AR(Acoustic Research) AR-9
¥ 278,000 (1 unit, around 1980)
Commentary
This is a large tall boy speaker system of the vertical series designed with sufficient consideration for high-output power amplifier.
Two 30-cm cone woofers are placed on both sides of the enclosure and a crossover frequency of 200 Hz eliminates the wall-dip phenomenon that occurs between the speaker and the back wall.
It is equipped with 20 cm cone type units for the middle and low band, 3.8 cm dome type units for the middle and high band, and 1.9 cm dome type units for the high band.
The mid - and low-range units are mounted in subenclosures to prevent internal interference.
In addition, a magnetic colloidal magnetic flux developed by NASA is inserted between the voice coil and yoke of the mid-range and high-range units to reduce distortion and improve input resistance with a structure that does not deviate from the central axis.
The network section is equipped with an electronic automatic transmission originally developed for low-frequency use.
Like the mission of an automatic car, this system automatically controls the low-frequency characteristics electrically. It operates so that the damping is maximized at the resonance frequency without reducing the low-frequency output. For the portion exceeding the resonance frequency, it is switched electrically so that the flat characteristics are maintained even if the signal exceeds the bus spectrum.
In addition, a 17 AWG air-core coil, a computer-grade electrolytic capacitor, and a high input resistance ceramic resistor are used as elements.
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.
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Model Rating
| Method | 4-Way, 5-Speaker, Acoustic Suspension System, Tall Boy Type |
| Units Used | For low band : 30 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 | 18 Hz to 30 kHz |
| Low reproduction frequency | 28Hz -3dB |
| System Q | 0.5 |
| Output sound pressure level | 87dB/W/m |
| Impedance | 4 Ω (minimum 3.2 Ω) |
| Continuous maximum input | 175W |
| Max Input | 400W |
| Crossover frequency | 200 Hz, 1.2 kHz, 7 kHz |
| Level control | Low : Automatic Medium and low frequency : 3-step switching Mid-High : 3-Step Switching High frequency : 3-step switching |
| Internal volume | 120L |
| External dimensions | Width 381x Height 1340x Depth 402 mm |
| Weight | 59kg |