JBL S106 Aquarius II

You don't find many of these. When you do, it looks like a prototype from a version of JBL that went all-in on hand-built audiophile speakers.

Overview

The JBL S106 Aquarius II is very rare. This 3-way loudspeaker system came out of a short stretch when JBL built ultra-low-volume, hand-assembled audiophile speakers under the Aquarius name. Very few were made. Those that survive are described as "Extraordinary and Nearly Extinct." These weren't mass-market floorstanders. The craftsmanship was so labor-intensive that the speakers never had a real shot at a showroom.

The S106 was built for precision, not for the rugged, tour-ready duty JBL was known for. Every unit needed hand-picked drivers, especially the midrange units, which JBL engineers individually selected to meet tight performance tolerances. The cabinets and hardware were handmade, which made production prohibitively expensive. It wasn't a cost-effective product. It was an experiment in what JBL could build with commercial constraints lifted. Collectors describe it as "Very Rare" and "Rarest of the Rare," and even dedicated JBL archives barely acknowledge it.

Specifications

Manufacturer	JBL
Model	S106 Aquarius II
Type	3-Way Loudspeaker System
Drivers	One LE20 HF, two LE5 Mids, one 123 Woofer
Weight	about 80 lbs
Ship Weight	90 lbs
Impedance	8 ohms
Power handling	100 watts
Frequency response	70Hz - 20kHz
Sensitivity	90 dB

Key Features

Three-Way Driver Array with Precision Matching

The S106 Aquarius II uses a three-way configuration: one LE20 high-frequency driver, two LE5 midrange units, and a single 123 woofer (a 12-inch driver). Dual midrange drivers are unusual for the era and suggest a focus on midband clarity and dispersion. The LE5 units were hand-picked by JBL engineers to ensure consistent performance. That practice was more common in studio monitors or high-end European designs than in American-made speakers of the time. The design points toward critical listening, where tonal balance and phase coherence mattered more than efficiency or ease of production.

Handmade Cabinet with Acoustic Optimization

The cabinet is described as "Extremely Well designed," likely due to its sealed enclosure, which offers tighter bass control than ported systems. It was constructed by hand, so it avoids the cost-cutting shortcuts typical of mass production. The exact materials aren't specified, but the handmade cabinets and hardware point to a build quality well beyond JBL's mainstream offerings. The enclosure is meant to minimize resonance and internal reflections, which matters for a complex three-way crossover and multi-driver array.

Rear Deflection Panel with Diffraction Control

The most visually striking feature is the rear-mounted "deflection panel," which houses the two LE5 midrange drivers and the 123 woofer. The panel includes "wild looking diffraction cones and brackets," which suggests an advanced approach to managing rear wave propagation and minimizing interference. By containing and shaping the rear output of the mid and low-frequency drivers, JBL may have been aiming to improve imaging stability and reduce cabinet coloration. Those techniques are more common in research-grade or studio monitors than consumer loudspeakers. The high-frequency driver is the only one on the front baffle, which points to controlled wave launch and time alignment.

Historical Context

The JBL S106 Aquarius II belongs to the Aquarius line, a short-lived series that included Models 1, 2, 2A, 3, and 4 around 1970. Unlike JBL's commercial speaker lines, the Aquarius series appears to have been a boutique experiment, possibly conceived under the influence of James B. Lansing's original design ethos, where performance trumped profitability. The S106 was not viable for mass production because of its hand-picked drivers and handmade cabinets, which drove costs too high for the consumer market. As one account puts it, production was limited "due to the way James designed them." These were not living room speakers. They were described as auditorium speakers, built for large spaces and critical listening environments.

Collectibility & Value

Today the S106 Aquarius II is among the most elusive JBL models in existence. It is described as "Very Rare" and "Nearly Extinct." A pair was listed for $475 in 2010, though the cabinets showed "dings, chips, and scratches." More recent listings show a sharp increase in collector interest: €1,800 in 2019, $2,564 in 2024, and a $4,999 listing on Reverb in 2024. Condition, provenance, and buyer awareness heavily influence price. Sellers consistently note "some cosmetic wear but are in good working condition." There are no documented common failures or repair paths, so maintenance is likely a bespoke job. With the handmade construction and no service documentation, restoration would be a project for the deeply committed.

Market Value

┌──────────────────────────────────────────────────────────────────────────┐
│ JBL S106                                                        Aug 2026 │
├──────────────────────────────────────────────────────────────────────────┤
│ High      $157                                    Latest            $157 │
│ Median    $102                                    Trend                — │
│ Low       $78                                     Volume           ~1/mo │
├──────────────────────────────────────────────────────────────────────────┤
│   $200 ┤                                                                 │
│        │                                                                 │
│        │                                                                 │
│   $136 ┤                                                                .│
│        │                                                                 │
│        │            .                                                    │
│        │.                                               .                │
│    $50 ┤                                                                 │
│        ├─────────────────────────────────────────────────────────────────│
│    vol │█           █                                   █               █│
│        └─────────────────────────────────────────────────────────────────│
│         2026-03                      2026-05                      2026-07│
└──────────────────────────────────────────────────────────────────────────┘

eBay completed sales. Excludes accessories, parts, and non-working units. Hover points for details.