hello, I bought a pair of monitors eris e5 a few days ago and I immediately realized that by connecting the power cables and turning them on (without input signals) you hear a slight rustle (white noise) emitted by the tweeters (of both monitors) when I close my ear .. which seems strange because without audio cables inserted at the entrance there should be no noise ... I also noticed that the amp behind overheats too much too quickly ... I hope you can help me to understand if all this is normal, thank you!