In the urban power grid, there are significant low and high frequency electrical interfering fields flowing from the power lines into the devices and then distributing to all Hi-Fi devices of the audio system via the cable connections.
In addition, directly within the domestic power grid there are critical electrical consumers (switching power supplies, computers, energy-saving lamps, refrigerators, heating systems, cooktops, routers, AV systems, etc.), which feed massive low and high-frequency interfering fields into the power grid distributing to all HiFi devices via the cables.
Common solution approaches and their limitations:
A common approach in the power sector is the use of line filters, conditioners and grid generators, which are operated in front of the Hi-Fi equipment, so that interfering fields should not reach the devices via the power grid.
However, current pulse peaks are often over 20 times the power consumption of the devices, so at a total power consumption of the audio system of only 500 W, the current pulse peaks can be over 10,000 W. Even generously designed with several 1000W line filters or grid generators therefore limit the dynamic flow of music in high-quality audio systems. Even with parallel current filters and not just in the signal path lying in-line power filters, it comes to transmission delay effects, since required components such as capacitors, diodes, etc. absorb energy and release it again with a time delay.
In addition, line filters often do not allow the inner interferences caused by the hi-fi devices themselves to escape to the outside due to their blocking function.
The use of common power-cleansing measures is always fraught with compromises that block the way to a higher level.