Pioneer AS-31
¥ 20,000 (released in 1973)
Commentary
2-way speaker system kit.
A 30 cm cone type woofer is used for the low range.
The voice coil uses high-density edgewise winding. Compared with the conventional type, the air gap utilization rate is better, and efficiency and input resistance characteristics are greatly improved.
The center pole of the magnetic circuit is equipped with a pure copper cap to reduce magnetic distortion.
FB cone is used for the cone paper, and special urethane foam material is used for the edge.
A commercially available horn-type speaker unit PM-40 is used for mid-range and high-range applications.
The driver unit is equipped with a sound channel in the diaphragm packing to eliminate distortion and disturbance of characteristics. In addition, a sound absorbing material is inserted into the yoke to absorb unnecessary sound pressure. Thus, the sound quality is improved.
A commercially available AT-8B is used for the level control and can be varied from 0 dB to ∞ dB.
The network is designed to be -12dB/oct with built-in impedance correction circuitry to improve transient characteristics.
There was a special enclosure LE-B31 sold separately.
.JPG)
Model Rating
| Type | 2-way speaker system kit |
| Kit part | 30 cm Cone Woofer Horn Type Mid High Range (PM-40) Network Level Control (AT-8B) Speaker mounting packing Level control mounting packing Self-made enclosure pattern paper 18 cross recessed round head screws (3.5x25mm for speaker) Flat Washer (for Speaker) x18 Spring washer (for speaker) x18 Cross Recessed Round Head Screw (Network 2.7x13mm) x6 Three cross recessed round head screws (3.1x20mm for level control) |
| Characteristics of AS-31 + LE-B31 | |
| Cabinet type | Closed type |
| Impedance | 8 Ω |
| Frequency characteristic | 40 Hz to 16 kHz |
| Output sound pressure level | 91dB/W |
| Max Input | 75W |