RECOIL GLIRCA 2-Channel RCA Stereo Ground Loop Isolator Designed for Audio Signals Eliminate Noise

I installed a new 5-channel amp and sub in my Jeep. After install, there was very noticeable alternator whine. I would disconnect the RCA connections at the amp, and it would go away. After checking the grounds and trying other things, I figured why not try these. I bought two for the front and rear RCA pair, plugged them in, and NO MORE NOISE! To be honest, I didn't expect them to work and was prepared to just send them back. Couldn't be happier...cheap, easy, and does what they're intended to do!

Hooked this up to filter noise coming from my speakers. It toned the whine down to about half as loud, but you can definitely still hear it.

Works great after it was grounded. Will stop working after a while if it isn’t grounded. Don’t use the same ground as the rest of the audio.

I had a lot of alternator whine and other noise coming through my speakers after installing an amp that did not change regardless of what volume I had my headunit at. I thought that it was a ground loop issue so I bought an isolator that had female RCAs for both in and out, and this isolator that could simply plug in-line with my existing RCA cable. I wanted two different styles of isolators so I could figure out if one worked better than the other. Since I had two sets of RCAs to isolate, having 2 different isolators seemed like a reasonable approach. I also liked how this one had the ground wires exposed just in case I needed to use them. Well, in my case, neither ground loop isolator worked for my issue (because it wasn't actually a ground loop problem, not the fault of this product). Nevertheless, this isolator is advertised with "Close to perfect response of +/- .03 db from 2 to 20,000Hz" which is absolutely false. With this isolator plugged into my speaker amp RCAs, the treble gets noticeably brighter and louder than the mids, bass, and sub-bass. That is undeniably not "+/- .03 db", more like +/- 3.0 db. Now, I also had this plugged into my subwoofer amp RCAs and did not immediately notice any difference so perhaps it would be okay for that use case. I did not bother to measure the frequency response with this isolator plugged in and unplugged so I can't say for certain what frequencies are affected and to what extent. I only know that the treble response is altered and that is not what I was looking for. The other ground loop isolator that I purchased did not alter the audio signal in any way that I could tell by ear. As for the root cause of my noise, it turned out it was the RCA outputs on the headunit. I took this ground loop isolator apart, removed the two capacitors that were in there, and bypassed the isolation transformers. That let me easily use the two brown ground wires coming out to ground the headunit RCA outputs to the metal of the headunit itself (grounding it anywhere else led to some noise still making it through to the speakers). Noise is gone and I didn't have to make any permanent modifications to my headunit.

It was kind of confusing to figure out, I bought this for my turntable, Its a newer turntable I was trying to hook up to my 92 technics stereo system. my turntable doesnt have a ground port and I was hoping this would help the hum. It didnt work for my intended use. Ended up having to purchase ground wire and MacGyver my own solution.

I used this in conjunction with an HDMI video adapter to add video capability to my JVC auto stereo while using an iPhone as the video source. Without this device, I was getting a lot of extra noise with the audio, even with the engine off. The only drawback is that when I play video, the sound is really low. You can turn up the volume really high to hear it, but you have to remember to lower the volume when you switch to another source. I'm not running an amplifier, just the stock speakers, so I'm sure some further upgrades to the stereo would help with the volume. I am very satisfied with this item. I did not have to use the extra ground wires, and the device comes with instructions in the package regarding the use, if needed, of them.

I've had the same set up for at least 10 years; HD TV, Xfinity cable box, sound bar, and sub-woofer without ever having a humming noise and then with no change to anything, about 2 months ago the sub-woofer started emitting a humming noise. Tried the sub-woofer electrical plug fixes recommended on a GOOGLE search and they all worked for about one day and the humming noise returned. Out of frustration I bought one of these as a connector between the regular RCA jacks from the sub-woofer. The humming noise has been completely gone now for about a week so I'm guessing this thing really works and the humming noise will not return. I still have no idea what caused the humming noise kinda out of the blue but this thing is working. It was the least expensive one offered on Amazon.

Feedback got louder after removing old one and installing this one. Randomly drops all sound for a few minutes then my highs will come back, thought it was the amp going into protection mode but no, just lost signal and does it constantly, not happy with it.

Works well, sounds good, and the u it is bi-directional. Simple plug and play and it took care of my ground loop. No noticeable decline in volume or quality

The device works, but it also reduces power, it was not a good purchase. Eliminou o ruído do subwoofer, mas retirou as frequências baixas do subwoofer, retirou 70% do grave, não recomendo para uso em subwoofer.

Item was installed to reduce the noise created by the alternator, made no difference

Removed engine noise but also removed all low end frequencies and did not touch hissing noise.

This product eliminated the subwoofer hum that was evident in my subwoofer. Product worked as described.