10 Amp CB Audio Noise Filter Suppressor Stereo Car Audio Part

This things work wonders, BUT you can’t install just one, the head unit (radio) in your car has “2” power sources, constant 12v and key (ignition) 12v you have to install one of these noice suppressor on each 12v source to eliminate 100% of the engine whine, I had it bad, my amp gain was set way low and I could not get enough volume out of my speakers, I installed “2” of these on my head unit power and ignition and my sound system sounds great, my amp gains are set up nice and the sounds is crisp with zero engine noice, I even pause the music and rev the engine and nothing but silence.