The ground isolator will not help if you are not getting sound from the audio, also I am not a big fan of them anyway with high end amplification, actually makes things sound worse when I tried one. For me it was easier to use a cheater plug on my 350's and now things are dead quiet.

M80s VP180 4xM22ow 4xM3ic EP600 2xEP350
AnthemAVM60 Outlaw7700 EmoA500 Epson5040UB FluanceRT85