CORAL 8A-70

Commentary

A70 series 20 cm cone type full-range speaker unit developed as a scale-up model of 4A-70.

The corn paper uses carefully selected pulp materials. In order to make the best use of these materials, it is swaged after special heat treatment. In addition, the Coral's unique hardness treatment is applied. Both mass and elastic modulus satisfy the ideal for corn paper.

A corrugation edge is used for the edge, and by applying a careful coating with a damping agent, non-linear strain is suppressed and linear tracking performance is exhibited.

A new lead method has been adopted for wiring from the voice coil, eliminating the need for an eyelet of cone paper. This allows even a pulsed input signal to be transmitted smoothly to the cone paper, improving power and resolution.

The voice coil has heat radiation effect and heat resistance at high power, and the center pole is plated with copper to reduce strain and improve transient response characteristics.
In addition, ferrite magnet with large holding force is adopted.

Model Rating

Type	20 cm cone type full range unit
Nominal impedance	8 Ω
Program source input	50W
Lowest resonance frequency	45Hz
Playback frequency band	Fo ~ 16 kHz
Output sound pressure level	93dB/W/m
Magnetic flux density	10,500gauss
Effective vibration radius (a)	8.25cm
Equivalent mass of vibration system (mo)	14.5g
Qo	0.45
Baffle opening diameter	200 mm φ (Front Mounting)
Weight	3.5kg