rancur3p1c

Do you guys get an electrical whine depending on vehicle speed and engine RPM?

I get this when plugged into the Aux WHEN my phone is charging.
Or, with the Bluetooth receiver to Aux-In. The cigarette adapter is grounded to the car electrical system and passes the electrical interference.

62Fender

You might try tapping a shielded circuit like the stop light switch circuit. The green wire on the harness is +12v w/ ignition on.

Another option might be a noise filter added to the aux circuit.

12V Car Power Supply Filter Auto Power Supply Remove Noise Filter | eBay

rancur3p1c

does that go in line with the aux headphone signal like a ground loop isolator? Those attenuate audio fidelity too, sounded terrible.


if it's for the power signal, I suppose it couldn't hurt and it's pretty cheap. although I made my own passive filter to no effect

rancur3p1c

also, do you remember if the head unit is grounded directly to the vehicle chassis as you bolt it in? or is it through one of the wires?


Grouding the head unit directly to the body frame + doing the same with the ground on the 12v cigarette lighter might help me, too

62Fender

I was thinking for the aux power wire but it sounds like you already tried it. Now I'm wondering if it would work as a ground wire filter?

Looks like the head is grounded from pin #7 of the head's A connector to "IG" ground. IG stands for "Instrument Panel Brace LH". The ground wire is brown. I can't tell whether the head also grounds directly to the dash mount.

Good luck with the fix.

kteddy

Hey there, I have the same exact problem. So here's what I do to reduce the noise, turn off the equalizer or put it on anything other than feel as that one seems to be the loudest, I notice its worse with my iphone and other devices where the charge port is directly next to the aux jack on the phone, charge cases like mophie and belkin will not make the noise if you charge through them while listening to music. As for a actual solution, I haven't found one yet.

TJenner2

In electronics we use what is known as a Ferroresonance (Ferrite) bead to trap electromagnetic fields generated by other devices. You might try something like what is pictured above. Use it like above, creating a few loops around the charging cable.

rancur3p1c

chokes typically operate in the 1MHz+ frequency range, well above the 20KHz range that the speakers produce and our ears hear.

I also tried designing and building my own power filter. I'm an electrical engineer. I'm not sure why it didn't work. I must be a bad engineer.


I actually bought this and as picky as I am about sound I honestly can't tell a difference in sound quality:


I'm happy with it. It doesn't even dampen the volume level as much as I was expecting. Don't buy the Radio Shack one, it sounds terrible, I returned it.

rancur3p1c

I'm probably going to look into this solution as well. Thanks for the thoughts.

Tshock

iTrader: (2)

I would imagine an IG ground would help. IG = Isolated Ground. Have you tried re-grounding the 12V power supplies?

rancur3p1c

this unit solved my problems without degrading signal clarity/audio fidelity.


It, however, is poorly constructed, so I recommend using hot glue to secure the cables as they come out of the chassis, to the enclosure, so that they don't have space to wiggle, which causes the wires to break loose inside the enclosure, causing one or both channels to either significantly attenuate or cut out all together.


My first one, in the process of use, made popping noises so loud, that it blew my passenger speaker. I'm currently trying to get PAC to replace my speaker.

rancur3p1c

they come directly from the alternator...?