Infinity RS-1 (1980)

At 176.5 kilograms, it fills a room with sound and changes how the space behaves.

Overview

The Infinity RS-1 (Reference Standard I) is a floorstanding speaker released in 1980 as a more accessible counterpart to the IRS series. It was designed to bring point-source theory into real living rooms. The RS-1 stands 1.5 meters tall, which is imposing but workable for a home. The IRS aimed for uncompromised scale. The RS-1 pulled that idea down to a system that could deliver IRS-level coherence without a dedicated listening hall. It was marketed as a four-tower system: two woofer columns and two mid/high-range columns, plus a channel divider (crossover). That adds up to a 5-way, 17-driver configuration. At its Japanese launch it cost ¥2,200,000, steep even for its time, and it sat firmly in the high-end tier.

Owners report that the RS-1's design centers on minimizing diffraction and maximizing spherical wavefront reproduction. Infinity used gently curved diffraction wings made of thick solid oak, which smooth off-axis response by reducing interference between direct and reflected waves. The mid and high frequencies work on bidirectional principles. Sound radiates from both front and rear baffles to simulate a more natural, omnidirectional dispersion pattern. A vertical array narrows the effective radiating area at higher frequencies. Together these aim to collapse the soundstage into a single, precise acoustic origin. Infinity described this as "pin-point sound localization" and "3-dimensional sound field reproducibility."

Despite the 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 benefits from a newly developed servo sensing network that extends low-frequency response with tight control. Polypropylene was chosen for its low Q (7-9), high Young's modulus, resistance to heat (up to 135°C), and immunity to humidity, all useful for long-term stability. The midrange and high-frequency sections use EMIM (Electromagnetic Induction Midrange) and EMIT (Electromagnetic Induction Tweeter) drivers. These have ultra-thin plastic diaphragms fully suspended in strong samarium-cobalt magnetic fields, so the whole surface is driven without a traditional voice coil. That avoids the mass and nonlinearity of conventional domes or cones, and gives rapid transient response and wide bandwidth.

Specifications

Manufacturer	Infinity
Model	RS-1 (Reference Standard I)
Product type	speaker system (floor type)
Model Rating Method	5-way, 17-speaker floor type
System	consists of four units (two woofer units and two mid-range units) and a channel divider
Units Used - For low band	20 cm cone x6
Units Used - For mid-low band	6 EMIM models
Units Used - For Middle and High Range	EMIM Type x1
Units Used - For High Frequency	EMIT Type x3
Units Used - For Super High Range	Super EMIT x1
Frequency band	25 Hz to 32 kHz ± 2 dB
Impedance	3 Ω
Crossover frequency	140 Hz, 700 Hz, 3 kHz, 8 kHz
Recommended amplifier - Woofer unit	150W/ch or more
Recommended amplifier - Mid-range / Tweeter	100W/ch or more (bi-amplifier system)
External dimensions - Woofer unit	360 mm wide x 1,500 mm high x 360 mm deep
External dimensions - Midrange / Tweeter	W 600x H 1,500x D 600 mm
System weight	Approx. 176.5 kg (total weight)

Key Features

Four-Tower System with Dedicated Woofer Columns

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

EMIM and EMIT Transducers with Full-Surface Magnetic Drive

The EMIM (Electromagnetic Induction Midrange) uses an ultra-thin, etched plastic diaphragm suspended between powerful samarium-cobalt magnets, with no traditional voice coil. The movement is near-massless, so the driver responds to transients faster than cone or dome types can. Six EMIMs cover the 140 Hz to 700 Hz band, and the top unit handles 700 Hz to 3 kHz. The EMIT tweeters, three in front and one in rear, operate from 3 kHz to 8 kHz. The Super EMIT takes over above 8 kHz. These drivers are bidirectional and radiate sound to both front and back. The EMIT's 1.5-inch-wide radiating surface gives excellent horizontal dispersion, holding response within -2 dB at 20 kHz even at 60° off-axis.

Servo-Controlled Woofer with Polypropylene Cones

The low-frequency section uses six 20 cm polypropylene cone drivers in tandem within each woofer column. Paper cones typically have Q values of 90-100. Polypropylene's Q of just 7-9 means minimal resonance and better damping. With its high Young's modulus, the material resists cone flexure under high transient loads, which reduces distortion. The servo sensing network monitors cone movement and corrects driver behavior in real time, giving flat response down to 25 Hz. This system needs serious amplification. Infinity specified 150W/ch or more for the woofer channels and cautioned against bridged or tube amplifiers, which could destabilize the servo loop.

Bidirectional Radiation and Diffraction Wing Design

The RS-1 emits mid and high frequencies from both front and rear baffles. This creates a dipole-like radiation pattern that mimics the way instruments radiate sound in space. Combined with the gently curved solid oak diffraction wings, it reduces edge diffraction and comb filtering. The wings act as acoustic lenses and smooth the transition between direct and reflected sound. The whole array is designed so that, at the listening position, the energy from all drivers appears to come from a single point, most notably aligned with the Super EMIT and top EMIM. The result is a cohesive, holographic image despite the system's size.

Dedicated Active Crossover and Bi-Amplification Requirement

The RS-1 is not a passive speaker in the traditional sense. It needs 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 and routes signals to the appropriate drivers. This active setup gives tighter control over driver behavior, which matters most 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 and help with 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. It kept the point-source and bidirectional design principles in a form factor suited to residential spaces. Few manufacturers at the time attempted such a radical departure from conventional box speakers. It was the first four-tower system Infinity produced. The RS-II, introduced later, was explicitly designed as a smaller, lower-cost alternative.

Collectibility & Value

The RS-1 is rare on the secondary market, and complete systems, especially with the crossover unit, are rarer. One Reddit user reported buying a pair of RS-1s at a thrift store for $24, though it's unclear if the full four-tower system was included. Functional units are uncommon given the complexity and age. 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. Those who have heard a properly restored RS-1 often describe it as revelatory. One owner called it "spectacularly good," with "pin-point" imaging and expansive dynamics.