Shinjitsu Classic SA12 - CP750ND (First-Run)
SA12 – Large Format 96 dB Horn Speaker
Why This Speaker Exists
The problem: Large single woofers can deliver stunning bass, but only when they aren’t asked to reproduce the entire midrange as well. When a big cone must move far for bass and simultaneously provide musical detail, the midrange becomes less clean — not by design, but by physics.
Why it happens: A 12-inch woofer excels at bass because of its size and air-moving ability. But midrange clarity requires delicacy, very small movements, and fast settling. When a cone is asked to do two opposite jobs at once, detail can soften simply because the driver is working too hard to do both.
Our solution: The SA12 crosses its woofer over at approximately 800 Hz, handing off nearly the entire midrange and treble to a Beyma CP755Nd compression driver on a constant-directivity horn. This horn is engineered with a specialized high-frequency throat insert that boosts extension and smoothness, allowing it to cover multiple octaves effortlessly. With the horn carrying the majority of the spectrum, the woofer is free to do what it does best: powerful, controlled bass.
Your result: Deep, authoritative low end from the woofer — and open, articulate, immediate mids and highs from the horn. The entire presentation feels effortless, full-scale, and alive at any volume, even with single-digit-watt amplifiers.
How It Sounds
- Effortless scale — a big, room-filling soundstage with lifelike projection.
- Fast, uncompressed midrange — horn-driven clarity that remains composed at all levels.
- Natural, extended highs — smooth treble from the horn’s enhanced throat geometry.
- High efficiency — ideal for low-power SET, Class A, and high-current solid-state amplifiers.
Highlights
- Horn Coverage: ~800 Hz – 20 kHz (no tweeter required)
- Compression Driver: 2″ Beyma CP755Nd — polymer-suspended titanium diaphragm
- Horn: Beyma TD460N — constant-directivity design with high-frequency enhancement throat
- Woofer: 12″ large-format driver for deep, controlled bass
- Crossover: Fully passive, 2nd-order high-pass & low-pass
- Adjustability: Front-mounted L-Pad for fine treble balance
- Cabinet: ¾″ Baltic Birch — rabbet-joined, braced, and acoustically inert
- Composite Support System: In-house 3D-printed cradle & backplates for optimized damping
Digitally-Engineered Composite Components
Every Shinjitsu Audio product — including the SA12 — uses precision 3D-printed polymer components where they outperform traditional materials. These composite elements provide stable, low-resonance support that enhances clarity and reduces cabinet-borne noise.
Each cradle, mount, and structural insert is CAD-designed and printed to engineered tolerances, giving consistent performance across every pair we ship.
This is the same modern manufacturing approach used by companies like KEF, Wilson Benesch, and Vivid Audio — chosen because it simply works better.
Specifications
| System | Horn-loaded 2-way (800 Hz crossover) |
| Sensitivity | 96 dB (1W / 1m) |
| Nominal Impedance | 8 Ω |
| Crossover | Internal 2nd-order (HP/LP) |
| Height | 43.5″ (110.5 cm) |
| Width | 17″ (43.2 cm) |
| Depth | 15.5″ (39.3 cm) |
| Weight | 75 lb (34 kg) |
Cabinet Construction & Joinery
All Shinjitsu Audio speaker cabinets are made from ¾″ Baltic Birch plywood — never MDF. Its 13-ply structure offers superior strength, resonance control, and longevity.
Rabbet Joint Strength
- Increased glue surface for exceptional bonding
- Mechanical interlock keeps panels aligned and rigid
- Self-registering for precise, repeatable construction
- Used in fine cabinetry and premium audio enclosures
End grain is intentionally visible — a hallmark of real joinery.
Why We Don’t Use Veneer
Veneer is thin (~0.5 mm), fragile, and difficult to repair. Baltic Birch’s 1.5 mm outer ply is stronger, refinishable, and far more durable.