Earthing speaker drivers.

[Reid Malenfant]

<snip> If you find the need to switch off halogen and fluorescent lamps (these presumably are plugged into wall sockets), this would suggest to me that your Isotek Substation is not doing a very good job.

The Isotek is simply a filter & while it may only be dealing with mains frequencies it will actually have to have a much higher passband to allow for the rapid current pulses demanded by modern amplifiers. No filter is perfect & one that has less garbage to deal with will obviously have a cleaner output than if it has a lot to contend with. Just my take on things, but in this case it really does come down to 'garbage in, garbage out'

<snip> its not a fussy system, it sounds fantastic all the time, but if im listening critically the benefits are easy to hear.

I find that makes a lot of sense Kill the interference at source, rather than try to deal with it.