I have a new residential customer that has these installed on there NEC SV 8100 phone system

I don't think they where working very well prior to a lightning hit that needless to say caused some major issues

so the customer ordered new ones

they sound like crap its not clear I talked to Valcom and they seem to think it had to do with power

They asked me what I was using for a power supply and I told them the one that came with the unit he suggested a different power supply one that is filtered it comes with a VP324-D and the suggested a VP624


Just wondering if anyone had any suggestions