Infinity RS-6 (1982?)

A floorstanding speaker from Infinity's Kappa era - sealed, with an EMIT tweeter and serious low end for its time

Overview

The Infinity RS-6 was the top model in the New RS series and part of the Kappa family. It is a tall, sealed floorstander from the mid-1980s. The naming gets murky fast. It shows up as the RS-6, RS-6 Kappa, RS-6001 and RS-6B, and owners report seeing all of them. Whether they reflect revisions, regional differences or marketing tweaks remains unclear. The build is clear enough: a 3-way, floor-standing "Tall Boy" design with an airtight sealed enclosure instead of ported bass. Many makers were chasing boom at the time, and Infinity went for precision, extension and coherence.

This was high-end gear. Inside it has Monster cable, and the crossover uses polypropylene capacitors like Solen. It was built to be paired with serious amplification and handle up to 150 watts. Frequency response stretches to 45 kHz, well beyond human hearing, which hints at a design tuned for transient accuracy and air. According to available documentation, the RS-6B variant was introduced in 1984 and discontinued in 1986, which puts the model in the middle of the Kappa era.

Key Features

EMIT-K Tweeter: The Crown Jewel

The tweeter is the EMIT-K (Electro Magnetic Induction Tweeter), with a Kapton diaphragm and a neodymium magnet in a push-pull configuration. EMIT was Infinity's answer to the limits of traditional soft domes, aiming for lower distortion and faster transient response. The push-pull design cancels out magnetic non-linearities, and the neodymium keeps the motor structure compact and powerful. Owners report the highs as "great," with a sense of openness that doesn't scream "vintage harshness." Some units were later restored with Polydome K tweeters. That suggests the original EMIT-K units may degrade or need replacement after decades of use.

Midrange Clarity via Dome Design

Between the woofer and tweeter sits a dome midrange driver with a polypropylene/graphite composite diaphragm. It's a dome, not a cone, so you get the dispersion of a dome with the stiffness of a reinforced material. The crossover point is 800 Hz, where vocals and instruments are handed to the midrange. Combined with the sealed cabinet, this avoids the colorations that can plague ported mid-bass regions. The midrange is described as "very good," with a natural presence that keeps voices and acoustic instruments front and center.

IMG Woofer: Stiff, Light, and Fast

The 8-inch (20cm) woofer uses an IMG (Injection Mold Graphite) diaphragm, which is polypropylene reinforced with graphite fiber. That combination is stiff without adding mass, so the cone can start and stop quickly and smear less. In a sealed cabinet tuned for accuracy rather than bass quantity, that is what you want. Despite being "only" an 8-inch driver, owners note it "goes pretty low," likely due to the cabinet tuning and driver control. Frequency response reportedly extends down to 39 Hz, which is impressive for a non-ported design of this size. Some versions, such as the RS-6/B, used polypropylene cones and dual voice coil 8-inch woofers rated at 4 ohms, so the bass driver varied across the RS-6 family.

Sealed Cabinet with Round Baffle

Infinity chose a sealed (airtight) enclosure, which trades efficiency for tighter, more time-aligned bass. The cabinet is high-density particleboard. The front baffle is rounded to reduce edge diffraction, which you don't see often in speakers of this era. The round baffle helps smooth the off-axis response and contributes to a more coherent soundstage. With no rear port, you can place these closer to walls without boundary reinforcement messing with the tuning.

High-End Internal Execution

Inside, the RS-6 doesn't cut corners. The crossover uses polypropylene capacitors, with Solen noted as one example, and "optimal Q" inductors. The internal wiring is Monster cable, which was a premium choice at the time. There's also a level control, likely for the tweeter or midrange, so owners can adjust the voicing to their room or preference. The crossover for the RS-6/B variant (part number #716-0347) is now listed as NLA ("No Longer Available"), which makes repairs and replacements difficult.

Historical Context

The RS-6 came out while Infinity was building its reputation for high-performance, technically advanced loudspeakers. It was the flagship of the New RS series and a member of the Kappa family. The sealed design ran against the ported trends of the time and appealed to listeners who valued timing and clarity over raw output. HiFi-Stereo (November 1983, p.47) noted that the three drivers were mounted in a vertical line and that the speaker could be operated vertically or mounted horizontally on a shelf. That gives some flexibility in placement for a floorstander.

Collectibility & Value

The RS-6 isn't a unicorn, but it's not common. Pairs show up on the used market from time to time, with prices ranging from €125 up to €650 or $399, depending on condition, finish (natural oak vs. wood-grain print), and whether they've been serviced. The higher end of that range likely reflects well-maintained or restored units, especially those with recapped crossovers or refoamed woofers. Fully restored RS-6 Kappa models have listed at $699 on Reverb.

Maintenance is predictable for a speaker this age. The 8-inch woofer surrounds may need refoaming. That's a standard procedure that can restore punch and eliminate rattles, and YouTube repair videos confirm it as a common need for the 1984 RS-6/B. The crossover capacitors were high-quality to begin with but are still decades old. Owners report that recapping can sometimes improve performance, bringing back clarity and dynamics. The level controls (if present) may need cleaning if they've gotten noisy. Since the crossover for the RS-6/B is now NLA, sourcing replacements or building equivalents may be necessary.

There's also an optional stand, the RS-6PED, sold separately. It positions the speakers correctly and helps avoid floor reflections muddying the bass.

The lack of a definitive line between the RS-6, RS-6B and RS-6001 doesn't bother owners. One reports loving the sound in their living room. Another says they "sound really good" with strong bass, excellent midrange, and a top end that delivers.