Products & Accessories

Records & CDs

Special Offers

Repairs

Services

Bespoke Modifications

About Us

Contact Us

Ordering

Events Diary

Showcase

Features

Audio Myths: Silver Wire sounds bright

Above: Silver wire in loose cotton insulation

Audio Myths: Silver Wire sounds ‘bright’

This is one of those persistent myths that is frustrating yet ultimately has a basis in truth.

Good quality pure silver wire in its raw state sounds wonderfully transparent and lucid. Compared to copper it simply appears to have less character - a good way to describe the sound off copper is that it is a little heavy handed, thickening the tonality of instruments and lacking the lightness of touch of silver. Silver does not accentuate the treble but does appear to allow greater appreciation of recorded room acoustics and ambience.

So where does the bright reputation of silver come from?

Firstly many so called silver cables are actually silver plated copper and in my experience these invariably do have a brightening effect on the sound and commonly a lack of continuity between the highest registers and the midband. It is this effect that is often blamed on the skin effect - where high frequencies travel on the outside of the cable (in this case the silver) and the low frequencies closer to the centre (the copper). However whilst this does have a sound basis in physics the effect is normally considered to happen at frequencies way beyond the audio spectrum (above 1 Mhz). Whatever the actual cause, my listening tests show that I prefer not to use silver plated wire at audio frequencies wherever possible.

There are many different types of silver wire, with varying properties including levels of impurities. These elements make a substantial difference to the sound. I only use very pure 99.99% wire in my own wiring but that specification alone is not the only important one, the annealing process (heat treatment leading to softening of the wire with benefits including grain growth) is also critical.  

Another aspect was one that I stumbled upon quite by chance. The way the wire is treated during cable construction is remarkably important - allowing the cable to become stretched during twisting/plaiting for example changes the sound. What’s equally fascinating is that the burn in effect that is often heard with cables becomes much more of an issue if the cable is overly stressed and stretched. Quite simply, the less the wire is worked the better it sounds, so the key is to be very gentle with it during cable manufacture. I should add that normal handling of wires by an end user is not in my experience sufficient to cause a problem.

When making speaker cables and interconnects the type of construction, number and diameter of strands are also terribly important, but this is an area I will leave open to your own experimentation to avoid giving away all of my trade secrets.

I’ve left possibly the most important aspect to last. The insulator around the wire! If you look at the properties of various insulators in a text book you will see that apart from a vacuum (which is a little impractical for cable manufacture), air is the best insulator. In terms of man made materials PTFE (Teflon) is the next best. However this is where I will differ from many (but not all cable manufacturers). Silver wire insulated with PTFE has a brighter and more synthetic sound compared to an air insulator and spoils the tonality of instruments.

Interestingly some firms (most notably Atlas Cables) are successfully using microporous PTFE, which has small air filled voids in it, not entirely dissimilar in theory from using loose fitting Teflon around silver wire, which is exactly what I use for high voltage applications as the wire is almost completely in air, with just one edge touching the plastic. This effect isn’t exclusive to PTFE, all plastics exhibit the same problems to my ear which is why I prefer to use natural materials as insulators (such as cotton) for audio level connections - the difference is quite remarkable and it simply appears to ‘get out of the way’ more effectively than most other types of cable construction.

Some research in France has been carried out which may go some way to describing this phenomenon, this theory is called ‘Micro Discharge Interface’. This government funded research took place in 1997 and claims there is intermodulation distortion of the audio signal caused by high level ultrasound that occurs during transmission of alternating current signals. It claims the insulator and wire material both appear critical to reduce this effect to a minimum.

I feel that the microphonics of a cable are also remarkably critical and often over looked, but this is something I will perhaps leave for another time.

Back to Features

Home > Features > Audio Myths: Silver wire sounds bright