Why power cable effect overall syste sound?

I found recently that my power cords from one company was changing my sound and tone and affecting its overall dynamic range. I now use Running Springs HZ cords and one of there claims is to not be used as so called tone control. My system was fine with stock cords in places but much better dynamics and resolution with the new HZ cords in. Sometimes you can insert a cord or cable be it a power, ic, or sc, and get a sound change you find inviting only to later wonder if your timing and detail is lacking or just not right. With the HZ cord it didn't change the tone from stock cords at all, it expanded dynamics and detail while allowing the frequency response and tone to be left alone.

I have learned some cannot taste the difference when we change a product while others can (blind testing)

BINGO, enough said.
Well, actually I must add, to my experiments/ experience with cables & cords, I'm fortunate to hear and "see" differences between each 1 of them (the higher in price, the more obvious) almost equivilent (or more) when switching with diff components. I actually enjoy sitting down with the non-believers to demonstrate & to acknowledge them the characters differences in cables & cords. Their becoming as a cable believers is my cup of tea, mission acomplished.

I think one of the main points missing here is not that cords and cables make no difference, but that people are preoccupied with them and forget room treatment which I find to be far more important, as I think speaker cables are more important, and interconnects being of high importance. A line conditioner is also important especially for digital and SS equipment. And not to forget, the position of the speakers in the room, the listening position, and a host of other things are so important, cable fixes, all the way up and down the chain are used instead of getting the speakers right in the room. Cables should be used to fine tune the system. Using a measuring system, like a mic to evaluate the sound in the room at 1M, and at the listening position will reveal a lot of the room and characteristics. Don't rely of your Ratshack meter, it is rolled below 50Hz, and above 10K. So, don't go and buy another power cord if you are rolled at 10Khz, it is your meter.
If your room and system is right, and all is right and you hear improvements in your power cords, keep them, use them, and stick by what your hear. Your ears are your experience, so be truthful to that.
Personally, I have heard many power cords in different systems, and in some systems there was a difference, others there was not one of significance. The cords evaluated were the best from Shunyata, Cardas, Audioquest, and many others. Each system will have different RF issues, and others. Trust your ears, not the money spent....
Jallen

Thank you Samuel!!

Samuel,
Thank you a lot for answer. It was very well explained. The high frequency backward noise from digital source is well known issue. That's why for digital source is highly desirable to use shielded AC cord or some cable manufactures insert HF filter prior IEC socket to eliminate antenna effect. But I amaze to hear the impact on pure analog system without any clock source.