Bass Rockers Ground Loop Noise Isolator Filter for Car Audio Home Stereo RV System with 3.5mm AUX Audio Cable-Fully Eliminate Buzzing Noise

It works! Sound quality is excellent. Even with audio jacked up high, no engine whine. I use this product in my 2010 Subaru Outback, and in my 2011 Mini Cooper convertible. Like night and day.

Had an awful buzzing sound when I added an active speaker to my PA daisy chain. After some reading I discovered that is **likely** due to the fact they're not plugged into the same source. I added this onto the speaker which is fed with a 40' 3.5 mm cord and the buzzing cut down significantly. There is still a little, and I imagine if the volume were to be cranked on my speaker it would loud, but at a "normal" volume it's not noticeable during the record playing and barely noticeable when the music has stopped. For an inexpensive product, it fit the bill for my little DIY piece-meal soundsystem.

had a lot of line noise on my headphones before using this plug and it's gone

I have a Christmas light show tuned to a radio station. I needed a filter for the audio and bought this one. I could not hear a change with this plugged in. I tried extra aux cords as well.