Cell phone / radio interference

[Lewis&Clark]

I have a ProClip USA mount in 4R that keeps my iPhone easily accessible and always charging. I also ran a long audio cable from the jack inside the center console through a hole I drilled in the console that feeds it into area underneath the transmission shifter, and then out the side and up to the bottom of the phone/mount where it plugs into the audio jack.

When the audio cable is plugged in, it plays my music through the aux beautifully. When the power cord is also plugged into the phone, there's a not insignificant amount of interference as well.

I'm not an audio engineer, but would love to get rid of the interference sound. Is there anything I can do to mitigate the interference?


dt

 

[BlackWorksInc]

Install a Ferrite Bead?

Ferrite bead - Wikipedia, the free encyclopedia

 

[Lewis&Clark]

Install a Ferrite Bead?

Ferrite bead - Wikipedia, the free encyclopedia

So that's what those things are...

Hmmm. Ordered a few on Amazon; hopefully this will work.

Thanks for the suggestion!


dt

 

[Vetteman15]

I have found the newer IPhones (5 and up) have these issues. My iphone 5 has what sounds like static coming through when playing pandora/itunes via the headphone jack through the aux input. I noticed the static only occures when the phone is downloading data. In reseraching this it appears the 4G (LTE) antenna in the phone interfears with the RCA/aux cables if they are not shielded. One way to reduce the interference noise is to disable the LTE setting on the Phone. This places the phone in a 3G mode and it reduces the noise. My wife's iPhone 4 has no problems and the only difference is it is not a 4G phone.


Hope this helps!

 

[m85476585]

Ferrite beads generally only work for radio frequency interference. You would only be able to hear that if there is something in the car's audio system that modulates RF down to audio frequencies. It can happen sometimes.

If that doesn't work, it may be ignition noise or you could be creating a ground loop in the car's electrical system. If that's the case you need to isolate the audio signal or filter the power. A 1:1 audio isolation transformer could work, or maybe someone makes a power filter for vehicles that would work.
This could help: http://www.amazon.com/PAC-SNI-1-3-5-3-5-mm-Isolator/dp/B001EAQTRI/

re: 4G interference. That sounds like it's internal to the phone, but if a shielded cable helps, that's great. I think practically all aux cables are shielded though.

One tip to make ferrite beads work better is to loop the wire around the bead so it passes through more than once, if you have room. It's also critical that the two halves have good contact if it's a split bead.