PAC SNI-1/3.5 Noise Filter

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

Item #: 127SNI135

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88 Reviews

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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.

PAC SNI-1/3.5 Noise Filter Reviews

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88 reviews
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PAC SNI-1/3.5 Noise Filter

Written By Anonymous, Michigan on Monday, July 13, 2015

Crutchfield Customer Review (What's this?)

Removed alternator whine 100% from Garmin XM radio on my Goldwing.

Did Its Job

Written By Jeremiah S., Arkansas on Monday, March 16, 2015

Crutchfield Customer Review (What's this?)

In a word.....Simple. Plug it up and allow the silence to wash over you. I've used several and they have all been amazing.

Pros: Simple

Cons: None


Written By Satisfied Customer, Chicago on Thursday, February 12, 2015

Crutchfield Customer Review (What's this?)

Worked perfectly!!!

Good Product

Written By Will, Chicago, IL on Monday, January 26, 2015

Crutchfield Customer Review (What's this?)

This device did exactly what I needed it to do. I installed an Audiovox Mediabridge in my 2006 Honda Accord. When I hooked up my external Sirius XM radio to the auxiliary jack on the Mediabridge, it would produce a whining/hissing noise, due to a bad ground wire. The noise was very annoying and made listening to made satellite radio unbearable. Once I hooked up this device the noise was gone. Occasionally, the audio will go in and out, which might just be due to a bad auxiliary cord on my end. Would personally recommend this product.

Alternator noise

Written By Superdog, Lake City AR on Thursday, September 04, 2014

Crutchfield Customer Review (What's this?)

It works an does a great job at it best filter I have ever had good investment if you got a ground noise

Works great

Written By David, Prosper, TX on Tuesday, December 24, 2013

Crutchfield Customer Review (What's this?)

Does what it says.

Works Great

Written By Jim, Maryland on Tuesday, September 17, 2013

Crutchfield Customer Review (What's this?)

Perfect solution to an annoying problem.

Pros: Eliminates ground loop noise when listening to your phone or ipod when the source is also connected to a charger.

Cons: Product is not waterproof. I use it on my motorcycle.

Worked perfect

Written By Mike S, Tomahawk, wi on Sunday, August 11, 2013

Crutchfield Customer Review (What's this?)

I had a terrible noise on the boat radio when I played the iPod and charged it at the same time. I put in the noise filter and everything works fine.

Pros: Worked perfect

Cons: None


Written By cj, Antioch,CA on Thursday, July 11, 2013

Crutchfield Customer Review (What's this?)

Did the trick. Eliminated whine

Pros: Works Great

Cons: Should have gotten sooner

Like everyone says it works seriously!

Written By DjB, Aurora, Illinois on Tuesday, November 20, 2012

Crutchfield Customer Review (What's this?)

This really works and its inexpensive. What a great solution!

Pros: It works really well

Cons: None


Written By AJ, NJ on Thursday, October 04, 2012

Crutchfield Customer Review (What's this?)

For those of you who are running a portable device (for me it's my Sirius S50 radio) and getting crazy interference from the car, such as accelerating the gas pedal or power windows, this noise filter does work. I was doubtful at first, but I took a chance and ordered the unit. Got the unit in the mail and hooked it up in 2 seconds and BAM. No more background whining noise. The only thing that I think it might also affect is the sound. It appears it makes the sound not as rich as the sound was meant to be. Seems to have a tad bit more treble, but not enough to not get this unit


Written By ted, albany ny on Tuesday, May 01, 2012

Crutchfield Customer Review (What's this?)

does that it says it will to. Killed the alternator wine in my 66 Mustang when using my Ipod

Pros: it works

Cons: none

Peace at last

Written By chuckt, Holly, Mi on Wednesday, February 22, 2012

Crutchfield Customer Review (What's this?)

I admit my hearing isn't the best, and to be honest the hum that this eliminates didn't bother me that much. My wife, on the other hand, has great hearing and I could never use my xm radio with her in the car. The high pitched hum would literally give her a headache. After about 20 minutes I would have to turn the radio off. As soon as I plugged this in she said she couldn't hear the hum at all. Now I have peace at last.

Pros: Eliminates that annoying high pitched hum when your radio is plugged into the power socket.

Cons: My only complaint is the cords aren't really long enough to tuck the module away and out of sight.


Written By Toyota Man, MA on Wednesday, November 09, 2011

I have tried just about everything. This is the only thing that really works. NO MORE HUM!!! PRICELESS!!

Pros: small, compact and a great price. this thing really works. 10 stars in my book. no more hum. buy it


Written By Ray, New York, New York on Thursday, November 03, 2011

Crutchfield Customer Review (What's this?)

This was so easy to install in my Lexus IS250's aux input. Whenever I had my iPhone hooked up to both my car's aux input for music and the cigarette lighter for power, I got this annoying alternator whine. This PAC SNI-1/3.5 Noise Filter solved the problem instantly! Many thanks, Crutchfield, for letting me know this product even existed!

No effect on audio feedback

Written By KeithN, Columbus,OH on Thursday, November 03, 2011

Crutchfield Customer Review (What's this?)

Sounds like a great idea, but it didn't work. I'm getting feedback in my 2010 Mazda 3 when I have my iPhone charging and plugged into the aux at the same time. This product did nothing to reduce the feedback.

Poorly made, cheaply produced

Written By BWsquare, Los Angeles, CA on Saturday, August 13, 2011

Can they not make these things right, ever? This is the second piece of car audio equipment I've bought in the past few days that is broken. Loose wire causing crackle and shorting. Poorly manufactured. Lame.

Got rid of the hum

Written By DL, Chicago on Tuesday, June 21, 2011

Crutchfield Customer Review (What's this?)

Whenever I listened to my mp3's while driving, I would get this annoying hum if a) the phone was plugged into the Aux port AND b) the phone was connected to the car charger. The hum disappeared if i disconnected the car charger. This was fine for short trips, but not for longer road trips. I heard a ground loop isolator would solve the problem. Plugged it in and voila, no more hum.

great simple solution

Written By bdmcfarland7, Centerville, OH on Sunday, February 20, 2011

Crutchfield Customer Review (What's this?)

This worked great for me. I run my Sirius satellite radio directly into an
auxiliary input adapter in my car to avoid using the FM transmitter. I had a
constant buzzing/whining sound coming through the speakers, and this device
completely got rid of it. It was a no hassle install and well worth the money.
Consider me a satisfied customer.

Bad Sound quality

Written By Tan, Atlanta, GA on Thursday, October 14, 2010

Crutchfield Customer Review (What's this?)

I purchased this product because it got such high rating. However, I was disappointed in the sound quality. It does eliminate the engine whining noise. It also eliminated the low and high frequency from the music. In that respect, if you only use this for talking on the phone then this product works just fine for you. However, if you want to listen to the music from your phone, the music may not sound very good. I found out the hard way that the solution is much easier then you think. When this product didn't work as good as I wanted, I then look for alternative. All I have to do was to make sure the negative wire to the cigarette lighter is properly grounded.

Works like a charm!

Written By Brice, Monroe, MI on Wednesday, June 16, 2010

Crutchfield Customer Review (What's this?)

I use my iPod Touch as the user interface for my XM radio along with the dock that connects the antenna and powers the iPod, etc. The fm transmitter of the dock is not very effective, so I used a separate, much better transmitter. However, when I connected the two, the ground loop was obnoxious. After taking less than a minute to plug in this noise filter, the ground loop was gone, and my sound is impeccable once more!

Excellent product, excellent service.

Written By Alberto, Miami, FL. on Tuesday, June 08, 2010

Crutchfield Customer Review (What's this?)

Bought it for my Mazda 3 and worked great. Guys at customer service were very helpful making my payment with international credit card. Thanks a lot.

Worked as advertised

Written By Terrance, Dearborn, MI on Friday, April 23, 2010

Crutchfield Customer Review (What's this?)

Golly, what a difference! Instead of the insanity created by constant alternator whine, I now have a clean signal. With regard to those that say they lose some fidelity, I didn't really notice any loss. The signal was so bad anyway, how would you be able to tell?
Thank you Crutchfield. Good service and speedy delivery.

Excellent Product and Service

Written By David, Ottawa, CA on Tuesday, December 08, 2009

This filter does exactly what it is supposed to. All the noise when using the
AUX IN, that I've suffered for the past 3 years, has now gone. Period. Service
buying thru the Canadian Web site was excellent: ordered Sun Dec 6 @10 am;
delivered the morning of Tues Dec 8.
An Excellent company to buy from.

Negatively affects sound quality

Written By Scott, San Diego, CA on Monday, November 23, 2009

Crutchfield Customer Review (What's this?)

I purchased this filter to eliminate background hissing noise caused by a ground
loop when connecting my iPod to the DC power jack of a 2006 Prius. It got great
reviews, so I was surprised and disappointed to find that it negatively affects
the sound quality of my system. This is most noticeable at higher volumes and
at certain bass frequencies; however it is also noticeable at any volume
whenever the sound becomes very full. This seems to overload the circuitry and
produce crackly noises (similar to blown or overdriven speakers). Furthermore,
I've noticed that music generally sounds less pure even when this particular
distortion is not evident (I've unplugged and replugged several times to make
sure that this isn't simply in my head.). I'm a discerning listener, so both of
these issues are annoying. So, in summary, although this product eliminated my
ground loop problem, it introduced other annoying problems. As a result, I
unfortunately can't recommend it.

Works as advertised

Written By Chuck, Moore, OK on Tuesday, October 27, 2009

Crutchfield Customer Review (What's this?)

Used on my Peterbilt truck. Works perfect. I first tried a new audio cable with no luck,
and was almost ready to completely rewire everything when I came across this cable. I
have no complaints. If you have a noise problem, buy this!

Wow. It just plain works.

Written By John M, Arlington, Va. on Thursday, September 24, 2009

Crutchfield Customer Review (What's this?)

I had real bad alternator whine when I ran my Sirius through the 3.5mm jack of an AudioLink adapter that goes into the CD changer port of my '07 Miata's Bose HU.

I'm usually worried about passive filters and what they can do to audio quality but this little box totally wipes out the whine AND leaves the signal unchanged IMO. In fact there's a touch of extra gain. I must assume that the few people who reported frequency response problems must have received a defective box. I hope they all first called Crutchfield and tried a replacement before blurting out those bad reviews.

I'll slightly qualify my review by saying my alternative to this setup is the Sirius FM transmitter. So even if I lost a little frequency response with this box in-line, it is still far better sounding than my alternative.

Does what it says it does!

Written By Kevin, Pell, City Alabma on Friday, May 29, 2009

Crutchfield Customer Review (What's this?)

I have XM connected to a boom box. The stereo was making allot of hissing noises and some high pitch sounds. Twice there was an audio spike that burnt up the audio board in the Delphi receiver. I can tell a HUGE difference since purchasing this little gem. If you have XM and are using the line out jack, you want this!

Great product!

Written By meskin, Washington, DC on Friday, May 15, 2009

Crutchfield Customer Review (What's this?)

I use this for my portable Inno XM player and it works like a charm. Before I used it, I had some nasty sounding ground noise whenever I 'd hook up the Inno to my "Aux In" on my head unit. I could always crank up the volume and drown the noise out, but I shouldn't have to do that.

This thing effectively eliminated all ground loop noise. Awesome product!

PAC SNI-1/3.5 Noise Filter

Written By James, Apison, TN on Saturday, May 02, 2009

Item does exactly what it is supposed to do. I installed it in the auxiliary input line and it eliminated the high-pitched alternator whine that had plagued my for several weeks.

This little thing is a savior!

Written By Dave, Quincy, IL on Wednesday, April 29, 2009

Like everyone else that wrote a review for this, I had a whining noise when I had my iPod plugged into the 12v outlet in my SUV. It drove me insane until I came to Crutchfield and did a search and came across this magical little devise. ( I have a Dual brand stereo with the rear auxiliary input with iplug connector) The noise was only present when my iPod was plugged into 12v power, so I knew it was either wiring interference or alternator whine.....the PAC Noise Filter took care of it ALL....literally took me 2 minutes to plug it into my stereo cable running from my iPod to the iPod connector that came with the Dual stereo (or auxiliary input jack on some stereos) and tucked the PAC Noise Filter behind my stereo in the dash. Great item for great price!

Works with laptop hooked up to home stereo

Written By Bob, Austin, TX on Friday, April 24, 2009

Crutchfield Customer Review (What's this?)

Excellent widget. I was tring to listen to music from my laptop on my cheap Sony home theater stereo by running a line from the laptop headphone jack to the stereo's audio in line. It was so noisy and buzzy that I couldn't stand it. I mean really really loud. This filter eliminated ALL the noise, and has the right 1/8" jacks on both ends so I could plug it right in. Very very pleased.

Nothing short of Spectacular

Written By Shantie, New York, NY on Wednesday, April 01, 2009

Crutchfield Customer Review (What's this?)

First off I have never writtten a review on anything before.

To preface I bought an adapter for iPhone and iPod, for my iphone and Lexus IS250 AWD. As soon as Plugged everything in there it was the hissing, winding sounds coming from the ground. Frustrated i began searching the internet for an isolator, and I landed here. had it over nighted and justdropped it into the car.

Upon starting the car with fingers crossed I waited to hear even the slightest of noise coming from the speakers, NADA.

This unit has completely gotten rid of and feedback I once had.

PAC SNI-1/3.5 Noise Filter

Written By Damian, Atlanta, GA on Friday, February 06, 2009

Crutchfield Customer Review (What's this?)

This little device is just what the doctor ordered! They are easily taken apart to shorten the leads or add jacks. The little amplifier in the circuit replaces the audio volume lost to the transformer.

I am using them to isolate audio circuits to an Autocom intercom on a motorcycle. They work flawlessly.

Solved noise problem with iPhone in Prius

Written By Allen, Des Moines, IA on Saturday, January 17, 2009

Crutchfield Customer Review (What's this?)

I have a 2007 Toyota Prius. When I hooked up my iPhone to the AUX IN jack, I encountered interference noise. Some web searching led me to various forums suggesting this gadget from Crutchfield. I purchased it, hooked it up, and the noise went away. Perfect solution.

The only thing I wish it had was two male plugs instead of a male/female. That way, it could be used to directly connect between the device and the AUX IN jack without me needing to buy a separate cable. For others, though, this path-thru arrangement may be ideal.

Works perfectly

Written By acepelon, Austin, TX on Tuesday, January 13, 2009

I just got this based on reviews here on Crutchfield. Couldn't find it anywhere in town so I was hesitant because I didn't want to have to return it.

I drive a 2006 Prius and this thing works flawlessly. Now I can charge and use my iPhone/ iPod classic without that horrible whining noise- and no I don't mean my wife :-)


Written By richard, Hammond, LA on Saturday, November 15, 2008

I was skeptical at first, but i decided to give this product a try after reading
the reviews. i have a Mazda 3, and my Sirius Starmate 4 was being
connected directly to the AUX input in the center console. Had alternator
whine in the system since day 1. I tried re-routing all of my cables to
seperate them from noise producing conductors with no luck. i installed a
Sirius hardwire power supply to make sure everything was grounded with
no luck. Then i put in a power line noise filter with no luck. Even tried
multiple sets of magnetic ferrule chokes with zero difference as well. Then i
bought this noise filter...

This item was the first product i have ever seen completely eliminate 100%
of the alternator noise!!! BUY IT!!!! IT WORKS!!!!! Don't know how it works,
but it did the job. I wish i had known about this a long time ago. I spent 8
months fighting to get rid of the noise. Tell your friends and family, this will


Written By Joe, Arizona on Wednesday, October 22, 2008

Crutchfield Customer Review (What's this?)

Bought this after trying several others. I tried the power filters and audio filters, some costing twice as much as this one. I finally tried this one and WOW! It worked. I have it installed between the satellite radio and the aux input of my 2004 Honda Goldwing. I had the whine from the alternator. Now I don't. If you need to get rid of alternator whine, this is it! Thanks Crutchfield for great prices and fast shipping.

Works great!

Written By Gnarlodious, Santa Fe on Monday, October 20, 2008

I had a persistent problem with static noise when music was not playing or the computer was sleeping. This little gizmo fixed it real good. Now perfectly quiet.

PAC SNI-1/3.5 Noise Filter

Written By AL, Kentucky on Saturday, October 11, 2008

Crutchfield Customer Review (What's this?)

Awesome product. Works great as previous reviews have stated. Had a Sirius radio plugged in acc. jack and had an alternator whine, especially on news channels. This solved it and very easy to install.

PAC SNI-1/3.5 Noise Filter

Written By Rob, Boston MA on Thursday, October 02, 2008

Crutchfield Customer Review (What's this?)

Great product! It worked as it said it would. I used it to filter out an annoying hiss from my XM radio to a new radio I had installed in my Sequoia. My issue was easily and instantly resolved!

Works, but...

Written By crb, St. Louis, MO on Saturday, September 20, 2008

Crutchfield Customer Review (What's this?)

Took the engine noise out of the line, but also took all the lows and highs out also.

Works like a charm!

Written By Lester, Mason, Ohio on Tuesday, September 09, 2008

Crutchfield Customer Review (What's this?)

Our new 08 Kia Optima has an awesome sound system with an AUX input. When I plugged the satellite radio into the AUX jack there was a terrible whine that changed pitch with engine RPM. It was most noticeable on talk channels and quieter music channels. I plugged this little gem in and the noise was totally gone. There was no noticeable degradation in the sound output.

It works

Written By Rahil627, Chesapeake, VA on Thursday, August 28, 2008

Crutchfield Customer Review (What's this?)

I have a 2007 mazda 3 that came with an AUX connection. When I attached the charger, it would generate audible interference...this solved the problem.

This really does what it is intended to do....

Written By Maxwell, Owings Mills, Md on Friday, August 22, 2008

Crutchfield Customer Review (What's this?)

I have used this product several times, and it as not let me down once. I recently used one to get rid of alternator whine, and various other noise in a system. I decided that this was a much cheaper option than pulling various parts (and possibly the engine) out to get to a very hard to reach alternator to install a capacitor. Well worth the money!!!!!

Gets rid of the buzzing sound

Written By Gardner, Philadelphia on Thursday, August 07, 2008

Crutchfield Customer Review (What's this?)

I have a 2007 Toyota Camry SE, and have always been annoyed that I can't plug in my XM radio directly into the aux jack (high-pitched whining sound occurs when I do). It was almost like the connection wasn't grounded. Very frustrating. I had to use the FM station converter, and the sound quality was not that great.

THIS PRODUCT IS AN AMAZING, EASY AND INEXPENSIVE FIX!! For less that $20, plug your XM radio into it and then into the aux outlet for no static noise and good sound. HIGHLY RECOMMEND!!


Written By Nura, Philadelphia, PA on Wednesday, June 25, 2008

Crutchfield Customer Review (What's this?)

Doubters beware! This product is phenomenal. I own a Mazdaspeed6 and installed a product called audiolink which adds an auxilary port to my car. I have a bose head unit. When i hooked up my ipod to the audiolink device, there was no static at all. Then, i hooked my ipod to a power source within the car, and thats when the static noise kicked in. It was loud and just irritating. I then bought a Ground loop isolator and it was worthless!

I finally came across this device from crutchfiled and all I gotta say is, I am amazed. It has gotten rid of ALL static noise.

NOTE: I am not some one who usually signs up on websites to write reviews. But, after months of frustration and finally finding a product that works, I felt the need to spread the word. all I gotta say is BUY IT!


Written By Scott, Orlando, Florida on Friday, April 18, 2008

Crutchfield Customer Review (What's this?)

All I can say is that 5, that is right FIVE filters later, I found the solution. This thing is amazing. Not only within the same price range as the previous filters tried from local car audio installers and another online vendor, but this actually works. This was being used in a carputer application and I was getting TERRIBLE ground loop noise on the analog audio line. Even at low volumes, I was hearing the ground loop. Now, even at the higher volume, it sounds the way it did at the lower volume. There is no way I could ever turn the volume up that loud. So at the normal range that I would listen at, you cannot even hear a hum. Awesome job PAC. Crutchfield also came through with next day delivery of the goods, even when only ground shipping was selected. I guess they have a local distribution center. Awesome!!!

Problem Solved!

Written By Chris, Chicago, IL on Thursday, April 17, 2008

Crutchfield Customer Review (What's this?)

If you are experiencing the alternator whine problem as myself and the rest of the reviewers here were, this is the product for you.

After installing the SNI-1/3.5 Noise Filter in my car for my iPod (which took about 5 seconds) the alternator whine was not just reduced, it was completely GONE. Also, there was no loss of sound quality. As another reviewer stated, I did notice a little reduction in the "highs" but it wasn't anything a little adjusting of the equalizer couldn't fix.

I highly recommend this product to anyone with the alternator whine problem. I also highly recommend Crutchfield. Great prices and fast shipping. It took 2 days for me to receive my order with standard shipping.

Works Perfectly

Written By James, Ohio on Monday, April 14, 2008

I recently installed Sirius radio in my 2008 Toyota Solara. Unlike previous vehicles I owned, the Solara has an auxiliary input jack, which is the best method for feeding audio into your factory system from an external source.

The problem was that I had the Sirius wired into the auxiliary power input outlet right next to the audio input and there was terrible alternator whine.

I installed this puppy in 15 minutes (it's behind my dash board) and now my audio is crystal clean.

Thanks Crutchfield.

PAC SNI-1/3.5 Noise Filter

Written By George, Burlington Vermont on Friday, February 29, 2008

Crutchfield Customer Review (What's this?)

This product is amazing...I was totaly blown away with how well this resolved my hissing and atlternator whine. Simply plugged it in like the directions said and it was GONE!

I used this on my 1997 Honda Valkyrie motorcycle. I was trying to run a Sirius Satelite reciever and couldn't stand to use it because of the whine and hissing.

I love this really works. Now I can ride all summer and enjoy my Sirius radio.

I was really frustrated!

Written By Joseph, Englishtown, NJ on Saturday, February 16, 2008

Crutchfield Customer Review (What's this?)

I installed a Garmin Nav system (with built-in MP3 and XM ) as well as an IPOD connector into my Mazda 6 2006 . The IPOD was GREAT! The AUX i/P for the Garmin (MP3 and XM) was terrible - hissing and engine whine - really bad! I bought a ground loop device - no good. I bought another ground loop - no good! I found this site and these reviews and had serious doubt! I went for it, just installed it and it's GREAT! All my problems are GONE! Yes it does reduce the quality of the highs a bit - not by much! It's the best thing since sliced bread. Joe

It Works Great!

Written By Derek, Los Angeles, CA on Tuesday, January 29, 2008

Crutchfield Customer Review (What's this?)

Like many of the other reviewers here, I was running Sirius satellite radio (Starmate Replay, hard-wired via a stereo mini-jack cable) through my aux port on my 2007 Toyota Camry. The high-pitched whining, which varied in pitch as the engine RPM varied, was so bad that I didn't want to use the Sirius radio anymore. I had tried a "shielded" cable from Monster but it made no difference. I bought this product from Crutchfield after reading all of the reviews. It took about 10 seconds to install. Now I can't detect any whine at all! It works equally well when my wife's Ipod is attached. Definitely worth the money, since anything playing through the aux port was basically unlistenable before, unless the car was at idle. Now it sounds great.

good product

Written By dan, Charlotte, NC on Sunday, January 27, 2008

Crutchfield Customer Review (What's this?)

I wired a sirius Sportster 4 into a AUX in device in my 06 4Runner. There was a hum. This filter completely removed it.

No more whine

Written By Nicholas, P'cola, FL on Wednesday, January 09, 2008

Crutchfield Customer Review (What's this?)

I have never seen a noise filter work this well. I had serious alternator whine with my new Sirius radio plugged into the aux input on a iPod DiCE in my BMW. There is now only the faintest whine, but you have to turn the stereo all the way up and the sat all the way down to just barely hear it. At normal listening levels it is completely gone. Even on talk radio!!!

Ground Loop noise gone for good!

Written By pakong, Hampton Roads, VA on Wednesday, November 07, 2007

Crutchfield Customer Review (What's this?)

I'm using a MIO C520 in my 2007 RAV4 LTD plugged in to the AUX jack.
I've tried ground loop isolators for over 15 years and nothing works as effectively as this unit. I expected the noise to be reduced but instead it was completely gone or not discernable to my ears even with amplification. This product is truly amazing.

No more whine!

Written By Damond, all 48 states on Sunday, September 23, 2007

I'm an over the road truck driver. After getting a radio in my truck with the aux input, I plugged my Sirius receiver in... Oh Dear God. It was almost as brutal as driving through the desert with no radio at all! I knew there was one place and one place only to look for the fix!

Thanks Crutchfield!!!

PS. I've been asked several times out on the road, what can be done about this on the CB. I tell them

No More Whining

Written By Bill, Philadelphia, PA on Wednesday, August 22, 2007

Crutchfield Customer Review (What's this?)

After reading several reviews, I decided to buy this item since I've been experiencing a high pitched whine in my speakers as I drive (the faster I went, the louder it became). I admit, I was doubtful about my purchase at first. After receiving my package (incredibly fast BTW), I installed the module and was pleasantly surprised with the sound quality. Even as I cranked up the volume, there was no distortion whatsoever! (To me) it sounded like i popped a regular CD in my player. I would recommend this product to anyone who has a satellite radio or mp3 player plugged into an AUX port & using a cigarette lighter adapter. I couldn't be happier with my purchase!

PAC SNI-1/3.5 Noise Filter

Written By nate, enfield ct on Friday, August 10, 2007

Crutchfield Customer Review (What's this?)

I bought a toyota rav 4 2007 with the aux input. I have had sirius radio for over 2 years, and have waited for the day that i could bypass the Fm transmitter. But to my disapointment, that annoying hum that everyone describes in great detail blaired through my system. After doing my research I came across this product, ordered it and 24 hours later it was at my doorstep....I hooked it up and wallahhh! NO MORE NOISE!!!!!! crutchfield rules.

You won't hear me whining anymore! ;)

Written By Lisa S., Willoughby, OH on Monday, August 06, 2007

Crutchfield Customer Review (What's this?)

I give Crutchfield & This Product 5 Stars!!!!

1) Quick Shipping.
2) Fantastic Customer Service(up to date status,etc.)
3) Extremely Helpful Customer Service Reps.
4) Easy as cake to install.
5) Product works perfectly!!

*If you are hesitating about purchasing this product, DON'T...The quicker you order this product the quicker you'll be in heaven listening to your Sirius Radio or iPod. This has put to rest so many frustrations.

No more whine....Hallelujah!

Written By Irene, Staten Island, NY on Friday, July 06, 2007

Crutchfield Customer Review (What's this?)

I have a 2006 VW Touareg with the built-in AUX ports in the center console. Using any of my MP3 players or my Ipod with the RCA cables in the AUX and also charging thru the 12v adapter caused an awful whining noise which seemed to be speed dependent....the faster I went, the louder the whine. If I unplugged the charger and used the battery only, the noise would disappear.

This very simple-to-use device did the trick. I can now play and charge at the same time in peace!

A World of Difference!

Written By Chris, Arlington, VA on Thursday, July 05, 2007

Crutchfield Customer Review (What's this?)

I'm so happy with the noise-reduction this filter achieved!! I run my iPod through the AUX-in jack in my Prius, while powering the iPod off of the AC/"cigarette ligher" outlet. The hum/whine that was constant before, is now completely gone. (I'd used an iPod FM transmitter before for about 5 years, while powering the iPod off the AC outlet in my Honda Accord; when I got the Prius, with that built-in AUX-in jack, I wanted to eliminate the FM transmitter entirely and stop searching for "empty" FM frequencies. But I was disappointed with the power-outlet hum, right away.)

My first filter arrived and seemed to be fine for a day, until I hit a bump in the road, that jostled all the contents in my armrest compartment, and the sound suddenly got all watery and thin. I thought the iPod was dying, but went through the whole setup, from iPod to filter to 1/8" male-male connection wire; traced the problem to to a loose internal wire/short, where the wiring meets the female jack head on this filter. Crutchfield immediately sent a replacement, and it has been perfect.

I definitely recommend this product!

PAC SNI-1/3.5 Noise Filter

Written By gfreek, Attica, NY on Wednesday, July 04, 2007

Installed Sirius Starmate 4 in new 07 Toyota Rav 4, connected to AUX input. The humming noise that changed pitch with engine speed was terrible. I found this searching the net for filters, ordered 2, one for Toyota and one for future use. It works great, highly recommend this product

Completely eliminated hissing (my car) & whining (wifes car)

Written By Robert, Austin, TX on Friday, June 15, 2007

Crutchfield Customer Review (What's this?)

My wife and I both have 2006 Scion xB's... we also both have Sirius Starmate Replay units connected to the factory aux port.

My wifes car had a horrible engine whine & my car had a hiss (and slight whine). I bought two of these, installed them in both cars, and the sound is now crystal clear. EASY install - definately recommended.

PAC Noise Filter-Worth Every Penny I Paid for it!

Written By Frank, Pittsburgh PA on Thursday, April 19, 2007

Crutchfield Customer Review (What's this?)

My girlfriend and I both have Sirius Radio's. We have a Nissan Altima and an Xterra. I installed the Radios and hardwired them using RCA to mini-jack cables. After the install, there was a LOUD whining noise heard through the speakers in both of our cars. (My Altima was much worse than the Xterra.) The noise got even worse while accelerating and driving at highway speeds.

After I almost returned my radios, I found this noise filter on Crutchfield. I decided to buy 2 of them to see if they would fix the problem. After I installed them in both cars, the noise completely dissappeared. My Sirius Radio now sounds like I am listening to a CD! No fuzz, hissing, or whining whatsoever.

I completely recommend this to anyone who has a whining noise when listening to their iPod or Satellite Radio in the car.

Perfect for Mazda 3 owners

Written By Kristina, Maryland on Friday, March 23, 2007

Crutchfield Customer Review (What's this?)

I have a 2007 Mazda 3 with an AUX jack/Bose system/amp. If I used my iPod with a 12v charger I would get unbelievable engine noise/interference through all speakers. I had almost given up hope until I found this product. Got it yesterday and it works like a charm- the noise is 100% GONE. The best part about this is that no modification has to be made to the car at all, and since my AUX jack is in my center console- you don't even see the very small box.

As far as I'm concerned.. every Mazda 3 owner with an AUX jack should purchase this right away. This is a known problem for the car which has been posted in a few Mazda 3 forums.

Just as Advertised

Written By Michael, York, PA on Monday, January 29, 2007

Crutchfield Customer Review (What's this?)

I contacted Crutchfield with a feedback problem and they immediatley suggested this product. Ordered it one day, received it the next, and I am now listening to my Sirius radio in CD quality (or close enough for my untrained ear).

PAC SNI-1/3.5 Noise Filter

Written By Raul, north bergen, NJ on Tuesday, January 23, 2007

This thing works great!!!!!!

Noise Filter

Written By no, Saugus, CA on Friday, January 19, 2007

Crutchfield Customer Review (What's this?)

My expertly packaged order arrived today ahead of schedule. The item was as advertised and performs it's function perfectly. I installed satellite radio about a week ago in my '06 Scion TC. I plugged it directly into the auxiliary jack in the armrest and got ignition noise that was unacceptable. I researched my issue on the web and learned about ground loop noise isolators. I was directed to your web site when I searched the previously mentioned item. I could not be more pleased with the service I have received or with the item I've purchased.

Exactly the producy you're looking for!

Written By Joseph, Boston,MA on Tuesday, January 16, 2007

Crutchfield Customer Review (What's this?)

I recently purchased Sirius with a life time subscription. I was very disappointed with the sound quality at first. I had a terrible electronic buzzing(obviously a ground related problem) in my personal car and a fainter, yet similiar sounding noise in my work truck. I initially thought the problem was the satellite receiver and actually went through the trouble of sending it back as defective. When the replacement receiver showed the same exact problems, I knew for sure it was a ground loop related problem. I was going to take my car to a stereo store to have a ground loop isolator installed at a much higher price when the sales rep. mentioned that they get there parts through Crutchfield. I decided at that point to research it myself. That turned out to be a really great idea. I read the reviews written prior to mine and saw the overwhelming positive feedback so I figured that this was going to solve my problem. I'm happy to report that it did and then some. Not only has the humming disappeared but I truly believe that over all the sound quality is much improved. The sound I was getting in my work vehicle was tolerable but I now take my noise filter in my work truck everyday becaue the difference is noticably better. Sirius should seriously (pun intended) consider installing a similiar noise reducer directly in there next generation of players. Consumers would be noticably happier. Overall I'm extremely satisfied with this product.

Sirius S50 MUST HAVE

Written By swagge1, Baton Rouge, LA on Thursday, January 11, 2007

Crutchfield Customer Review (What's this?)

1998 Nissan Frontier

I had the same sypmtoms that basically everyone else mentioned. Whining in speakers that coresponded with RPM. The noise could only be heard when using my Sirius S50 with the AUX port on my CD player. FM radio was fine. It was only when the cigarette lighter was plugged in that the noise would come. After plugging in this filter the noise was 100% gone!! I really can't tell if any sound quality has been lost using this filter either. It is a MUST have if you're experiencing AUX problems from your cigarette lighter charger.

Made matters worse

Written By Bill, Cleveland, OH on Monday, January 08, 2007

Crutchfield Customer Review (What's this?)

Ordered this to try and clean up the alternator whine I was getting while using my Harmon Kardon Drive+Play via my factory aux input. It didn't eliminate the alternator whine but did eliminate most of the bass from my ipod! A waste of money and a disappointment.

The best

Written By rude dog, the OC on Friday, January 05, 2007

I have a 2007 Toyota Prius. The car is full of electrical wiring and crap. I installed xm radio and it plugs into the cars existing auxillary jack. There was a horrible hiss coming from the power source (cigarette lighter). The tech support at Crutchfield told me that this device may not work because it was used more for a "whine" noise (the type that gets louder as you accelerate). I bought it anyway and it came very quickly. This device boosted my signal and eliminated the noise instantly!!!!!!!!!
Headache gone.

No more feedback through AUX port

Written By Michael, Murfreesboro, TN on Friday, January 05, 2007

Crutchfield Customer Review (What's this?)

Scion tC with Sirius using AUX port.

Using my Sirius radio through my AUX port was quite annoying. There was engine/transmission feedback (a whine or buzzing noise) when using the Sirius radio through the AUX port and powered by the cigarette power adapter. My iPod had no feedback/whine. Bought this unit and the whine/buzzing is completely gone. Recommend this to anyone that has a AUX port in their vehicle especially if using a satellite radio.

Worked perfectly

Written By Tony, Boston, MA on Thursday, January 04, 2007

Crutchfield Customer Review (What's this?)

After trying to connect my laptop to my receiver, I was hearing a very loud hummmmmmm. After reading reviews online, it was pretty clear I was listening to interference caused by a ground loop. I purchased this product based on the multiple good reviews and It worked perfectly as soon as it was plugged in.

Even at extremely high volumes, the sound is crystal clear with no hissing or this product with confidence!!

PAC SNI-1/3.5 Noise Filter

Written By Sam, New York on Monday, December 04, 2006

Crutchfield Customer Review (What's this?)

Noise Filter / isolation transformer, worked perfectly

It works

Written By Jason Fine, Northeast on Tuesday, November 14, 2006

Crutchfield Customer Review (What's this?)

I was getting noise/whine when connecting my plug-and-play satellite radio to the Aux-In on the back of my head unit. This whine was only there with the car-powered devices, not battery powered ones. As a last resort I tried this unit on the Line-out from the satellite radio and it completely eliminated any whine. The only problem was that it came with the exact opposite gender connectors on it from what I wanted. The line out on my sat radio required a male plug (this unit came with a female input) and my aux in cord from the head unit was already male (the output on this unit is male) so I needed a female-female coupler to hook it up. Make sure you dont hook it up backwards or you lose its built-in amplification. But once its hooked up it works great!

PAC SNI-1/3.5 Noise Filter

Written By Mike, Reno,NV on Thursday, October 19, 2006

Crutchfield Customer Review (What's this?)

The aux jack in my mazda 3 had such a bad whine when using my Sirius One hooked to it I almost couldn't stand to listen to my radio. This product worked perfectly, taking away all noise. I will definately purchase another one for my truck.

Crutchfield rocks, and so does this.

Written By Justin, Frederick, MD on Wednesday, October 18, 2006

Crutchfield Customer Review (What's this?)

I was all excited to use an iPod in my new Mazda 3, but after plugging it into my AUX and cigarette lighter ports, there was an annoying high-pitched electronic noise along with the music. It was not a hum or alternator noise, but rather EMI dumped to ground by the iPod's circuits.

This filter came highly recommended, but I still had some trepidation about ordering it; most such products, if they work, cause bass roll-off, muddiness or other sound degradation. After I received it (overnight with standard shipping!), I can say very happily that it not only eliminated the noise but did so without any adverse effects on the sound (as far as my untrained ears can tell). Bass is still deep and controlled, and treble & midrange sound as good as ever.

This tiny wonder is also the only ground loop isolator I've found anywhere that has mini-stereo plugs, which is an incredible boon for my application. Don't hesitate to buy it now!

No more whining

Written By Robert, Bay Area,CA. on Saturday, September 30, 2006

Crutchfield Customer Review (What's this?)

I have ceiling mount dvd player which I recently connected to aux input on my Dual 7710 car stereo.Dvd audio sounded fine when truck wasn't running but as soon as I started motor the whining noise was horrible.I check all the grounds,wiring connection and installed a couple different noise filters, nothing worked.Until I purchased the PAC SNI-1/3.5 Noise Filter.Im very impressed with this product not only did it eliminate whining noise but Installing the PAC SNI-1/3.5 Noise Filter took less than a minute.

Great Product!

Written By Ian, Washington, DC on Friday, September 29, 2006

Crutchfield Customer Review (What's this?)

When I plugged my iPod into the aux input of my new Saab, I had engine whine. I picked up this mini-jack ground loop isolator, plugged it in between the aux input and the line out and the whine was gone. How simple!! It worked like a champ.

Highly recommended.

Bad Little Box

Written By Packard, Florence, SC on Wednesday, September 20, 2006

Crutchfield Customer Review (What's this?)

This thing is perfect for the alternator whine or pitch that you get from connecting aux's to your system. I had this issue in my suburban with dvd player output and didnt know how to correct it, but now I do. This worked perfect for my 4Runner's aux input in the center console. I was installing Sirius and it was terrible sounding with the high pitch and buzzing, but this box cleared it up immediately! Great Product. Come to the right place....Crutchfield.

I was doubtful, but it worked wonderfully

Written By George, Groton, Ma on Friday, July 21, 2006

Crutchfield Customer Review (What's this?)

I had what I guess now was alternator noise in my car - lots of whining and buzzing. I was trying to use a portable DVD player powered by the 9V jack, with the audio output going to an FM transmitter, also plugged into the 9V jack. Now that I think about it... definite loop there.

Anyway, the noise rendered that setup unusable. I had been using a battery powered FM transmitter (worked OK) which had to be replaced due to cable fatigue (came apart). I replaced it with an iRock FM transmitter which is 9V power only, no batteries.

I put this filter between the DVD audio out and the FM transmitter audio in and the noise is gone. Highly recommended.

PAC SNI-1/3.5 Noise Filter

Written By allenc3, Green Cove Springs Florida on Friday, February 10, 2006

Crutchfield Customer Review (What's this?)

Just installed $20,000 worth of avionics in my Grumman Tiger (aircraft). As I have an XM Radio / Sat Weather System, I wanted to run the Sat Radio Audio through the aircraft intercom system. Got a very high pitched noise when plugging in. Tried everything I could think of to get rid of this noise including expensive alternator filters, etc. Stumbled on this product by accident. Took every bit of alternator whine out of the system. Great Product.

Have spread the word to other pilots who are trying to interface their new Garmin 396's into their plane intercoms.

Exactly as advertised

Written By edward, Huntington WV on Sunday, January 15, 2006

Crutchfield Customer Review (What's this?)

Excellent! I purchased this filter for my gpsmap 396 in my airplane and it completely removed the alternator noise. I am completely satisfied and I have purchased another one for a new audio device in the same plane.

Piper Warrior 1974

Scion aux port buzzing

Written By glen, San Diego, CA on Friday, December 16, 2005

Crutchfield Customer Review (What's this?)

I have portable Sirius satellite radio, which I plugged into my Scion's "AUX" port. Terrible buzzing at idle, and alternator noise. Bought this ground loop isolator... all noise is GONE. Works great.

PAC SNI-1/3.5 Noise Filter

Written By Gene, Mount Holly, NJ on Monday, December 12, 2005

Crutchfield Customer Review (What's this?)

I bought this because I use an MP3 player and XM music in my airplane, but it was totally unusable due to whine and whirl noise. This product fixed that 100%! I highly recommend it.

'71 Cessna Cardinal RG

Works great!

Written By Cosgrach, Bay Area. CA on Tuesday, September 27, 2005

Crutchfield Customer Review (What's this?)

This thing works great! I've ordered several to help deal with ground loops in both the car set up and when connecting my computer to the home amplifier. No more whine or 120Hz humm!


Hands-on research

What's in the box?

Download owner's manual

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

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.

Our Product Research Team

At Crutchfield, you'll get detailed, accurate information that's hard to find elsewhere. That's because we have our own in-house Product Research team. They verify what’s in the box, check the owner's manual, and record dimensions, features and specs. We stay on top of new products and technologies to help people make informed choices.

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