AR-58s (1978–1980s)
A passive bookshelf speaker from Acoustic Research, sharing driver technology with the AR-9L series and featuring a 12" square-magnet woofer.
Overview
The AR-58s is a passive loudspeaker system made by Acoustic Research in the late 1970s and into the 1980s. Assembly drawings are dated as early as April 1978, and components have been seen with date codes from 1983. It was marketed as a streamlined model in the AR-58 line, and it uses an acoustic suspension design. The woofer is 12 inches with a square magnet structure, originally developed for the AR-XXs and AR-XXLS series. The midrange driver is shared with the AR-9, AR-90, and AR-92. It is sometimes called a bookshelf speaker, but its size and driver complement suggest a larger footprint. Market listings often group it with floor-standing models like the AR-91, which it is considered equivalent to in performance and design.
Design
The AR-58s was among the first models to use a driver design later used in the AR-9L, so the engineering is shared. It has a 12" square-magnet woofer and a dome midrange driver (model MM-2044). Both can be serviced with available replacement parts, such as the FSK-11AR woofer repair kit. The cabinets are typically finished in the vinyl wood grain common to the era, and original grills are reported to be intact on surviving pairs. The system is passive, with no active electronics or powered components.
Market
The AR-58s was originally priced at $325 per pair in 1982 High Fidelity (June 1982). Collector interest has been steady. Recent asking prices reached $600 for a pair as of October 2025, though actual sales have been reported around $500. Shipping weight for a pair is listed at 100 pounds, which suggests substantial cabinet construction. No widespread failure modes are documented, but some users have noted a potential dip in frequency response. Driver refurbishment is possible through third-party parts. Enthusiast discussions mention it alongside the Klipsch Chorus 2, JBL L100, and Boston Acoustics A400.
eBay Listings
As an eBay Partner, we earn from qualifying purchases. This helps support our independent vintage technology research.