50m reel of QED XT25 cable
What are the features which make this cable so special?
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.
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.
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.
It is not generally appreciated that the electrical signals moving at or near the speed of light in a wire do so via the medium of electromagnetic (EM) waveforms which exist within the dielectric which surrounds the conductors as well as within the conductors themselves. The movement of electrons along the conductor merely facilitates generation of the EM waveform as their “drift velocity” is only a few centimetres per second. 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. Dielectric losses are directly proportional to the “permittivity” of the material used and as this a measure of each material relative to that in a vacuum it should be as close to unity as possible. Like its predecessors, XT25 uses a specially formulated low-density polyethylene (LDPE) dielectric which at 1.69 has the lowest relative permittivity practically available.
What is the result of all these techniques?
The graph below shows how the dc resistance of XT25 remains effectively unchanged across the entire audible frequency band when compared to a conventional cable of the same cross-sectional area. Combined with the sonic advantages of a low loss dielectric the improvements in current distribution place the new cable in a class well above cables with a less sophisticated geometry.
So, unless you invest in XT25 with QED X-Tube™ technology you can be losing a lot of the performance of your expensive loudspeakers.
Make sure you make the most of your new purchase by asking your dealer to fit QED AirLoc™ Forté plugs which are designed to keep XT25 sounding as good as new for life
JACKET OUTSIDE DIAMETER
@ 10 kHz 0.0001
10 x 19/0.13 mm
LDPE jacket with 100% coverage of Aluminium Mylar tape wrap
Order and Delivery Information
Thank you for considering Yorkshire AV for your next investment in your AV setup.
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Selecting "Next Day" delivery does not mean you'll receive your item the next day in some cases. It's the next day from when the item(s) are in stock with us. If there is an urgent need then please contact a member of staff via the Live Chat or telephone (01757 826111) to check on live stock levels.
We do ask for some patience during lockdown - we're working remotely from home and travel to the warehouse each day to fulfil orders. If item's aren't in stock - we can usually get them within a couple of days.
We're a small business that's been impacted massively due to COVID-19 and have such had a significant reduction in orders. We're focussing on core products and services with less frequent products being ordered "on demand".
When will orders be dispatched?
- Orders placed Monday - Thursday before 2pm and are in stock will be dispatched the same day for next day delivery. This relates to product that state 'In Stock for immediate dispatch' on the product page.
- Orders placed on after 2pm on Thursday or on Friday will be dispatched for delivery on Monday unless Saturday delivery is selected.
- Orders placed over a weekend and are in stock will be dispatched on Monday.
Orders for items not in stock
Given the vast amount of variations of each product (e.g. AudioQuest cables) or Pro-Ject Audio Turntables - we keep the most common options in stock (i.e. gloss black finish, or 1.5m RCA cables) whereas longer cables or cables with terminations that are less frequently ordered will be ordered as required.
Generally speaking - we receive orders within 2-3 days for UK suppliers and 3-4 days for European suppliers (i.e. AudioQuest, DALI).
We want you to be 100% satisfied which is why we'll give you an email/call if item(s) aren't in stock and give you the option of changing the order, cancelling or if you're happy to wait a few days, we'll get it out as soon as possible.
If an item states 'Available to order. Usually dispatched within 48 hours' - this means the item is not in stock but we are able to order in. Lead times average 2 days but in some circumstances, delivery times may be longer and is outside of our control. Please contact us to get an estimate on delivery times if orders are urgent.
Who do you use for delivery?
Our primary delivery agent is DHL. Where orders are shipped directly from Yorkshire AV, we always use DHL who offer a fabulous service at competitive rates.
If we drop ship (i.e. direct from the supplier) then the delivery agent is out of our control. It is generally DPD or UPS however - we rarely see other carriers used.
As always - we welcome a conversation about your requirements and will always explore all options to connect you with the right solution.
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