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trayson
03-27-2015, 06:02 PM
So, I've been getting some noise when using my phone for an audio source.

I have a car dock for my phone that has a micro-usb that slides into the phone for audio and charging. The dock has a micro usb plug on the back as well as a 3.5mm outlet.

I have a 3.5mm cable (just a cheap one I had laying around) that goes from the car dock to the aux input of the WS420SQ.

I also have a car charger going into the car dock's micro usb.


I would get noise on my system (like the same kind of sound speakers make when they are getting GSM interference). So I tried unplugging the 3.5mm cable from the car dock and plugged it directly into the headphone jack of the phone. That seemed to help on last weekend's trip.

Yesterday I was getting noise in my system again and the "solution" was to unplug the car charger (which was plugged into one of the boat's 12v cig lighter style sockets).

I've heard that there's some "ground loop" stuff going on. I'm curious what's going to be the best way to address this.

I'd like to still use the car dock if possible, because it's nice to have something holding my phone as I'm driving and to still have the ability to change songs and stuff (rather than keep it inaccessible in the glovebox).

I am not opposed to hard wiring the car charger into the boat's electrical system (although I'm open to hearing the best place to tap the power for that).

I'm certainly willing to buy a different 3.5mm cable to connect my dock or phone to the WS420SQ.

Thanks for the insight.
https://lh5.googleusercontent.com/-4neCkX13XLE/VO3ziUiOHrI/AAAAAAAAYEw/fO0o2U-petE/s800/20150225_074727.jpg

MLA
03-27-2015, 06:51 PM
Yesterday I was getting noise in my system again and the "solution" was to unplug the car charger (which was plugged into one of the boat's 12v cig lighter style sockets).

If the source thats power the dock and phone is different then that of the reset of the audio gear, its an invitation for noise.

BrettLee3232
03-27-2015, 06:54 PM
Get something like this...
http://www.amazon.com/PAC-SNI-1-3-5-3-5-mm-Isolator/dp/B001EAQTRI

trayson
03-27-2015, 06:59 PM
If the source thats power the dock and phone is different then that of the reset of the audio gear, its an invitation for noise.

I'm thinking it might be a good idea to hardwire the car charger and tie it into the same power as the rest of the audio gear...

trayson
03-27-2015, 07:00 PM
Get something like this...
http://www.amazon.com/PAC-SNI-1-3-5-3-5-mm-Isolator/dp/B001EAQTRI

I found one of those that's a ground loop isolator and a line driver in one. might give that a shot to also help with the output level of the phone vs. the rest of my system...

MLA
03-27-2015, 07:40 PM
GLI's are often times a bandaid that covers a fixable problem. The term "Ground Loop" is almost an oxymoron. Its difference in voltage potential that shows its ugly head on the ground side of the audio signal path and not really a ground problem.

I would also be cautious of a line driver on a head-phone AUX circuit. Doesnt take much voltage to induce noise.

David Analog
03-27-2015, 07:58 PM
Some guy on Wakeworld is experiencing the identical problem. You guys should get together and share your findings.

MLA
03-27-2015, 08:03 PM
yeah, especially since some know-it-all over there told him what to do :p

trayson
03-27-2015, 08:05 PM
Some guy on Wakeworld is experiencing the identical problem. You guys should get together and share your findings.

Yeah I think that guy is stalking me. But he sure has a bad ass boat.

David Analog
03-27-2015, 08:53 PM
Yeah I think that guy is stalking me. But he sure has a bad ass boat.

Well, at least there's some mutual admiration.

rcm022
03-27-2015, 09:15 PM
You can put a noise filter on the alternator... airplanes use this when they have similar issues.

rcm022
03-27-2015, 09:17 PM
Filter layout
21656

trayson
03-27-2015, 09:34 PM
Well, at least there's some mutual admiration.

Well, I am sure anyone here will attest to the fact that I am my biggest fan...

mmandley
03-27-2015, 11:54 PM
The reason you are getting the noise is because the Cig lighter is on the main Power Ground connect as the rest of your boat. So any noise in that portion of the system transmits to the stereo. This is the entire reason everyone says wire the Power/Ground on your stereo directly to the stereo battery and don't share any Boat commons to this.

I get a little noise when charging my cell on the boat as well. I generally will only run my charger if the boat is floating. No engine running means no noise for me.

Another thing I have found is some chargers create more noise then others. I use a 2 port charger and get less noise then the single port i have. I think this is just a luck of the draw between manufacturers.

Another issue I get is people who come out and get no cell service, or poor service cause noise in my towers, so I have them put there phones in Airplane mode.

I use AT&T so I have service on my lake, but at times you will here a buzz just before a text message comes in.

trayson
03-30-2015, 12:32 PM
Another issue I get is people who come out and get no cell service, or poor service cause noise in my towers, so I have them put there phones in Airplane mode.

I use AT&T so I have service on my lake, but at times you will here a buzz just before a text message comes in.

My understanding is that GSM phones are the ones that give that kind of noise. So if someone has T-Mobile, then you'd get that. Or maybe if someone had Verizon but had a dual band phone that was searching on GSM because they couldn't get a decent CDMA signal?

Most the time I'm riding in places with great coverage, so that's not much of an issue.