Technics SB-1000

Commentary

This system was developed with the theme of reducing distortion among various characteristics of speakers.
All units in use have been newly designed, making full use of new methods and materials for the magnetic circuit, vibration system, and suspension, and also for the system, including the network and cabinet, pursuing a thoroughly low strain rate structure.

A 30 cm cone type unit is used for the low range.
The diaphragm uses a TC cone made by multi-stage diaphragm making technology. A three layered one sheet diaphragm is made by sandwiching a material with high Young's modulus and high internal loss.
As a result, split vibration is suppressed and sound pressure characteristics in the mid - and high-frequency range are kept flat.
We also noticed that there is a balance relationship between the voice coil diameter and the diaphragm diameter to reduce split vibration. As a result of our research, we chose a voice coil of 100 φ as the best diameter.
The suspension uses a symmetric double structure damper to eliminate secondary strain. Moreover, the effect of the damper is large even against lateral vibration. It is combined with the soft urethane foam convex roll high-compliance edge, which is well known for its good linearity, and the linearity of the vibration system is improved.
In addition, there is a hole in the center of the pole piece to minimize distortion caused by air pressure fluctuation in the empty space at the rear of the dust cap.
In order to suppress the generation of over-current inside the magnetic body, which is the cause of distortion by the magnetic circuit, we have adopted a laminated core of special electromagnetic steel plates with high specific resistance and high saturation magnetic flux density near the voice coil of the pole piece plate to improve the linearity of the AC magnetic circuit.
In addition, in order to improve the linearity of driving force during large vibration, we have adopted a drive system using a long plate short voice coil with a large magnetic pole width and a small voice coil width. The voice coil is driven within a constant magnetic flux even at a large amplitude of ± 7 mm, and there is no linearity loss due to magnetic leakage.

A 4.5 cm dome type unit of 3-layer TC diaphragm by multi-stage diaphragm manufacturing is adopted for the middle area.
The magnetic circuit uses a laminated core made of special electromagnetic steel plates to minimize distortion in the magnetic circuit.
In addition, the voice coil bobbin is supported by a double damper, and a perforated pole piece dumped with sound absorbing material and a back cavity are provided to improve the linearity of the vibration system.

A 1.9 cm dome type unit with a diaphragm made of ultra-thin titanium 20 μ m thick is used for the high-frequency range.
Titanium is also used for the edge, and low strain rate is realized by the damping material and edge hole.
In addition, it is 30% lighter than aluminum and has excellent transient characteristics.
The magnetic circuit uses Permendur (Fe-Co alloy) with extremely high saturation magnetic flux density and high specific resistance, and achieves a magnetic flux density of 19,000 Gauss.

The network is also conscious of low distortion factor, and silicon steel plate E-core winding is adopted for the choke coil, and ultra-low distortion factor of over 0.1% is realized even at large output of 100W.
We have also adopted MP capacitors for some of our capacitors.

The enclosure consists of 3 layers of 9 mm plywood + 18 mm rigid particle board + 9 mm plywood for a total thickness of 36 mm.
This reduces resonance, which causes distortion, transient characteristics and frequency characteristics deterioration, and eliminates unnecessary radiation from the enclosure surface due to increased internal pressure.
In addition, the die-cast frame of the unit has been extended into a square shape, and it is designed to fit into the cabinet and baffle.

Equipped with direct-connected multi - and full-range input terminals to eliminate the increase in contact resistance caused by the switch and prevent damping degradation.

Model Rating

Method	3-way, 3-speaker, acoustic suspension system, bookshelf type
Units Used	For Low Range : 30 cm Cone Type (EAS-30PL100S) For Middle Area : 4.5 cm Dome Type (EAS-18KM100S) For High Range : 1.9 cm Dome Type (EAS-12KH100S)
Playback frequency band	20 Hz to 30000 Hz
Impedance	8 Ω
Output sound pressure level	90dB/W/m
Max Input	100W
Crossover frequency	500 Hz, 5000 Hz Multi-amplifier mode Low to mid range : 400 Hz to 1 kHz Medium to High : 2.5 kHz to 7 kHz
Level control	For Middle Range : + 2 ~ 0 ~ -6dB For High Range : + 2 ~ 0 ~ -6dB
External dimensions	Width 392x Height 582x Depth 397 mm
Weight	52kg