AR(Acoustic Research) AR-90
¥ 198,000 (1 unit, around 1980)
Commentary
The Tall Boy type speaker system of the Vertical Series inherits the main design of the AR-9 and achieves further miniaturization.
Two 25 cm cone type woofers are installed in the lower range, and by installing on both sides of the enclosure, low-distortion bass playback is achieved.
It has a 20 cm cone type woofer in the middle and low band like the AR-9.
The unit is mounted in a sub-enclosure to prevent mutual interference, and the vocal band of 200 Hz to 1200 Hz is received by this unit to realize natural vocal reproduction.
It is equipped with a 3.8 cm dome type unit for the middle and high range and a 1.9 cm dome type unit for the high range.
These units are also the same as the AR-9 units in the middle and low frequencies. A magnetic colloidal magnetic flux developed by NASA is inserted between the voice coil and yoke to reduce distortion and improve input resistance by making a structure that does not deviate from the central axis.
17 AWG air-core coils, computer-grade electrolytic capacitors, and non-inductive high input resistance ceramic resistors are used in the network section.
The AR traditional acoustic suspension system is used for the enclosure.
In this system, the air acts as a spring by completely sealing the inside, and compliance can be increased, and low-frequency resonance frequency can be made lower.
An acoustic blanket, a special sound-absorbing material, is installed around the driver unit to prevent deterioration of sound quality due to reflected sound.
It is finished with walnut oil.
Model Rating
| Method | 4-Way, 5-Speaker, Acoustic Suspension System, Tall Boy Type |
| Units Used | For low band : 25 cm cone x2 For middle and low band : 20 cm cone type For Middle and High Areas : 3.8 cm Dome Type For high-pass : 1.9 cm dome type |
| Frequency characteristic | 23 Hz to 30 kHz |
| Low reproduction frequency | 32Hz -3dB |
| System Q | 0.8 |
| Output sound pressure level | 87dB/W/m |
| Impedance | 4 Ω (minimum 3.2 Ω) |
| Continuous maximum input | 150W |
| Max Input | 300W |
| Crossover frequency | 200 Hz, 1.2 kHz, 7 kHz |
| Level control | Medium and low frequency : 3-step switching Mid-High : 3-Step Switching High frequency : 3-step switching |
| Internal volume | 90L |
| External dimensions | Width 368x Height 1102x Depth 386 mm |
| Weight | 37kg |