hifi engine

Manual Library / Acoustic Research

Acoustic Research AR-9

4-Way Floor-Standing Loudspeaker System (1979)

add a review add a review

Acoustic Research AR-9


In the Acoustic Research AR-9, for the first time we have a system that is virtually flat down to 28Hz, comes in with a more than acceptably low Q of 5, and reproduces bass frequencies with startling power and clarity.

How have AR engineers managed to bend the laws of physics?

First, the AR9 uses two 300mm (12 inch) woofers connected in parallel. At any volume setting each of them moves only half the distance a single driver would have to move to produce the same volume level. Thus the woofers are able to handle more power without distortion or break-up.

Second, a large enclosure (120 litres) is used to create a system with a low resonant frequency.

Third, and the real secret weapon, is a sophisticated new crossover network - an important step ahead in speaker design. This crossover is designed with special circuitry that acts like an automatic transmission and helps control bass response. It allows the system to have maximum damping at the resonant frequency (thus low Q) while maintaining bass output. Above the resonant frequency it shifts electronically to maintain flat response across the bass spectrum.


Type: 4 way, 5 driver loudspeaker system

Frequency Response: 18Hz to 30kHz

Power Handling: 175W

Recommended Amplifier: 400W (maximum)

Crossover Frequency: 200, 1200, 7000Hz

Impedance: 4Ω

Sensitivity: 87dB

Bass: 2 x 300mm acoustic suspension

Midbass: 1 x 200mm acoustic suspension

Midrange: 1 x 38mm dome

Tweeter: 1 x 19mm dome

Dimensions: 1340 x 381 x 402mm

Weight: 59kg


Related Catalogues

Truth in Listening

If you have any problems opening files please read the download FAQ. All files are provided under strict licence and reproduction without prior permission or for financial gain is strictly prohibited.

If you have additional documentation please consider donating a copy to our free archive.


re: AR-9

It has two Bass: 2 x 300mm acoustic suspension on the sides

re: AR-9

Have AR9 40 years. Still a dream.

This website is not affiliated with or sponsored by Acoustic Research. To purchase AR-9 spares or accessories, please contact the company via their website or visit an authorised retailer.