MISSION 770Freedom
¥ 156,000 (a set of two cars, around 1987)
Commentary
A speaker system developed as an improved version of the 770.
In addition to expanding the frequency band and achieving clear and sharp bus response, 770 Freedom is designed to solve problems such as nonlinear compression and saturation by expanding the allowable limit of the dynamic range.
A 21.5 cm cone type woofer is installed in the low range.
The diaphragm is made of a homopolymer mineral-fired plastic cone to meet conflicting requirements for impulse response, sensitivity, damping and internal loss.
The brass plated center pole has a special shape, and the heat-resistant voice coil material and efficient heat dissipation design increase power handling.
A die-cast frame has been adopted for the frame to suppress unnecessary vibration.
A 2.5 cm dome-shaped tweeter is installed in the high range.
The unit has a short elliptical horn at the front, impedance transforms to eliminate the habit of the dome tweeter, and is cooled by magnetic fluid to avoid thermal damage, while increasing the saturation limit.
The enclosure structure is based on a folded-back shape to ensure rigidity against transient response in the low-frequency band and eliminate adverse effects in the mid-frequency band.
In order to ensure phase coherence, the walls of the cabinet are damped using viscoelastic material to control and attenuate resonance and to minimize excess sound output.
There was a speaker stand sold separately.
Model Rating
| Method | 2-Way, 2-Speaker, Bass Reflex System, Bookshelf Type |
| Units Used | For low band : 21.5 cm cone type For high-pass : 2.5 cm dome type |
| Frequency characteristic | 35 Hz to 20 kHz ± 3 dB |
| Impedance | 8 Ω |
| Recommended amplifier output | 30W ~ 150W/ch |
| Output sound pressure level | 91dB/2.83V/1m |
| Crossover frequency | 1.9kHz |
| Terminal | Five way binding post |
| External dimensions | Width 260x Height 620x Depth 320 mm |
| Weight | 26 kg (when packed) |
| Sold Separately | Speaker Stand 902 (¥ 12,000) |