Technics SB-3
¥ 32,000 (1 unit sold in November 1979)
Commentary
A 2-way speaker system using a honeycomb planar vibrating plate.
A flat woofer with a 22 cm honeycomb disk diaphragm is mounted in the low range.
A powerful 100 mm diameter magnet is used and a 32 mm diameter voice coil is used to drive a honeycomb planar vibration plate through a hard aluminum drive cone. This, combined with the characteristics of an axisymmetric honeycomb disk, expands the piston motion range to the high frequency of 2.5 khz, reduces the distortion of the vibration system, and realizes smooth frequency characteristics.
The voice coil uses CCAW, which is excellent in heat dissipation, and the bobbin uses heat-resistant polyimide laminated film to improve input resistance.
In addition, the edge has a down roll shape to prevent diffraction, and an aluminum die-cast frame is used to prevent unwanted resonance of the unit.
A flat type tweeter using a 2.8 cm honeycomb disk diaphragm is mounted in the high frequency range.
This unit directly drives the nodes of a lightweight and highly rigid diaphragm with a 19 mm diameter voice coil. As a result, the first resonance mode is canceled and the piston motion range of the disk tweeter is extended from 1 kHz to 32 kHz. In addition, by using a flat diaphragm, there is no cavity effect (front chamber effect) and smooth and flat frequency characteristics are obtained.
The voice coil uses CCAW for good heat dissipation, aluminum foil bobbin for high input resistance design, and an equalizer on the front to improve the high-frequency characteristics of the tweeter.
The tweeter is equipped with a thermal relay protection circuit to prevent unit breakage due to abnormal signals or excessive input.
It is also equipped with an attenuator for adjusting the tweeter level.
Model Rating
| Method | 2-Way, 2-Speaker, Airtight Type, Bookshelf Type |
| Units Used | For Low Band : 22 cm Flat Type For High Frequency : 2.8 cm Flat Type |
| Frequency characteristic | 45 hz to 35 khz -10dB |
| Impedance | 8 Ω |
| Output sound pressure level | 90dB/W/m |
| Allowable input | 50W(DIN) 75W(MUSIC) |
| Crossover frequency | 1500Hz |
| External dimensions | Width 270x Height 440x Depth 237 mm |
| Weight | 8.6 kg (With Net) |
| Sold Separately | Speaker Stand SH-S30 (1 set of 2, ¥ 17,000) |