Oehlbach Bi-Tech 4

The Bi-Tech 4 by Oehlbach redefines high-fidelity cabling standards by offering a particularly refined technical approach to bi-wiring. This European cable, sold by the meter, is aimed at demanding audiophiles who want to optimize the performance of their dual-terminal speakers. With its dual-conductor design using specialized materials for different frequencies, it promises to unlock the sonic potential of the most ambitious hi-fi systems.

Innovative Technical Architecture

The Bi-Tech 4 adopts a technical philosophy rarely seen in the industry: adapting the conductor to the frequency being transmitted. This approach is realized through a dual architecture using 2 x 2.5 mm² silver-plated copper (SPC/OFC) for mid and high frequencies, coupled with 2 x 4.0 mm² oxygen-free copper (OFC) for low frequencies.

This differentiation is based on the physical properties of audio signal propagation. High frequencies, which travel mainly on the surface of conductors (skin effect), benefit from silver plating that optimizes their transmission. Low frequencies, which require more “material” to be carried without loss, take advantage of the generous 4 mm² section of high-purity OFC copper.

The cable’s round geometry makes installation easy while maintaining optimal separation between the different conductors. This design helps prevent unwanted interactions between the treble and bass paths, thus preserving the clarity and definition of each frequency range.

Exceptional Materials and European Craftsmanship

Oehlbach relies on premium materials to guarantee the performance of the Bi-Tech 4. The oxygen-free copper (OFC) used for the bass features a particularly homogeneous crystalline structure, limiting grain interactions and reducing distortion. This structural purity results in more defined bass and improved transient control.

The silver-plated copper (SPC) used for the mid and high-frequency conductors leverages the exceptional conductivity of silver while retaining the mechanical strength of copper. This technical solution offers the sonic benefits of a solid silver cable without the cost and flexibility constraints.

The transparent polymer outer sheath provides effective protection against electromagnetic interference while maintaining remarkable flexibility. This feature greatly facilitates installation, even in complex setups where the cable must navigate tight spaces or sharp bends.

Principle and Benefits of Bi-Wiring

Bi-wiring involves using two separate cables to power the woofers and the midrange/tweeters of a speaker, instead of the traditional metal jumper. This technique physically separates the electrical paths of the different frequency bands, reducing interactions and improving overall definition.

The Bi-Tech 4 takes this logic further by optimizing each conductor for its dedicated frequency band. The energy-hungry bass is handled by the 4 mm² section, ensuring minimal resistance and optimal damping factor. The mid and high frequencies benefit from the silver plating, which preserves the finest details and spatialization.

This approach results in a more open soundstage, more natural timbres, and better instrument separation. Attacks are sharper, decays smoother, and the overall sound gains in coherence and musicality.

Installation and System Compatibility

The Bi-Tech 4 requires speakers equipped with dual terminals (separate A/B connections). This configuration, found on most high-end floorstanding speakers, allows you to remove the original metal jumpers and enable bi-wiring.

Installation is straightforward: simply connect the 4 mm² conductors to the bass terminals and the 2.5 mm² conductors to the treble terminals of each speaker. On the amplifier side, the four conductors are connected as usual to the positive and negative outputs of each channel.

With a power handling capacity of up to 350 watts per channel, it can be used with powerful amplifiers, including high-powered tube models. This generous margin ensures safe operation even with demanding dynamics and speakers.

Technical Specifications

Physical Specifications

• Type: bi-wiring speaker cable
• Conductor cross-section: 2 x 2.5 mm² + 2 x 4.0 mm²
• Geometry: round shape
• Materials:
  • Conductors: oxygen-free copper (OFC) + silver-plated copper (SPC / OFC)
  • Sheath: plastic
• Length: 50-meter spool

Electrical Specifications

• Supported power: up to 400 W
• Signal direction: IN / OUT

Audio Performance

• Optimized transmission for bi-wiring:
  • 2.5 mm² for mid/high frequencies (silver-plated copper)
  • 4.0 mm² for low frequencies (OFC copper)
• Natural, detailed, and powerful sound, with refined highs and dynamic bass
• Exceptional flexibility thanks to the use of premium materials