I am doing a shielding experiment, where I wish to shield against frequencies of 0.5 - 100 Hz. For this purpose I have chosen Mumetal. Unfortunately Mumetals initial permeability has a dependency on frequency, meaning after around 500-600 Hz the initial permeability will plummet towards 1.
My question is this: what if the mumetal is irradiated simultaneously with a high frequency (above 600 Hz) signal, and an ELF (0.5-100 Hz) signal, will the ELF signal be able to penetrate the mumetal (Assuming that it cannot on its own), or will the combination of the two create a new unique signal that does not classify as being between 0.5-100 Hz?