Supreme sound: QED unveils Supremus Zr – its latest next-generation flagship loudspeaker cable

British audio specialist, QED, today introduces its next-generation flagship loudspeaker cable: Supremus Zr. Developed without compromise, Supremus Zr is the result of more than five decades of technological evolution and refinement.

Featuring leading-edge QED audio innovations, the new Zr model now boasts high-quality zirconia plugs and barrels. Used in watches and fountain pens and in automotive and aerospace industries, this advanced ceramic material is prized for its durability and high resistance to wear, temperature and eddy currents. Its lustrous surface also adds a luxury finish to the cable.

In conjunction with QED’s Aircore™ and Airloc™ technologies and a host of other cutting-edge designs, Supremus Zr represents the most effective way of preserving the integrity and fidelity of the analogue music signal from beginning to end that QED has ever achieved.

Key features at a glance

  • Zirconia Airloc™ design: NEW hard-wearing zirconia barrels and boots offerdurability and resistance to performance-affecting eddy currents, in one lustrous-looking material.
  • Cold weld system unifies the conductors and plug components for a lifetime of perfect functionality.
  • Rhodium-plated locking design ensures optimal contact between a speaker binding post and the cable plug for a maintenance-free connection.
  • Aircore technology delivers an even, consistent performance across the entire audible frequency range.
  • 6.2 mm2 ultra-low resistance conductors effectively allows your amplifier to exert complete control over your speakers.
  • Cryogenic treatment ensures aperfect cable microstructure for more natural tonality.

Zirconia Airloc™ design

NEW: Zirconia barrels and boots

The exceptionally high mechanical strength of zirconia, its remarkable resistance to scratches and general wear, and its glossily lustrous finish, all make it the ideal material for this cable’s barrels and boots. Not only are the Supremus Zr plugs gleaming and tactile, the electrically inert nature of zirconia also means eddy currents cannot become established and therefore plug-induced distortion remains vanishingly low.   

Airloc™ cold weld system

Our high-pressure termination process compresses the conductors and plug together, creating a cold-welded area where conductors and plug effectively become one. Because all the air has been removed from the joint, there can be no oxidisation or degradation in conductivity – and that’s true for the entire lifetime of the cable.

Rhodium-plated locking design

Aside from its purely decorative properties – which are considerable – rhodium makes the surface of the Supremus Zr connectors very smooth, increasing the contact area and reducing resistance. Designed specifically for Supremus Zr cable, this unique contact expansion system securely clamps the rhodium-plated beryllium copper pins into the speaker terminals, while at the same time increasing the contact area of the plugs, simply by twisting the plug barrel until it is tight. And because it’s so very hard-wearing and resistant to oxidisation, rhodium can cope with the extra load exerted by our locking design – which ensures a perfect, maintenance-free connection.

Aircore™ Cordage

Aircore technology

Loudspeaker cables with large cross-sectional areas are prone to skin effect, where high-frequency analogue music signals are forced to the outside of the conductor, and proximity effect that disrupts current distribution. QED’s innovative Aircore technology combines hollow tubular conductors – to minimise the skin effect – with polyester insulation and a special spiral construction to reduce the proximity effect.This highly effective combination evens out current density and significantly improves the cable’s uniformity throughout the audio band.

6.2 mm2 ultra-low resistance conductors

Boasting a large cross-sectional area, the ultra-low resistance, silver-plated, oxygen-free copper conductors effectively bring the amplifier electrically much closer to the loudspeakers, enabling it to exercise better control over them, so the fidelity of the original music signal can be more accurately maintained.

Cryogenic treatment

Cryogenic treatment improves the microstructure of the copper core by eliminating crystalline dislocations. Numerous brass musical instruments at all points of the frequency range have been found to produce a better, more natural tone after deep cryogenic treatment.

QED Supremus Zr is available in July in pre-terminated options from QED retailers priced:

QED Supremus Zr 2.0 m           £1,399 / € 1,749 / $2,100

QED Supremus Zr 2.5 m           £1,599 / € 1,999 / $2,400

QED Supremus Zr 3.0 m           £1,799 / € 2,249 / $2,700

QED Supremus Zr 4.0 m           £2,199 / € 2,749 / $3,300

QED Supremus Zr 5.0 m           £2,599 / € 3,249 / $3,900

Learn more at (UK) and (US)

Technical specification

Cross-sectional area: 6.20 mm2

Wire gauge: 10 AWG

Outside diameter: 17 mm

Loop resistance: 0.005 Ω/m

Parallel capacitance: 48 pF/m

Loop inductance: 0.49 μH/m

Dissipation factor: 0.009

Technology: QED Aircore™; cryogenically treated; QED Airloc™

Conductors: 32 solid core, silver-plated, 99.999% oxygen-free, polyester coated copper

Dielectric: Foamed polyethylene, LDPE, and air

Plugs: Rhodium-plated, locking Airloc plugs with zirconia barrels

To find out more about the QED Supremus Zr loudspeaker cable and discover other QED products please visit (UK) and (US)



QED celebrates 50 years with special edition Golden Anniversary XT speaker cable featuring X-Tube™ Plus technology

British audio specialist QED celebrates its 50th anniversary in style, with the introduction of its Golden Anniversary XT speaker cable. Representing the culmination of five decades of dedicated and extensive research, engineering and audio expertise, Golden Anniversary XT speaker cable is the ideal upgrade for any hi-fi enthusiast who wants to experience the sonic benefits of a high-end speaker cable – but at a real-world price.

Key features at a glance

  • NEW X-Tube™ Plus technology combines X-Tube™ with Aircore™ to deliver an even, consistent performance across the entire audible frequency range.
  • Ultra-pure Ohno Continuous Cast Copper and 99.999% oxygen-free copper conductor blend helps improve the signal path and signal retention.
  • Low Loss Ultra-Uniform Dielectric insulation boosts efficiency and reduces signal loss.
  • Airloc™ Forte banana plugs use a cold weld system for permanent attachment to the cable for improved contact area and reduced resistance.

50 years of innovation

QED has been designing and engineering class-leading and award-winning analogue and digital cables for five decades – and the Golden Anniversary XT is the latest demonstration of the company’s expertise.

Quality Electronic Design (QED) was formed in 1973 by forward-thinking hi-fi enthusiasts, Bob Abraham and Ian Vine. The company is now considered the original cable brand, having released QED 79 Strand, widely recognised as the world’s first “specialist” loudspeaker cable. This product demonstrated how cables could have a tangible impact on audio performance.

QED’s Genesis Report on loudspeaker cable design followed. This research established scientifically proven principles, which are as valid today as they were 28 years ago and informs all QED cable designs, including the pioneering X-Tube™ technology that enables precise and consistent signal delivery across the entire frequency range.

X-Tube™ Plus technology

QED’s innovative and proven X-Tube™ technology places a cable’s conductive material around a central hollow insulating rod – and the result is the elimination of the ‘skin effect’ that would otherwise force high-frequency analogue music signals to the outside of the conductor. And by combining X-Tube™ technology with its equally effective Aircore™ technology, QED also reduces the ‘proximity effect’ that can disrupt current distribution in a speaker cable. The result is X-Tube™ Plus: a ground-breaking cable geometry that ensures Golden Anniversary XT is a speaker cable with even, consistent performance across the entire audible frequency range. 

Ultra-Pure Ohno Continuous Cast Copper conductors

Golden Anniversary XT uses a unique hybrid blend of 99.999% oxygen-free copper (‘OFC’) and Ultra-Pure Ohno Continuous Cast Copper (‘UP-OCC’) to give the improved signal path and outstanding signal retention of ultra-pure copper conductors – but at a fraction of the price. Thanks to class-leading research and engineering, QED Golden Anniversary XT is the most affordable and attainable speaker cable to exploit the advantages of the continuous-casting process, with this hybrid theoretically improving the path for transients and high frequency detail not available using just OFC alone.

Low-Loss Ultra-Uniform Dielectric insulation

If a speaker cable is to perform to its maximum potential, it’s important that the dielectric material which insulates and protects the central conductors of the cable does so efficiently. Golden Anniversary XT uses a specially developed and formulated low-density polyethylene (‘LDPE’), which works in unison with the cable’s X-Tube Plus configuration to deliver a speaker cable that has high-efficiency and a dissipation factor that is barely measurable. 

Airloc™ Forté banana plugs

Airloc™ is a specially developed cold-weld system for permanently attaching QED Forté banana plugs to the company’s entire range of speaker cables, Golden Anniversary XT included. The most vulnerable area of the speaker cable chain is the physical interface between the cable and the speaker or amplifier to which it’s connected – without effective termination, oxidation can occur, degrading the cable’s performance. By using a cold weld crimp-type termination, Forté banana plugs offer maximum resistance to oxidation – for the lifetime of the cable – by effectively turning the cable and the plug into a single, unified object.

QED Golden Anniversary XT is available now from QED retailers priced: £27 / €35 / $40 per metre.

And in pre-terminated options (available November 2023):

QED Golden Anniversary XT 2M: £219.95 / $329.00 / €289.00

QED Golden Anniversary XT 2.5M: £249.95 / $379.00 / €319.00

QED Golden Anniversary XT 3M: £279.95 / $429.00 / €349.00

QED Golden Anniversary XT 5M: £399.95 / $599.00 / €499.00

Learn more at (UK) (US)

Download QED Golden Anniversary XT White Paper

Download QED 2023 Brochure

Technical specification

Cross-sectional area: 2.5 mm2

Wire gauge: 14 AWG

Jacket outside diameter: 11.5 mm

Loop inductance: 0.58 μH/m

Loop resistance: 14.8 mΩ/m

Capacitance: 42.0 pF/m

Dissipation factor @ 10 kHz: 0.009

Conductors: 9 x 19/0.13 mm OFC + 1 x 19/0.13 UP OPCC

Insulation: LDPE jacket with 100% coverage of golden/mylar tape wrap

Plugs and spades: QED Airloc™ Forte banana plugs

To find out more about the QED Golden Anniversary XT loudspeaker cable and discover other QED products please visit (UK) and (US)