Maybe they are…
By Roy Gregory
In a recent BBC story, Chris Baraniuk, a highly respected science and technology journalist reported that fibre optic cables can detect adjacent noise and mechanical interference. The story reflects on the possibility of using this capability to help detect and prevent sabotage of undersea links – both optical communications cables and also power cables, that often incorporate optical fibres for data transfer functionality. The BBC might not be the paragons of objectivity they once were, but they’re definitely not Fox News, so it’s worth treating this information seriously.
https://www.bbc.com/news/articles/cn52rglxr62o
Whilst anything that stops bad-actors dredging up and destroying communications and power infrastructure can only be good news, it’s a story that has interesting implications for audio applications. Increasingly, high-quality home audio networks employ fibre optic links for long signal runs and to provide galvanic isolation from ground noise generated by network components and other equipment that’s network connected. Now, there’s a (literally) huge difference between an undersea comms cable and the single-mode fibre you ideally use in your domestic network. But if fibre optic cables are microphonic then the somewhat cavalier attitude that the audio community has developed towards their use might need modifying. Not only are long runs routed through wall and ceilings or floors going to be highly susceptible to structural vibration, but excess cable used in isolating optical bridges will need to be kept as short as possible to avoid unnecessary exposure.
While running lengthy optical cables is clearly superior to using standard Cat6 or Cat8 ethernet cables and there are very real benefits to galvanically isolating your sensitive digital electronics from the noisy domestic network, these are not sonically ‘cost free’ solutions. Are the effects of mechanical interference on optical cables audible? I don’t know, but it seems like a good idea to find out, especially as remedial action should be reasonably straightforward. Meanwhile, I can’t help chuckling to myself when I consider what the “It’s only ones and noughts” brigade are going to make of this one…
