I had a new solar system installed with a SunSynk 12K-SG04LP3 three-phase inverter, 16 panels and two 6.4kW batteries. The system is working as expected and the installation was properly performed by an experienced company.

I have a dedictated audio/home theatre which I built about 14 yrs ago. We recently had periodic power outages and when there was no grid power connected I got quite loud buzzing from the power supplies of my powered subwoofers, amps and preamp. I had to switch off wall power before the noise stopped. In standby mode the noise persisted.

When there is grid power connected the noise is much better except for some low level but audible buzzing noise from my two JL Audio F113 subwoofer amps. The other components seem ok.

My inverter setup has a physical earth neutral bond. We tried Island mode but it did not change the buzzing. An electrical consultant has checked the installation and wiring and all seems ok. He feels that there is probably some distortion/noise/harmonics induced by the inverter. Ground loops are another possibility.

Are you able to advise how I can approach this problem? Any filters or suppressors etc that can be tried?

I would really like to try to resolve this problem.

Thanks

Jose