Acoustic Research AR-98LSI (1987)

A three-way floorstander tall enough to look you in the eye, built by the company that invented acoustic suspension - and quiet about it.

Overview

The AR-98LSI stands 39 inches tall and weighs 62 lbs per cabinet. It isn't a bookshelf speaker that got ambitious. It's a floorstander, 11 inches wide and 14 inches deep, and moving a pair is a two-person job. Acoustic Research introduced it in 1987 as part of the company's premium consumer lineup. The dimensions show the design brief: enough internal volume for a 10-inch woofer to do real work, without the footprint of the company's biggest boxes.

The drivers are a 10-inch woofer with foam surrounds, a 4-inch midrange, and a 1-inch dome tweeter. Crossovers are second-order networks at 500 Hz and 5 kHz. The low midrange handoff keeps the 10-inch cone out of the vocal band, and the tweeter crossover is high enough that the dome isn't asked to reproduce anything near the top of the midrange where it would beam. Sensitivity is rated at 90 dB, which is the number that matters most to anyone planning to run a pair. That's efficient enough that a wide range of amplifiers will drive them, from vintage tube designs to modern solid-state receivers, and the owner doesn't need to hunt for something with unusual gain.

Power handling is listed at up to 150W RMS per channel. Bi-wire capable terminals are fitted, so owners can run separate cabling for high and low frequencies.

One thing to flag up front, because it shows up in the documentation: the spec sheet describes the cabinet as "3-way, bass reflex (acoustic suspension)". Those two alignments are opposites in practice. The same source describes the cabinet as acoustic suspension throughout its other sections, and the bass is characterized as coming from "acoustic suspension alignment." AR's whole identity was built on the sealed-box acoustic suspension principle, and the phrasing is inconsistent, so the reflex label reads like an error in the source rather than a hybrid design. Buyers should treat the alignment as sealed acoustic suspension unless a specific unit proves otherwise.

Key Features

10-Inch Woofer with Foam Surrounds

The low end comes from a 10-inch woofer, and the surround material is the detail that matters most three-plus decades on. AR used foam surrounds here, and foam surrounds deteriorate - typically after 30 or more years. The symptoms are hard to miss: distorted bass, or a surround that visibly crumbles when touched. Re-foaming kits are widely available and the repair is well within reach of a careful hobbyist, and it restores performance without replacing the driver. Anyone buying a pair today should inspect the surrounds first. A crumbling surround means the woofer isn't being controlled properly, and running it that way risks damage that a refoam alone won't fix.

4-Inch Midrange and 1-Inch Dome Tweeter

The midrange is a 4-inch driver, and the tweeter is a 1-inch dome. The design intent, per the source material, was a clear and natural midrange, with vocals and instruments handled with precision, and a dome tweeter that stays smooth and detailed without turning harsh at higher volumes. That's the classic AR tonal target: neutrality over excitement. The sound profile is described as balanced and neutral, which makes the speaker suitable for critical listening across genres.

Second-Order Crossover at 500 Hz and 5 kHz

The crossover is a second-order network with transition points at 500 Hz and 5 kHz. Second-order slopes are a middle path. They're steeper than the simple first-order filters AR used in its earliest designs, but not so complex that the network introduces its own problems. Period coverage in High-Fidelity (September 1985, p.40) notes that the crossover networks in AR's contemporary line were modified to cut off the tweeter more rapidly at the bottom of its range, reducing distortion.

The 500 Hz point is the interesting one. It hands the midrange to the 4-inch driver relatively low, which keeps the 10-inch cone from having to reproduce the lower vocal range. Capacitors in the crossover are the other long-term wear item. They dry out or drift in value over the decades, and the symptom is a tonal balance that no longer sounds the way it should. Recapping with modern components is the standard fix and, per the source material, can significantly improve clarity and reliability.

Walnut Veneer Cabinet

The cabinet is finished in walnut veneer. Care is simple: a soft, dry cloth, and no harsh polishes. Original grille cloth may show wear after this many years, and replacement fabric is available from specialty suppliers. The dimensions are 39" × 11" × 14" (99 cm × 28 cm × 35.5 cm), which makes the AR-98LSI a genuine floorstanding speaker rather than a stand-mount. The 62 lb (28.1 kg) per-cabinet weight means it stays put.

Historical Context

The AR-98LSI arrived in 1987, during a transitional period for Acoustic Research. The company had been founded on the acoustic suspension principle developed by Dr. Edgar Villchur and Henry Kloss, and by the late 1980s it was shifting focus toward higher-end consumer models. Earlier AR designs, the AR-3 and AR-4 among them, had dominated the 1960s and 70s with a scientific approach to sound. The AR-98LSI was a modernized take on that inheritance: a three-way system with improved driver materials and a more sophisticated crossover network than the company's classic two-ways, aimed at buyers who wanted accuracy without the visual austerity of the earlier boxes.

Documentation also identifies the AR-98LSI as an improved variant of the AR-98LS, with optimized internal components and a refined crossover network intended to sharpen frequency response accuracy and soundstage depth. The two models are catalogued separately. Collectors describe the LSi version as the rarer of the pair.

Collectibility & Value

Market pricing for the AR-98LSI is genuinely inconsistent, so it's better said plainly than averaged into a comfortable number. One source puts current value at $200 - $400 per pair depending on condition, originality, and restoration quality, with a collectibility rating of 6/10. Asking prices found elsewhere run considerably higher - $1,200 and $1,500 have both been listed for pairs - though asking prices are not sale prices. The gap between the two figures is wide enough that buyers should treat any single number with caution. Grilles alone have listed in the €40 - €90 range.

The AR-98LSI is not as famous as the AR-3a, and it holds a solid rather than celebrated place among late-era AR collectors. Demand is steady, particularly from enthusiasts restoring vintage systems, and restored pairs in excellent cosmetic and sonic condition often command higher prices, especially when sold with original documentation or packaging.

On the repair side, the three recurring jobs are the ones described above: refoaming the woofer, recapping the crossover, and dealing with worn grille cloth or veneer care. Owners who have done the work describe refoaming the woofers using the shim method to keep the voice coil centered, and recapping the boards, which carry switches for the mid-bass driver. Neither job is exotic.