QED XT25 Speaker Cable Sold With Terminations

QED XT25 Speaker Cable

What Hi-Fi Award Winning Cable

X-Tube™ technology first came to prominence in 2005 with the launch of the world renowned Silver Anniversary XT, the most highly awarded mid-range cable in the world, winning the What Hi-Fi Product of the Year three years in a row. These design principles also grace the multiple award winning XT40 speaker cable and XT25.

As frequency increases, electrons flow more and more towards the periphery of a conductor so that if the frequency is high enough only a very thin layer (or skin) on the outside of the conductor is used. This “skin depth” varies for different materials at a fixed frequency and in copper it means that if a conductor has larger than 0.66 mm2 cross-sectional area not all of that area is available for an analogue music signal to use.

In SAXT the “skin effect” problem was effectively eliminated by the use of X-Tube™ Technology which works by placing all of the conducting material around a central hollow insulating rod.

However, for a.c. signals, changing magnetic fields generated by the flow of current set up eddy currents in nearby conductors which force current to flow only in areas furthest away from conductors carrying current in the same direction and vice versa.

This “proximity effect” has a detrimental influence on current distribution in a speaker cable even if it utilises X-Tube™ Technology. With XT25 we tackle the proximity effect and the skin effect by combining our existing Aircore™ and X-Tube™ Technologies into a new X-Tube™ variation.

By forming the conductors into a tube-like shape with a hollow centre, current densities at higher frequencies are maintained because the electric field which contributes towards the skin effect acts towards the centre of the conductor from where the conductive material has been removed.

At the same time instead of using a braided structure a ring of conductors is formed into separate bundles with only a loose electrical association which are then twisted into a 90 mm lay so that no single conductor bundle remains on the inside or outside of the cable (and therefore prey to the proximity effect) for long enough for it to become an audible problem.

This geometry promotes a more consistent signal distribution making for a more accurate musical reproduction.

Low DC Resistance

At QED we recognise that low d.c. resistance of the loudspeaker cable is of paramount importance for high-fidelity signal transfer.

This is because the speaker presents a frequency dependent load to the amplifier of which the cable forms a variable proportion. If resistance is allowed to be too large then audible changes to the frequency response characteristics of the loudspeaker will be introduced which cannot be corrected for by the amplifier’s negative feedback loop.

In order to provide a marked improvement over similarly priced cables in both our own and our competitors’ ranges without increasing the overall size and flexibility of the cable substantially, the cross-sectional area (CSA) of XT25 has been enlarged to 2.5mm2 of 99.999% oxygen-free copper.

This instantly gives the new cable a low d.c. resistance and therefore a more accurate musical delivery.

• Cross-sectional area 2.5 mm2

• Wire gauge 14 AWG
• Jacket outside diameter 3.96 mm
• Loop inductance 0.52 μH/m
• Loop resistance 13.4 mΩ/m
• Capacitance 35.0 pF/m
• Dissipation factor @ 10 kHz 0.0001
• Conductors 10 x 19/0.13 mm
• Insulation LDPE jacket with 100% coverage of Aluminium Mylar tape wrap
• Plugs and spades QED Airloc™ Forte banana plugs