Technics SB-X3 Linear Phase Speaker System, 1978-79, made in Japan



Link: audio-heritage | hifiengine

39,500 (1 unit, around 1978)


A medium-sized speaker system of the SB-X series which realized the bookshelf type and linear phase design.

In order to realize Linear Phase theory in a bookshelf type, the SB - X series adopts a conical horn, and the midrange and the tweeter are withdrawn from the baffle surface.
In addition, the low range of each unit is smoothly enhanced by this conical horn, and low frequency distortion is also reduced by restraining this by a network, realizing low distortion of the system.

20 cm cone type Woofer is carried in low-pass.
This unit is a wide area unit with a high range extended to 5 kHz, and it has a high resistance tolerance design with heat resistance temperature of 200 ° C.

The 9 cm cone type mid range is carried in the mid range.
We are trying to reduce distortion by adopting a conical horn and also to improve the linearity at large amplitudes by paying attention to the shape and material of the edge and the material of the damper.



To the high region 2. The 5 cm dome type tweeter is carried.
The diaphragm adopts 15 micron ultra-thin titanium diaphragm, realizing high frequency characteristics and broadband. In addition, due to the ultrathinization, we added soft dome-like properties to the metal dome, and we are getting a good reverberation sound while suppressing peak occurrence.

In addition, the voice coil has heat resistance effect, adopting aluminum bobbin with good heat conduction, and realizing heat resistant temperature of 200 ℃ with heat resistant polyamide adhesive layer and polyester insulation layer.



Polyamide excellent in heat resistance is used for the voice coil adhesive layer of each unit, and polyester is used for the insulation layer. With this, we have obtained heat-resistant temperature of 180 ℃ ~ 200 ℃, achieving high resistance to input design.

Continuously variable attenuator is adopted as mid range and tweeter.
In addition, the tweeter is equipped with a thermal relay that protects the voice coil from excessive input.

Bass-reflex system is adopted for enclosure.
In addition, the front baffle has been decorated with silver metallic finish. I = 13> Bass reflex system is adopted for enclosure. In addition, the front baffle has been decorated with silver metallic finish. I = 13> Bass reflex system is adopted for enclosure. In addition, the front baffle has been decorated with silver metallic finish.

method 3 way · 3 speaker · bass reflex system · book shelf type
Used unit
  • For low-pass: 20 cm cone type For 
  • mid range: 9 cm cone type For 
  • high region: 2.5 cm dome shape
Frequency Response 42 Hz to 20 kHz - 10 dB
Impedance 6 Ω
Output sound pressure level 89 dB / W / m
Permissible input
  • 70 W (peak input) 
  • 40 W (DIN RMS)
Crossover frequency 1 kHz, 3.5 kHz
External dimensions Width 280 × height 537 × depth 256 mm (with net)
weight 11.5 kg (with net)