CORAL BETA-8
¥ 14,000 (1 unit, around the early 1970 s)
¥ 17,500 (1 unit, around 1980)
Commentary
BETA series 20 cm double cone type full-range speaker unit.
The diaphragm is made of pulp, the main raw material, mixed with chemical fibers to reduce the unevenness of thickness and density seen in conventional speakers. In addition, carefully selected diaphragm is used in white color to avoid coloring.
Strong and high-density pulp is specially treated for the subcone for the high-frequency band.
The voice coil uses copper-coated aluminum wire that combines the advantages of copper and aluminum wires.
It uses Coral's unique skybar edge and star-shaped diffuser that expands directivity.
Uses a prominent frame and allows flat mounting on the baffle surface.
Model Rating
| Type | 20 cm Double Cone Type Full Range Unit |
| Nominal impedance | 8 Ω |
| Program source input | 16W (around the early 1970 s) 35W (around 1980) |
| Lowest resonance frequency | 37Hz |
| Playback frequency band | Fo ~ 20 kHz |
| Output sound pressure level | 95dB/W/m |
| Magnetic flux density | 15,500gauss |
| Effective vibration radius (a) | 8.3cm |
| Equivalent mass of vibration system (mo) | 8.5g |
| Qo | 0.5 |
| Mechanical crossover | 6kHz |
| Maximum external dimensions | Diameter 233x Depth 113 mm |
| Baffle Hole Dimensions | 193mm 222 mm (when flat-mounted with prominent frame) |
| Mounting Hole Dimensions | 180mm 208 mm (when flat-mounted with prominent frame) |
| Weight | 3.3kg |
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