I recently picked up a $30 EMF meter to see if it could tell me more about the invisible fields that are around my components. We all knew this – but I’ve since found varying levels/distances of magnetic and electric fields emanating from different components and cables. There are also “hot spots” where it looks like the EM fields converged to create a much stronger field.
Given the article I shared earlier, I’m certain that physical sound vibrations, the audible frequencies traveling through the signal cables, and ground/noise current loops are causing these fields to interact and induce currents in each other.
I hypothesize that these EM induced currents will enhance certain frequencies and others will cancel in time with the signal, creating micro peaks and nulls in random ways across the audible frequency spectrum – not unlike how a room creates peaks and nulls from wave reflections. EM fields will undoubtedly be in or out of phase with each other depending on component and cable positioning – and distance is the only characteristic that can help reduce these EM induced currents.
I’m thinking through what a suitable experiment setup could look like to test this hypothesis, but in the meantime – some logical next steps would look like this:
- Use an EM meter to measure the peak EM field of your device at volume – higher currents produce stronger fields, so strength of field will go up as you move from signal wires, to speaker wires, to power cables. The fields are three-dimensional, so they may be stronger/weaker depending on the underlying cable structure and will always weaken as you move further away – the distance to record is when the meter measures 0.
- This is the distance you want to separate your cables and components from each other. Stacking components is just not a good idea – even on a shelf – especially if it has a massive transformer in it.
- I don’t know what to do about power strips, conditioners, regenerators just yet, but keeping power cables parallel and never crossed is likely a good thing. As they all say, if you must cross, do it at 90 degrees as fields are perpendicular to the direction of current travel – and minimize curves within the EM field distance.
- Anything with a transformer needs distance (those of you fiddling with phono preamps knew this already) – and in some cases, a lot of distance. There isn’t any known true shield to magnetic fields – though electrified meshes and solid copper plates will help redirect magnetic field lines away from anything on the other side – just keep in mind this potentially redirects the field line straight to another component or unto itself in the case of solid conducting pipes.
- Reduce vibrations to an absolute minimum. Vibrations cause the magnetic waves to vibrate (just as moving a magnet moves its field) – this is immediate, and that slight shift back and forth will induce a current in all nearby conductors.
Separating high EM fields from low EM fields would yield the highest impact since low level signals (phono cartridge wires, for instance) are much more susceptible to minor current fluctuations. These fields, coupled with movement (i.e. vibrations) induce currents, so vibration isolation is just as important – all phones have gyroscopes sensitive enough to detect minor vibrations and can be exposed via a vibration measurement app; these will be tough to use on cables, but assume a cable resting on the floor will vibrate – so long as that cable’s EM field is not contacting another EM field, it’s OK to rest on the floor.
And that’s why I posit cable elevators can be helpful in creating the separation and enabling vibration isolation.
Thoughts?