I've just recorded a background noise test between a Maplins Premium RCA and a Van Damme Silver Lo-Cap 55.
To highlight the EMF I've set the monitor gain to +6 db and the high frequency to +1 db. Normally I run the monitor at -6 db gain, and a high frequency to -1 db. So I'm +12 gain from what I normally use.
You need to compare the Maplins audible noise background at 25 seconds to the time before and after that is the Van Damme, it's clear evidence the Van Damme cable reduces EMF over the Maplins Premium cable.
And finally I set the monitor settings back to -6 db gain and -1 HF db where EMF is not audible and I also play some music over the speaker. I do this to prove this is how I normally play music from the speaker. Also I'm doing this with one hand, the thuds you can hear are the RCA cables dropping onto my desk as I pull them out to switch them.