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PAC SNI-1/3.5 Noise Filter

Helps eliminate ground loop noise from your portable music player! (3.5mm plugs)

97 Reviews | 3 questions - 8 answers

Item # 127SNI135

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Our take on the PAC SNI-1/3.5 Noise Filter

Problem: You plug your portable music player into the aux input on your car's receiver, but there's an annoying whine along with the music.

Problem: You plug your portable music player into the aux input on your car's receiver, but there's an annoying whine along with the music.

Solution: PAC's SNI-1/3.5 preamp noise filter plugs in between your receiver's auxiliary input and your portable music player to help reduce noise caused by a ground loop. The filter includes a female 3.5mm input, a male 3.5mm output, and 10 inches of cable for each jack. Warranty: 30 days.

Helped reduce alternator whine, did not entirely eliminate (2001 Accord with aux adapter plugged into CD changer socket on factory radio) Definitely worth its cost.

Jack, Austin, TX

What's in the Box:

  • Noise filter with attached 10" input cable (terminated with female 3.5mm minijack) and 10" output cable (terminated with 3.5mm male minijack)

PAC SNI-1/3.5 Noise Filter Reviews

Average Customer Review(s):

(97 Reviews)
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Hands-on research

Product Research


Application: This noise filter is great for eliminating ground loop noise between an auxiliary source and radio.

Frequency Response: This noise filter has close to perfect frequency response of +/- .03 dB from 20-20kHz.

Gain: Unlike other manufactures that use 1:1 transformers, PAC utilizes proprietary audio transformers for a 1.3 dB gain to compensate for any signal loss that may occur due to additional connections in the signal path.

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Q & A

Customer Q&A

Crutchfield asked  
Why did you buy this?

Playing spotify music thru android phone/tablet while also charging device caused alternator whiiiiiine. Very annoying, many have reported this fixed the problem....we shall see. Test run your gear guys...I thought my original cause was bad amp and bad wiring install. I pulled the wiring and amp and still had the noise...So I am gonna try this noise filter. [ Shannon  May 28, 2017 ]
Our 2008 Prius has a noise issue when using the aux port in the center console with an ipod. We have used this device before in another situation and it is very effective in noise reduction. [ Jim  Dec 21, 2016 ]
After reading the reviews and needing to reduce the noise from my aux port in the car while charging my tablet. [ Pamela  Mar 31, 2016 ]
I get a static sound from my Aux port in my 2007 scion tc when my bluetooth dongle is plugged into the power outlet in the glove box. [ Xavier  Feb 07, 2016 ]
I read the reviews and liked what was said about this item. Can't wait to get it!! [ Jan  Dec 05, 2015 ]

3 questions already asked

I bought this item a while ago and have not used it in more than a year. My recollection is that it did a good job of reducing background noise (which is the problem that I was having - a whistling or high pitch in the background). It reduced sound quality a little but overall I had a better sound experience with the reduction of the background noise. [ STANLEY  Apr 21, 2016 ]
it works very well for me i had a humming its gone now so it works for me [ Henry  Apr 21, 2016 ]
Makes it better, especially at lower volumes. The filter provides a very well-crafted Signal-to-Noise Ratio that dramatically improves the quality; no hiss is heard even when the there is no sound. [ Vernon  Apr 21, 2016 ]
If you purchased the product from Crutchfield, feel free to contact our Tech Support team. They can walk you through the settings on the product and see if there may be a fix. Our toll-free Tech Support number is printed on your invoice, and is also available under the "My Orders" tab in the "My Account" section of our website. If you did not purchase the unit from Crutchfield, then you may want to contact the manufacturer. You can also post your question in our forums: Or try our online support center: [ Krissy  Sep 02, 2015 ]  Staff
Correct, that is how I connected it and it worked. If you were to reverse that connection you would need male/female adapters. [ ROGER F  Jan 22, 2014 ]
Yes, the "output" of the iPod goes into the "input" on the PAC SNI-1/3.5 Noise Filter. The "output" on the PAC SNI-1/3.5 Noise Filter plugs into the "input" of your car stereo. So, you are correct! It works like a charm in my 2005 Mini Cooper S Convertible! [ RONALD  Jan 22, 2014 ]
yes, that's correct. The male connector goes to your Aux port. Good luck, Dirk [ Dirk  Jan 22, 2014 ]
It doesn't matter how you hook it up. I did it both ways and conducted an unofficial road noise test. For me, it made more sense to hook the box up directly to the AUX input on my vehicle. That way I was able to hide the box out of sight and use a longer, more user friendly 3.5mm to 3.5mm male to male cord to hook up my device to the box... Good luck, this item works as advertised. [ DOMINIC PALLONE  Jan 22, 2014 ]

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