I had a similar problem with my Meridian 557 because I switched to XLR cable and left the RCA plugs blank.
After makeing up shorting plugs for the the RCA jacks
the noise went away. I still hear the slightest hiss but I would assume this is because the speakers are accepting
the signal from the power amp.
After makeing up shorting plugs for the the RCA jacks
the noise went away. I still hear the slightest hiss but I would assume this is because the speakers are accepting
the signal from the power amp.