QED Reference XT40i Speaker Cables
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QED Reference XT40i Speaker Cables
Key Features
- Low-Loss Air Gap Dielectric
- X-Tube™ Technology
- 99.999% Oxygen-Free Copper
- Award winning QED cable heritage guaranteed
- Lifetime Warranty
The Next Evolution in Audio Excellence
As QED Cable Brand rapidly closing in on its fifth decades at the forefront of speaker cable design, QED’s brand new Reference XT40i speaker cable builds on the formidable reputation of the XT40 speaker cable it replaces and offers a decisive step up in sound quality. This pure oxygen-free copper cable uses an evolution of QED’s established X-Tube technology to guarantee superb timing and stereo imaging, and adds the brand new and highly innovative Air Gap dielectric to bring unheard-of rhythmic accuracy and musicality to a cable of this modest price. Very low DC resistance adds unrivalled frequency response to XT40i’s already potent audio capability. The result is a cable that advances on the class-leading standards set by its predecessor.
So what are the features which make XT40i speaker cable so special?
X-Tube™ technology, introduced in 2005 with the award-winning Silver Anniversary XT, has since powered QED’s top-performing cables, including XT40 and XT25. As AC frequencies rise, the “skin effect” forces current to the outer layer of a solid conductor, meaning larger copper cores aren’t fully used for music signals. XT40i solves this by using a hollow central rod that forms the conductor into a tube, equalising current density across frequencies and effectively eliminating the skin-effect issue for more accurate, consistent sound.
Low DC Resistance
The Silver Anniversary XT cable delivers superior performance for all your hi-fi and home theater needs. It was designed to replace the Silver Anniversary speaker cable, combining the features of Silver Anniversary with the added enhancement of X-Tube™ technology to combat the skin effect and deliver stunning detail. At low frequencies both X-Tube™ and conventional stranded/solid core speaker cables convey signals in a linear way. However, at high frequencies, X-Tube™ retains a near-linear signal transfer, whereas the conventional cable fails to conduct uniformly across the entire conductor area. This delivers greater fidelity across the audio spectrum which would otherwise be lost in ordinary cables.
Low-Loss Air Gap Dielectric
It is not generally appreciated that electrical signals moving at or near the speed of light in a wire, do so via the medium of electromagnetic (EM) waveforms, which must travel within the dielectric which surrounds the conductors as well as within the conductors themselves. It is therefore important to ensure that the dielectric material used to insulate and protect the central conductors of the speaker cable is of a type which ‘permits’ the establishment of EM waveforms without appreciable loss.
To make XT40i a user-friendly, easy-to-terminate cable, a soft PVC outer jacket has been used in combination with hollow PE rods which would ordinarily only give average results as far as dielectric performance goes. However, due to the advantages conferred upon it by its X-Tube™ geometry, the increased separation of the conductors results in much more of the space between them being made of air, which has the effect of reducing the dielectric constant of the insulation without even changing the materials.
In this way, using an Air Gap Dielectric both capacitance and dissipation factor have been halved when compared to the old award-winning cable, bringing audible improvements in musical timing, lower distortion and better transient performance.
Is there a measurable audible result of all these improvements?
The graph below shows how the resistance part of the impedance of XT40i speaker cable remains effectively unchanged across the entire audible frequency band when compared to an ordinary speaker cable of the same cross-sectional area. Combined with the sonic advantages of a lower-loss dielectric, these improvements place the new speaker cable in a unique position to rival its illustrious predecessor.
During development, we typically design and test at least four variants of each design to see where the extremes of each of the parameters lie. The cable that eventually becomes a product has been measured and listened to exhaustively and represents the best state-of-the-art at any given time. QED XT40i speaker cable is no exception in this regard.
Product details
Overview
- Low-Loss Air Gap Dielectric
- X-Tube™ Technology
- 99.999% Oxygen-Free Copper
- Award winning QED cable heritage guaranteed
- Lifetime Warranty
Specification
Capacitance: 35 pF/m
Cordage Outside Diameter: 6 x 14 mm
Dissipation Factor: @ 10 kHz – 0.0295
Inductance: 0.57 µH/m
Loop Resistance: 8.0 mΩ/m
Included in the Box
2 x QED Reference XT40i Speaker Cables
Explore the series
QED Reference XT40i Speaker Cables
QED Silver Anniversary XT Speaker Cables
QED Golden Anniversary XT Speaker Cable
