Review on Metra AX-AGL610 Axxess Ground Loop Isolator for Enhanced SEO by Samiran Pusarla

I bought two of these components and connected them to my car radio. I have many years of experience in car audio installation. I already had HF-dampening ferrite toroids in all associated cables. I had very solid bases and a large straight wire to the positive battery post. I tried to isolate the power cables from the audio cables as much as possible. Before these isolators were added, there was a slight engine hum in the speakers that was much more noticeable at low volumes or when no music was playing. I added these ground loop isolators thinking it would be the solution but without much success. I can't identify any other source of noise, so they're either not working or I'm missing something.