SONY SS-5050II
At 20.5kg, these bookshelf cabinets carry the weight of serious engineering—not just wood and drivers, but a philosophy of control.
Overview
The SONY SS-5050II isn't a speaker that shouts for attention with flash or finish. It’s a 3-way, 3-speaker, airtight type system built for precision, not pageantry. Marketed as a bookshelf type, its 630mm height and 365mm width suggest modest placement, but the 20.5kg mass tells a different story—one of dense bracing, robust drivers, and a deliberate refusal to rattle under load. Priced at ¥52,000 around 1975, it was a statement piece for listeners who valued measured performance over spectacle. The designation as a "Legendary Product" by the Vintage Technology Archive signals its enduring reputation, though concrete details about its original reception are absent from the record.
Specifications
| Manufacturer | Sony |
| Product type | 3-Way, 3-Speaker, Airtight Type, Bookshelf Type speaker system |
| Original price | ¥ 52,000 (1 unit, around 1975) |
| Effective frequency band | 40 Hz to 20000 Hz |
| Output sound pressure level | 91dB/W/m |
| Impedance | 8 Ω |
| Maximum allowable input | 80W |
| Crossover frequency | 800 Hz, 8000 Hz |
| External dimensions | Width 365x Height 630x Depth 318 mm |
| Weight | 20.5kg |
| Low-frequency driver | 30 cm cone type |
| Midrange driver | 3.5 cm Dome Type |
| High-frequency driver | 2.5 cm dome type |
Key Features
30 cm CARBOCON Cone with Radial Carbon Fiber Edge
The low-frequency driver is the anchor of the SS-5050II’s design. Its 30 cm cone, constructed from CARBOCON—a blend of carbon fibers in a resin matrix—delivers high rigidity and low mass, critical for minimizing breakup modes and transient smearing. Sony further refined the suspension by mixing carbon fibers radially into the roll edge, a technique aimed at suppressing deformation and division vibration during large excursions. This attention to edge behavior suggests a focus on maintaining linearity even at higher volumes, where typical rubber or foam surrounds might introduce non-linearities.
High-Flux Magnetic Circuits Across All Drivers
Magnetic field strength is unusually well-documented across all three drivers, indicating a core design priority. The low-frequency unit employs a 120 mm diameter magnet producing 11,000 gauss in the air gap, while the midrange steps up to 13,000 gauss via an 110 mm magnet. The high-frequency driver pushes further, achieving 15,000 gauss. These dense fields improve motor control, reduce distortion, and enhance transient response by ensuring the voice coil operates in a strong, uniform magnetic environment.
Hard Aluminum Alloy Foil Dome Tweeter
3.5 cm Composite Midrange with Viscoelastic Damping
The midrange unit is a 3.5 cm dome type, constructed from a blend of special fibers and viscoelastic resin, then coated with a special damping agent post-molding. This layered approach targets internal resonances and breakup, aiming for a smooth, coherent transition between the woofer and tweeter. The 13,000 gauss magnetic circuit further ensures tight control over this critical frequency band, where even minor distortions are easily perceived.
Long Travel Voice Coil Drive System
The inclusion of a long travel voice coil system indicates that the SS-5050II was designed for dynamic range, not just fidelity at moderate levels. This allows the 30 cm woofer to maintain linearity during deep bass passages, supporting the 40 Hz low-end claim without requiring excessive cabinet volume. The 50 mm bobbin, wound with heat-resistant treated wire, suggests an effort to manage thermal compression during sustained high-power operation.
Collectibility & Value
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