QED’s innovative proprietary X-Tube™ technology means the XT40i exhibits less distortion at high frequencies than standard speaker cables, improving overall performance through a level of timing and imaging usually found on much more expensive cables. 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. QED research has shown that low capacitance cables are generally preferred in listening tests over high capacitance counterparts and this is usually because low-loss dielectrics have been utilised. The use of LDPE and careful control of conductor spacing results in a cable with a very low capacitance per meter and a dissipation factor (loss tangent) of 0.0001 at 10 kHz. What is the result of all these techniques?

QED research has shown that low capacitance cables are generally preferred in listening tests over high capacitance counterparts and this is usually because low-loss dielectrics have been utilised. The use of LDPE and careful control of conductor spacing results in a cable with a very low capacitance per meter and a dissipation factor (loss tangent) of 0.0001 at 10 kHz. QED, established in 1973, is feeling confident these days. They claim that by using “‘top down’ design-principles,” they’ve put into their low-priced XT25 speaker cable everything they’ve learned in nearly half a century of cable design. On the flip side, If you own a high-end set-up, we'd suggest looking at price-comparable cables to get the most performance out of your system. Please note that our couriers will try to deliver as arranged but we will not be held responsible for any costs incurred because of non-delivery or factors introduced by third-parties. This service is based upon best endeavour and is not guaranteed.Using 99.999% oxygen-free copper cable, there's very low resistance, which makes it easier for your amplifier to drive your speaker as well as delivering a purer sound. It also makes the cable suitable for longer cable runs, with far less quality loss over longer lengths. 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 mm 2cross-sectional area not all of that area is available for an analogue music signal to use. In my Stereo system I can move some Spk cabinets a mm or two and make a big difference to what I hear - factor in that concept to planning/positioning a 7.1/5.1 Spk array and the difference even the most exotic pre filtered Spk cable could make is simply not worth worrying about.

Please note: TV and larger floorstanding speaker deliveries are not available to Northern Ireland, Republic of Ireland, Isle of Man, Isle of Wight, Scottish Islands, and Channel Islands. Regarding QED speaker cable and the like, a while ago I was given a pair of fairly expensive QED speaker leads, including airloc plugs on the end. My mate had moved and needed longer. In return I gave him my longer length "normal" speaker cable with cheap bananas, think the cable was Gale something or other. Try as we might we couldn't tell the difference. My mate was going to shell out again on more QED and Airlocs. He ended up keeping my Gale. It speaks about an improved sense of timing as well, and there is a definite eye for accuracy alongside attention to detail about the way our system performs with these cables plugged in. Nothing is allowed to slip, with notes and percussion hit with precision and intention. It isn’t as though previous efforts have been altogether imprecise, but there is an unerring confidence about the way our speakers play here. This kind of transparency is difficult for rivals to match.” ‘What Hi-Fi? magazine’. 5-star review.

Low-Loss Dielectric

An alternative to optical, our premium digital coaxial cables use a specially designed cable cordage and unique plug design to achieve the precise signal characteristics required for high resolution and multi-channel audio. USB A-B The basic tenant is that cable cannot "improve" the sound, but poor cable could make it sound worse.

These reports set out the “top down” design-principles that have resulted most recently in the development of QED XT25 loudspeaker cable – the new class leading standard in budget to mid-range speaker cables. We know QED for sensational levels of clarity and detail, and, even at this lower price, it doesn’t disappoint. This kind of transparency is difficult for rivals to match." (Read More) If you don’t want to meet the cost of the former, this is a cable offering the same family sound for a tighter budget, and it won’t leave you longing for the upgrade.Chord’s development work with high-end ranges such as ChordMusic and Sarum T showed significant improvements could be made to the Teflon dielectric material used. While the subsequent high-end solution of Taylon proved too expensive to use in products such as the RumourX, a more reasonably priced alternative XLPE (Cross-linked Polyethylene) was found instead in the 2018 model. Chord has introduced a new multi-metal alloy for the pug plating in the 2022 model (changed from previous silver), which claims to tarnish less over time and offers better connection quality. But it does offer us more of a musical whole. It is a lot to do with dynamic expression, those leading notes that turn accurate timing into a traceable rhythm, and which help portray a more lyrical, human bent to the music. It’s also a little to do with organisation, and how each instrument is tethered to and interacts with one another –no doubt also aided by a little less space to play in. We know QED for sensational levels of clarity and detail, and, even at this lower price, it doesn’t disappoint. This kind of transparency is difficult for rivals to match." View Full Description