QED Reference XT25 - Unterminated
- Brand: QED
- Product Code: Reference XT25 - Unterminated
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.
X-Tube™ technology first came to prominence in 2005 with the launch of the world renowned Silver Anniversary XT, the most highly regarded 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.
At low frequencies both X-TubeTM and conventional stranded/solid core speaker cables convey signals in a linear way. However, at high frequencies, X-TubeTM retains a near-linear signal transfer, whereas the conventional cables fail to conduct uniformly across the entire conductor area.
In standard speaker cables at high frequencies current flow is highest at the periphery with rapidly deteriorating current density towards the centre of the conductor.
The effect of this is to reduce the actual cross sectional area of the cable at 15kHz to less than 75% of that at low frequencies. This results in higher distortion and compromises the performance of the cable.
X-TubeTM with polycore technology exhibits much lower self-inductance and is therefore less affected by this problem. The polycore technology reduces loop inductance to levels only achievable using more costly and difficult to terminate cables.
The result is more high frequency detail, less distortion and greater performance.
JACKET OUTSIDE DIAMETER
@ 10 kHz 0.0001
10 x 19/0.13 mm
LDPE jacket with 100% coverage of Aluminium Mylar tape wrap
PLUGS AND SPADES
QED Airloc™ Forte banana plugs