Infinity RS-1 (1980)

At 176.5 kilograms, it doesn’t just fill a room with sound—it redefines the space itself.

Overview

The Infinity RS-1 (Reference Standard I) isn’t just another floorstanding speaker—it’s a statement in acoustic engineering, released in 1980 as a more accessible counterpart to the legendary IRS series. Designed to bring point-source theory into real-world living environments, the RS-1 stands 1.5 meters tall, making it imposing yet feasible for domestic installation. Where the IRS aimed for uncompromised scale, the RS-1 refined that vision into a system that could deliver IRS-level coherence without requiring a dedicated listening hall. It was marketed as a four-tower system: two dedicated woofer columns and two mid/high-range columns, paired with a channel divider (crossover), forming a 5-way, 17-driver configuration. At its Japanese launch, the system carried a price of ¥2,200,000—steep even for its time—positioning it firmly in the high-end tier.

Owners report that the RS-1’s design philosophy centers on minimizing diffraction and maximizing spherical wavefront reproduction. To achieve this, Infinity employed gently curved diffraction wings made of thick solid oak, which help smooth off-axis response by reducing interference between direct and reflected waves. The system operates on bidirectional principles in the mid and high frequencies, radiating sound from both front and rear baffles to simulate a more natural, omnidirectional dispersion pattern. This, combined with a vertical array that narrows the effective radiating area at higher frequencies, aims to collapse the soundstage into a single, precise acoustic origin—what Infinity described as “pin-point sound localization” and “3-dimensional sound field reproducibility.”

Despite its complexity, the RS-1 was engineered for practicality. It inherited the IRS’s point-source theory but scaled it down physically and financially. The woofer columns use six 20 cm polypropylene cone drivers arranged in tandem, each benefiting from a newly developed servo sensing network that extends low-frequency response with tight control. Polypropylene was chosen for its mechanical advantages: low Q (7–9), high Young’s modulus, resistance to heat (up to 135°C), and immunity to humidity—critical for long-term stability in real-world environments. The midrange and high-frequency sections rely on EMIM (Electromagnetic Induction Midrange) and EMIT (Electromagnetic Induction Tweeter) drivers, which use ultra-thin plastic diaphragms fully suspended in strong samarium-cobalt magnetic fields, enabling full-surface drive without traditional voice coils. This design avoids the mass and nonlinearity of conventional domes or cones, allowing for rapid transient response and wide bandwidth.

Specifications

Key Features

Four-Tower System with Dedicated Woofer Columns

The RS-1 breaks from conventional speaker design by separating its bass and mid/high-frequency drivers into distinct towers. Two standalone woofer units, each housing three 20 cm polypropylene cone drivers in a vertical array, handle low frequencies with servo-assisted control. This physical separation reduces cabinet resonance and allows for strategic room placement—owners often report staggering or spacing the bass columns to optimize modal distribution. The dual mid/high columns, significantly wider at 600 mm, house the EMIM and EMIT drivers in a vertical line, aligning their acoustic centers to reinforce the point-source illusion. This modular approach demands more floor space but offers superior control over bass energy and imaging precision.

EMIM and EMIT Transducers with Full-Surface Magnetic Drive

At the heart of the RS-1’s clarity lies its exotic driver technology. The EMIM (Electromagnetic Induction Midrange) uses an ultra-thin, etched plastic diaphragm suspended between powerful samarium-cobalt magnets, eliminating the need for a traditional voice coil. This results in near-massless movement, enabling the driver to respond to transients with speed unattainable by cone or dome types. Six EMIMs cover the 140 Hz to 700 Hz band, with the top unit handling 700 Hz to 3 kHz. The EMIT tweeters—three in front, one in rear—operate from 3 kHz to 8 kHz, while the Super EMIT takes over above 8 kHz. These drivers are bidirectional, radiating sound to both front and back, enhancing spatial realism. The EMIT’s 1.5-inch-wide radiating surface provides excellent horizontal dispersion, maintaining response within -2 dB at 20 kHz even at 60° off-axis.

Servo-Controlled Woofer with Polypropylene Cones

The low-frequency section relies on six 20 cm polypropylene cone drivers arranged in tandem within each woofer column. Unlike paper cones, which typically have Q values of 90–100, polypropylene’s Q of just 7–9 ensures minimal resonance and superior damping. Combined with high Young’s modulus, this material resists cone flexure under high transient loads, reducing distortion. The servo sensing network monitors cone movement and corrects driver behavior in real time, enabling flat response down to 25 Hz. This system demands robust amplification—Infinity specified 150W/ch or more for the woofer channels—and cautioned against using bridged or tube amplifiers, which could destabilize the servo loop.

Bidirectional Radiation and Diffraction Wing Design

To achieve a more natural soundfield, the RS-1 emits mid and high frequencies from both front and rear baffles, creating a dipole-like radiation pattern that mimics the way instruments radiate sound in space. This bidirectionality, combined with the gently curved diffraction wings made of solid oak, reduces edge diffraction and comb filtering. The wings act as acoustic lenses, smoothing the transition between direct and reflected sound. The entire array is designed so that, at the listening position, the energy from all drivers appears to originate from a single point—most notably aligned with the Super EMIT and top EMIM—achieving a cohesive, holographic image despite the system’s physical size.

Dedicated Active Crossover and Bi-Amplification Requirement

The RS-1 is not a passive speaker in the traditional sense. It requires a dedicated channel divider (crossover) and bi-amplification: one amplifier for the woofer columns (150W/ch minimum), another for the mid/high columns (100W/ch minimum). The crossover operates at 140 Hz, 700 Hz, 3 kHz, and 8 kHz, routing signals to the appropriate drivers with precision. This active architecture allows for tighter control over driver behavior, especially critical for the servo-woofers. Forum discussions confirm the crossover unit is prone to op-amp failures over time—owners note that Bill Watkins, Infinity’s co-founder, reportedly identified this as the most common failure point. Schematics have surfaced online, aiding restorations, but original service parts are scarce.

Historical Context

The RS-1 emerged in 1980 as the flagship of Infinity’s Reference Standard series, which included the RS 2, RS 3, RS 4.5, and later models. It was positioned as a scaled-down version of the IRS V, inheriting its point-source and bidirectional design principles but in a form factor suitable for residential spaces. At the time, few manufacturers attempted such a radical departure from conventional box speakers, and the RS-1 stood out for its scientific rigor and acoustic ambition. It was the first four-tower system Infinity produced, setting a template for future high-end designs. The RS-II, introduced later, was explicitly designed as a smaller, lower-cost alternative, underscoring the RS-1’s role as a technological benchmark.

Collectibility & Value

The RS-1 is rare on the secondary market, and complete systems—especially with the crossover unit—are even rarer. One Reddit user reported purchasing a pair of RS-1s at a thrift store for $24, though it’s unclear if the full four-tower system was included. Given the complexity and age, functional units are uncommon; the active crossover’s reliance on op-amps makes it vulnerable to decades of thermal cycling and component drift. Owners attempting restoration are advised to check power supply rails and replace aging electrolytics. Despite these challenges, those who have heard a properly restored RS-1 often describe it as revelatory—“spectacularly good,” in one owner’s words, with “pin-point” imaging and expansive dynamics. Its status as the first Reference Standard speaker to bring IRS-level performance into domestic spaces ensures its place in high-end audio history.

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