CORAL BL-25
¥ 49,800 (1 unit, around 1971)
¥ 31,300 (enclosure only, 1, circa 1971)
Commentary
A speaker system that combines a backload horn enclosure developed exclusively for BETA-10.
The unit is equipped with BETA-10 which is a 25 cm double cone type unit.
The enclosure uses a CW back-load horn, and no sound absorbing material is used inside.
In the CW system, the width from the throat to the opening of the horn is constant, and the flare of the horn is performed by changing the longitudinal dimension of the horn section. The horn is 17 inches (43 cm) wide, the opening is designed to be 10 inches (25 cm), 170 square inches, and the cutoff is approximately 90 Hz (fr = 1100/2L = 1100 / (2x6) = 92 Hz).
The entire surface is finished with teak material, and 22 mm thick plywood of Chinese material is used for the plate material.
Model Rating
Method | 1-way, 1-speaker, back-load horn system, floor type |
Units Used | For All Bands : 25 cm Double Cone Type (BETA-10) |
External dimensions | Width 475x Height 844x Depth 445 mm |
BETA-10 Specifications | |
Playback frequency band | 25 Hz to 20 kHz |
Lowest resonance frequency | 25 Hz to 40 Hz |
Crossover frequency | 6 kHz (Mechanical) |
Output sound pressure level | 103dB |
Program source input | 20W |
Impedance | 8 Ω |
Effective mass of vibration system | 16g |
Qo | 0.5(35Hz) |
Magnetic flux density | 15,500gauss |
Maximum external dimensions | 285mm |
Mounting Hole Dimensions | 240 φ (Prominent 272 φ) |
Baffle Hole Dimensions | 228 φ (Prominent 258 φ) |
Depth dimension | 133mm |
Weight | 4.6kg |