Technics SB-411
¥ 47,800 (1 unit, around 1974)
Commentary
This 3-way speaker system was developed using the SB-1000 technology.
A 25 cm cone type woofer is installed in the low range.
A TC cone is used for the diaphragm, and divided vibration is suppressed by a 3-layer structure in which a material with large internal loss is sandwiched by a material with high Young's modulus.
A laminated core magnetic circuit is adopted for the magnetic circuit. By adopting a laminated core made of special electromagnetic steel plates with large specific resistance and high saturation flux density, generation of eddy currents is suppressed and linearity is improved. In addition, a long travel voice coil with a winding width of 18.3 mm for the 8 mm plate thickness is adopted for the voice coil, improving linearity at Dainyu force and large amplitude.
50 micron aluminum foil is used for the voice coil bobbin to improve the input resistance.
The mid-range features a 3.5 cm dome mid-range.
The diaphragm uses the same TC structure as the woofer to suppress split vibration and abnormal resonance. The porous pole piece and back cavity eliminate distortion due to air pressure to improve the linearity of the vibration system and realize a wide band of fo700Hz.
A 1.9 cm dome type tweeter is installed in the high range.
Titanium foil is used for the diaphragm and edge. In addition, non-woven fabric with viscoelastic resin is pasted on the upper surface of the edge to suppress edge resonance which occurs in the low frequency range.
It has separate level controls for the mid and high ranges.
The enclosure uses a 25 mm thick particle board to minimize distortion and abnormal resonance.
Model Rating
Method | 3-Way, 3-Speaker, Airtight Type, Bookshelf Type |
Units Used | For low band : 25 cm cone type For Middle Area : 3.5 cm Dome Type For high-pass : 1.9 cm dome type |
Playback frequency band | 35 Hz to 20 kHz |
Impedance | 8 Ω |
Max Input | 46W |
Output sound pressure level | 90dB/W/m |
External dimensions | Width 330x Height 570x Depth 320 mm |
Weight | 19kg |