@tvad You have made a very good and important point that you could not discern any audible effect between several regarded power conditioners. This is in turn related to correlation between EM reduction and sound improvements.
@tonywinga I forgot to look up Furman. anyway I have looked up it's specs and they are as below.
Prestige Series P-2400 AR Power Conditioner : Filteration performance
10 10dB @ 10KHz, 40dB @ 100KHz, 50dB @ 500KHz. No mention of mode or load.
Prestige Series P-2400 IT Power Conditioner : Filteration performance
For Differential mode 10 10dB @ 10KHz, 40dB @ 100KHz, 50dB @ 500KHz
For Common mode 80dB @ 20KHz, 40dB @ 20KHz to 1 MHz No mention of load for both modes.
These specs are in line with other Audiophile grade power conditioners, nothing very different.
The reason why I don't really want to correlate SQ with EMI reduction is because of multiple factors which are as below.
1. EMI/Filteration Performance :- This is obvious factor which doesn't need any explanation.
2. EMI/RFI on power line :- Now we don't really measure how much polluted our li nes are before we even use an power conditioning. So if a line is very clean then even if best power conditioner is used it will not really have any impact on SQ.
3. Power Design of the component :- Some companies recommend plugging directly into the wall outlet. In those case & other cases here power stage is very well designed and takes care of dirty power is naturally going to sound same as with any power conditioner.
4. Personal bias and hearing ability :- Everyone has differnt hearing ability and not everyone can distinguish the changes which are subtle. Besides bias is very true and it can change one's perception to a large amount the way he percieves changes in SQ.
So if you consider all this you will understand why it's not a great idea to find correlation between SQ and EMI reduction.
While all said, I am not going to challange your experience as that what you have heard/experienced.
I think vk_onfilter has also described the impact of EMI filtering in line with my view in one of his earlier post
Audio_phool