.)

(including fabric grille, terminals and spikes)

Weight (per unit)
Approx. 32 kg

(Approx. 71 lbs)

Accessories
Spike x 4, Spike shoe x 4, Spacer x 4, Base plate x 4, Base
plate screw x 12, Rubber foot x 4, Operating Instructions x 1, Speaker net x 1,
Cleaning cloth x 1