ALTEC LANSING 420A
* Released in 1968
¥ 54,300 (1 unit, around 1970)
¥ 57,800 (1 unit, after 1970 price revision)
¥ 54,700 (1 unit, around 1976)
Commentary
This 38 cm special cone type full-range speaker unit was also used in the 879A Santa Ana.
The 420A is called a bi-flex speaker. It consists of a large cone and a 16 cm diameter cone with different stiffness integrated into a multi-dumped corrugation. This enables playback with less distortion from the ultra-low, mid-low and mid-range included in the program source.
Also, in the center of the cone, the dome radiator made of light alloy is in charge up to the upper limit of the high range.
The voice coil uses a 75 mm diameter voice coil with aluminum ribbon wire edgewise winding, and the magnetic circuit uses a 11,400 gauss, 4.9 kg internal magnetic type Alnico V.
The magnetic circuit of Altec products is excited only up to the specified magnetic flux density, and the sharp decrease in holding force and uneven quality caused by the magnet excited to the limit are suppressed.
A strong aluminum die-cast frame is used for the frame part to suppress distortion due to aging and resonance due to cone vibration.
Model Rating
| Type | 38 cm special cone type full-range speaker |
| Frequency characteristic | 25 Hz to 14 kHz |
| Lowest resonance frequency | 27Hz |
| Impedance | 8 Ω |
| Rated input | 25W |
| Allowable input | 50W |
| Magnet used | 4.9 kg Alnico V |
| Magnetic flux density | 11,400gauss |
| Crossover frequency | 1 kHz (Mechanical) |
| External dimensions | Diameter 386x Depth 178 mm |
| Weight | 7.9kg |