Marantz AR-3a

The AR-3a was not made by Marantz. It was manufactured by Acoustic Research (AR), a completely separate company. A Marantz speaker with this name doesn't exist in the documented record. This page covers the Acoustic Research AR-3a, which occasionally appeared in systems alongside Marantz electronics.

The AR-3a was a 3-way acoustic suspension loudspeaker produced from roughly 1967 to 1974, succeeding the AR-3. It used a 12-inch woofer in a sealed enclosure, plus early dome drivers: a 1.25-inch dome midrange and a 0.75-inch dome tweeter. The design goal was flat, accurate response in a real room, and the speaker was widely adopted as a reference monitor in university and laboratory listening tests during the late 1960s. It was the top model in AR's line, sitting above the smaller AR-2ax and AR-4x, and was replaced by the AR-11 in 1974.

The speaker was notably inefficient, with sensitivity around 85 dB / 2.83V / 1m and a 4-ohm impedance, meaning it wanted substantial clean amplifier power. Frequency response was rated at 38 Hz–20 kHz ±3 dB, with crossover points at 575 Hz and 5,000 Hz. Cabinets were finished in real wood veneers — walnut, teak, rosewood — and the whole thing weighed roughly 50–55 lbs. Audio (March 1969, p.57) featured a reader's system built around a pair of AR-3a speakers in varnished walnut driven by a Marantz Model 15 amplifier and Model 7T preamplifier — a pairing that shows up repeatedly in period photos and ads, which may be the source of the confusion between the two brands.

Original pricing is conflicting in the record, with $195 and $225 per speaker both appearing, so take either figure with caution. The AR-3a remains highly collectible, with pairs typically changing hands in the $500-$1,500 range depending on condition and veneer. Common restoration issues include aged crossover capacitors, scratchy L-pad level controls, and hardening of driver surrounds. Original midrange and tweeter diaphragms are hard to find and expensive.

Known specifications: