ONKYO Monitor 100R
¥ 109,000 (1 unit, around 1982)
Commentary
This is the world's first speaker system that successfully commercialized a magnesium alloy diaphragm.
Magnesium has a density of 1.74gr/cm2In addition, it has excellent physical properties as a diaphragm material, such as large internal loss and excellent vibration control effect.
Magnesium has a thickness of 26.5 μ m to obtain the same rigidity as titanium 20 μ m. Since the weight of magnesium is only half that of titanium, magnesium is the most suitable material for realizing a light and strong diaphragm.
In addition, compared to other metals, the damping waveform is clean and fast, and harmful peaks caused by mechanical vibration are small, so the distortion due to split vibration is less.
A 2.5 cm tweeter with an equalizer is installed in the high range.
A magnesium alloy diaphragm with a thickness of 40 μ m is used to improve frequency characteristics and power response characteristics by combining it with an equalizer developed especially for this machine.
The middle section is equipped with a composite skoker combining a magnesium alloy dome diaphragm with a diameter of φ 65 mm and a cone.
By taking advantage of the large internal loss and increasing rigidity with a sufficient thickness of 100 μ m without using a damping material inside the dome, strain is reduced.
A 32 cm cone type woofer is installed in the low range.
The diaphragm is highly rigid and shows a stable vibration mode even under Dainyu force, and uses a rotary sheet-forming cone to suppress the generation of strain.
In addition, it is driven by a 76 φ long voice coil that uses a magnet with a total magnetic flux of 258000 maxwell and an ultra-heat-resistant bobbin that withstands the high sound of 200 ℃. This realizes a woofer with a wide dynamic range and stable frequency range as well as large input.
Each unit uses an aluminum die-cast frame to prevent unwanted resonance.
The enclosure uses an acoustically excellent conifer solid board with a sufficient thickness of 25 mm for the baffle plate and 20 mm for the others. In addition, attention is paid to internal reinforcement to improve acoustic characteristics.
Equipped with independent level control for tweeter and skoker.
Model Rating
| Method | 3-way 3-speaker, bass reflex system, bookshelf type |
| Units Used | For low band : 32 cm cone type For Middle Area : 10 cm Composite Type For high-pass : 2.5 cm dome type |
| Playback frequency band | 25 Hz to 45000 Hz |
| Max Input | 150W |
| Impedance | 6 Ω |
| Output sound pressure | 90dB/W/m |
| Crossover frequency | 500 Hz, 4000 Hz |
| Cabinet internal volume | 67L |
| External dimensions | Width 430x Height 680x Depth 371 mm |
| Weight | 35kg |