I purchased two of these filters (one for front, one for rear) after getting an annoying squeal that fluctuated with acceleration input through my Kenwood receiver. I noticed this was primarily coming out of my left-rear speaker. After installing these filters, the squeal has been reduced to barely noticeable levels (albeit not entirely eliminated). Installation was a breeze, as I simply unplugged my RCA cables from the factory amp into the radio and plugged the filter to run in series between the radio and the cables (it is even simpler than it sounds). For my installation, I didn't need to hook up the brown ground wires, it just worsened things if they were connected. Overall, good product and I recommend them if you are experiencing similar issues.