PAIR of Acoustic Research AR2AX Speakers – TESTED, Sound Great, SEE VIDEO. Up for sale is a pair of AR (Acoustic Research) 2ax speakers from 1973. These 3-way acoustic suspension speakers are in very good working condition. (See video) They feature a 10-inch woofer, 3.5-inch midrange, and 3/4-inch dome tweeter and are highly regarded for their warm sound. The attenuators (potentiometers) on the back of the speakers for adjusting the treble and midrange levels are working but can be a little touchy/scratchy when used. There are scratches on the oiled walnut wood case veneers especially on the bottoms as shown in the photos.