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View Full Version : Attn: Car Stereo Gurus! Need help with Ipod Line noise!



Andrew LB
03-30-2006, 08:29 PM
Ok fellas. A while back I had a great idea of mounting my Ipod dock connector inside my cars ashtray, which only fit properly after removing lots of material from the tray itself and then securing the dock using a little bead of the wonderful and almost indestructable JB-Weld.

http://www.kalionzes.com/evomods/_MG_8172.JPG
http://www.kalionzes.com/evomods/_MG_8173.JPG
http://www.kalionzes.com/evomods/_MG_8174.JPG

My problem is line noise.

When I have the ipod connected to my Clarion Pro Audio Deck using the Auxilary imputs on it... i get hissing ONLY when i have the power connector plugged into the dock or the ipod itself. This happens both when the ipod is muted or playing.

My first power source was hard wired into a constant 12v... and now that i've heard the noise.... i bought another car charger plug and plugged that into the cigarette lighter. The noise was the same both ways. I also tried it without the dock and got the same results. Car power + ipod = noise.

Now... if i unplug the ipod from power... i get ZERO noise regardless of the decks volume and it plays perfectly.

So i tested a few things. I changed RCA to 1/8" cables out. No luck.

I ran the ipod off AC power from the wall socket in my garage using the firewire/AC adapter and an extension cord, keeping the pod plugged into the dock as well as trying it with the dock. NO NOISE!!!

Running the Ipod off batteries while plugged into the deck also gave me NO NOISE!

So.... i took the ipod inside and plugged it into the AC outlet using the firewire adapter and plugged in my Sennheiser HD580 Audiophile grade headphones. NO NOISE! What was interesting though was when i plugged the ipod into both 12v sources i have (cig and hard wired) and I used my Sennheiser headphones, i got NO NOISE.

So.... i'm going nuts here. I've done TONS of car audio installations over the years and have never had an issue like this. Engine noise is usually the cause of a bad ground or running your RCA's next to your amplifiers power wire... but i grounded the radio inside the dash where i unscrewed a bolt a little and put the forked connector beneath it. I'm wondering if somehow the stereo decks ground is somehow interfering with things... but i don't see why considering i don't get noise using external power while plugged into the deck or when i use batteries.... or headphones.

Does anyone here have a suggestion to help me fix this problem?

I'd pull my hair out right now but i've got a buzz... anyone got some tweezers?? LoL!!

Thanks in advance everyone!

-Andrew


edit: Btw... having the engine on or off doesn't change things. The hard wired 12v is running off constant power. The Cig lighter is Aux 12v.

Andrew LB
03-31-2006, 12:38 AM
Anyone? I just switched grounds on the deck and nothing happened. I'm thinking about getting a noise filter for the 12v line to prevent any unwanted hiss...

Carlz0r
04-04-2006, 09:15 PM
Tried one of These (http://www.londondrugs.com/Cultures/en-US/Product+Detail/Electronics.htm?CatalogNavigationBreadCrumbs=Elect ronics;Electronics;Car%20Audio;Car%20Audio%20Acces sories;Pyramid%20Audio%20NS10%20-%20noise%20suppressor&CS_Catalog=Electronics&CS_RootCategory=Electronics&CS_Category=Car%20Audio%20Accessories&CS_ProductID=5017173&ProductTab=1)? If it doesn't work, it's only a couple of dollars out of your pocket. (The site is just a reference, I know you don't have london drugs in America)

Rippthrough
04-05-2006, 04:11 AM
Could quite easily be noise from the car systems on the 12v line, try a couple of capacitors to smooth out the line.

Slayer2k3
04-05-2006, 07:51 AM
Go to any car audio shop and ask for a line supressor. Tell em you want one for the tweeters to keep the bass out, not for the subs to keep the highs out.

What did you tap into for power, directly off the cig plug?

bullet2urbrain
04-05-2006, 10:50 AM
just curious, i just skimmed the description, do you get noise when the car is on? or all the time? is the "amount" of noise dependant on engine RPMs?

just to further isolate the problem.

ESPEE
05-07-2007, 02:16 PM
I'm getting the same thing. I had my ipod connected with through a DLO TransPod line-out into the line-in on my G35. I have also tried the headphone jack. I tried a sheilded cable, it didn't help at all. The problem seems slightly less when I use a cable that supports video and sound.

If my iPod is plugged into the DLO dock and charging I get line noise that's pitch is consistant with engine RPMs. If I take the iPod out of the dock, the line noise goes away.

Does anyone have expirence with iPod chargers that don't have this problem or know of an in-line cigarette noise filter?

I have a call into DLO because I'd love to get their new TransDock, but their engineers haven't responded...

bullet2urbrain
05-07-2007, 06:31 PM
I'm getting the same thing. I had my ipod connected with through a DLO TransPod line-out into the line-in on my G35. I have also tried the headphone jack. I tried a sheilded cable, it didn't help at all. The problem seems slightly less when I use a cable that supports video and sound.

If my iPod is plugged into the DLO dock and charging I get line noise that's pitch is consistant with engine RPMs. If I take the iPod out of the dock, the line noise goes away.

Does anyone have expirence with iPod chargers that don't have this problem or know of an in-line cigarette noise filter?

I have a call into DLO because I'd love to get their new TransDock, but their engineers haven't responded...

if engine RPM's vary the pitch of the noise it is Alternator whine/Engine noise, basically your car isnt grounded " well" you can check the resistance of the "chassis" with an OhmMeter/DMM and see what you get..

have you tried running just a 3.5mm cable from iPod to car? see whatcha get.

Cheers :toast:

[XC] leviathan18
05-07-2007, 07:02 PM
if engine RPM's vary the pitch of the noise it is Alternator whine/Engine noise, basically your car isnt grounded " well" you can check the resistance of the "chassis" with an OhmMeter/DMM and see what you get..

have you tried running just a 3.5mm cable from iPod to car? see whatcha get.

Cheers :toast:

what he said if the noise volume change with engine rpm isnt well grounded, try a direct cable to the battery terminal and a well grounded cable to the chasis if that doesnt help use a supresor line

ziddey
05-12-2007, 12:45 AM
Hopefully it works out for you. I can't speak about the noise, but I had also mounted my dock in my car. And "coincidentally" I've had 3 hard drive failures in one year

STEvil
05-12-2007, 01:04 AM
Need to filter input power to the ipod. Some caps/supressors should do it.

speed bump
05-13-2007, 02:49 PM
Your are getting a nice ground loop.

The line out should be grounded so that doesn't happen(well atleast on my Cowon it is).

Noob-ftw
05-13-2007, 03:48 PM
Try turning down the volume on the ipod and turning up your speaker volume of the car.