PAC SNI-1 Noise Isolator, 1 Count

I just finished a massive stereo upgrade in my truck that included ripping out the ENTIRE interior, installing sound deadening materials and re-wiring everything. I installed a high-end touch screen head unit, component speakers up front, coax in back, wired up for a sub (to be installed later) and included an Infinity Reference Series amp. The first time turning it on I was so thrilled with the way it sounded! I spent a few hours tweaking and adjusting the inputs and levels to get it just right. What an upgrade to the factory system!Until I turned on the engine...All of the awesomeness disappeared in a flash when I heard the loud hiss and whirring noise in the background as soon as I started the engine. I felt like all my effort was for nothing... I pulled a bunch of things apart, testing various connections and ensuring that I had good grounds everywhere, etc. After a couple of hours of swapping cables and trouble-shooting (including testing voltages across various ground points, etc) I finally gave up and decided to "punt" and install ground loop isolators. These are usually a "last resort" because they typically attenuate the signal coming from the head unit and there is a discernible loss of sound quality in higher end systems.After a bit of research I decided on these PAC units - mostly because of positive results being reported, but also because of their reasonable price (some other units I considered were $50 each).They took just a few minutes to install to the head unit and I hesitatingly turned the stereo on (without the engine) expecting to hear a dramatic loss in sound quality. I was THRILLED to find that I could not tell the difference with the typical music I listen to (reggae, jazz, classic rock). I didn't even need to tweak to EQ to maintain the natural sound I had before.This seems to be one of those rare cases where the manufacturer's marketing hype actually seems true - they totally eliminated my engine noise without creating a discernible change in sound quality.

It worked perfectly! I have an aftermarket car radio and subwoofers w/ an amp, and tweeters with their own amp also. The tweeters gave out a significant whining static sound that increased with engine RPM. After chasing down various solutions, I bought this RCA ground loop isolator, plugged it in, and VIOLA! Totally solved the issue! (Read the instructions and hook it up correctly!)

When my subwoofer rca was plugged into my dsp it would create a loud alternator whome through all my speakers but only when the sub rca’s are connected. Decided to give this lil guy a try and honestly it solved all of my problems. There is no more signal interference/whining/ hissing nothing coming from my speakers when using the SNI-1. Plugged it directly into my subwoofer amplifier rca input and the connected my rca’s. No more disturbing noise. This did not affect my bass either as some reviews said it would muffle or decrease the bass. It has done neither in my experience so far i havent noticed any loss in bass but then again i have alot so maybe the lil bass i lost isn’t noticeable. But overall if your experiencing a very loud whine/hiss or any signal interference give this a try and see if it works you. To my surprise it worked for me!

I purchased a small, 40w amplifier to drive the two rear 6x9" speakers, each in their own enclosure, in my '85 El Camino. The amp was mounted under the passenger seat, and I ran a 6' or 8' rca type phono cable from the Alpine AM/FM CD player's preamp outputs to the 40w amp, under the carpeting. The phono cable I used apparently was not very shielded- it was from my home stereo system so did not have to be. The rear amp worked fine and sounded great, until I started up the car and went for a test drive, where I was disappointed to hear squealing and popping coming for the rear speakers. The front speakers played fine like they always had. I did some more troubleshooting and determined that noise was most likely coming in via my unshielded phono cables, which I did not want to remove. I did some research and came across this noise isolator, and decided to give it a try as it was fairly inexpensive. The long and short of it was that it worked and I have a normal sounding stereo. I did have to connect the two wires to each other and then to ground. Also, the noise isolator needs to be mounted at the remote amplifier, not near the deck, which makes sense since the noise is coming through the phono cable. That being said, the rca connectors will not work without having some adapters to change the sex of the plugs/ jacks around, since they are reversed from what they need to be. That is why I did not give it 5 stars. I am guessing that most folks would have problems similar to what I did due to using poorly shielded phono (RCA) cables between the deck and the remote amp.