Induced noise/Ground loop trouble shooting guide. - Page 6

nguyenpd · 08-13-2006, 11:19 AM

i have a ground loop isolator on each of my RCA going to my amp and i still have the damn high pitch sound. Could this be a bad ground from my HU or my amp?

When i had my amp hooked up the factory radio...i didnt have this problem at all.

RedGTiVR6 · 08-13-2006, 07:34 PM

Quote: Originally Posted by Moridin

Can you explain your opinion? I know it's no where close to competition level hardware so what makes it so bad?

To clarify my first statement:

My wife has a brand new 60GB ipod video and when I compare it to my creative...its night and day. whether it's using headphones or Home entertainement center, office stereo or even the Boss which is supposed to be "NOT good". That's only sound quality. Image quality is exactly the same story only when plugged to the tv mind you. I don't have the kinds of systems you guys do in my car.

what we have and what you have is not of any concern. What my comment was referring to is that the Boss products are not very high quality products. To say that something is better than something else when hooked up to a Boss product, doesn't hold much ground.

If it works great for you, go for it.

Wiredwrx · 08-13-2006, 10:12 PM

Quote: Originally Posted by Red GTi VR6

what we have and what you have is not of any concern. What my comment was referring to is that the Boss products are not very high quality products. To say that something is better than something else when hooked up to a Boss product, doesn't hold much ground.

If it works great for you, go for it.

Just cause I am now confused, are we talking about "BOSS" or "BOSE", and if we are talking about BOSE, how can anyone trust either of you, if you can't even spell the product name

Either way, while RED knows a bunch about car audio, if you enjoy the Bose, then enjoy the bose. RED is on a different level, with Berylium subs, Gold Amps, Titanium wiring, etc.... meaning she has an opinion about what she thinks is the best, and she gets the best. You and I will probably be very happy with Bose cause we are blissfully unaware. I like it like that.

I have been through this same thing when I started modding my WRX, I thought, nah, it's fast enough, then I got a taste of modding when I company I worked with offered me a free Cold Air Intake, and while I later found out CAIs aren't as great as I then thought, it lead me on a crazy journey modding, then remodding, and then remodding my car, everytime getting better and better stuff, till one day, the only thinkg stock in the power train was the engine block, everything else was modded. Sure, when people got a CAI, I was like, Heck, that stuff is crap, go big or go home, but you know what, for that guy, at that point, the CAI was good enough for him.

Just understand where RED is coming from.

NOW, back to the thread at hand,

Will, I know the GLI is a bandaid, but since the bandaid makes the booboo oh so much better, I will live with it. Maybe one day when sound quality makes a significant difference to me, I will get a better HU and Soundcard,but for now, I am fine.

Michael

RedGTiVR6 · 08-14-2006, 07:29 AM

Quote: Originally Posted by Wiredwrx

Just cause I am now confused, are we talking about "BOSS" or "BOSE", and if we are talking about BOSE, how can anyone trust either of you, if you can't even spell the product name

Who ever said anything about bose?

I just searched this thread for the word BOSE, and you're the only one that said anything about BOSE.

BOSS is the brand that we are speaking of here.

Quote:

Either way, while RED knows a bunch about car audio, if you enjoy the Bose, then enjoy the bose.

Perhaps you missed where I told the user that if it works for him go for it? However, you can't use a BOSS HU to compare anything as it's not a very good base (yes, BASE, not BASS, or BOSS, or BOSE) to go off of.

Quote:

You and I will probably be very happy with Bose cause we are blissfully unaware. I like it like that.

Again, you're the only one talking about BOSE, and no, BOSE doesn't make a HU for the car environment.

Using a BOSS HU to compare sound quality of two mp3 players, is like using a 7" black and white screen to compare the differences between two different HD TV signals. It's pointless.

What the guy wants to use in his ride is his prerogative, however, using it as a comparison has absolutely no grounds.

Nate Sickler · 08-21-2006, 02:07 PM

Help with audio noise.

Using 300 watt inverter (10 gauge wire from battery terminals).
Using an FM modulator and factory HU
CarPC interfaced with vga Touchscreen monitor. Monitor is powered through cigarette plug and carPC is powered through inverter.

I hear the altenator whine, but the sound pretty much disappears when the touchscreen is turned off. Not sure on how to ground a touchscreen. Could I run 10 gauge or thicker wire from the computer case to a piece of unpainted metal?

TIA

Antaeus · 09-01-2006, 09:40 PM

Thanks for the tip. I was also experiencing noise, a ground loop isolator did the trick. I'm just posting my configuration here, in case someone else has the same problem.

1) Laptop powered by an OEM laptop car charger (cigarette lighter).
2) Headphone jack to RCA y-cable. {fix: insert ground loop isolator here}
3) RCA FM modulator connected to the antenna of the factory car stereo.

Without the ground loop isolator there was a high-pitched whine and a pulsating static sound. This only occured when the laptop was connected to the charger, there was no problem when running off the battery.

chippyhawkeye · 09-11-2006, 05:30 PM

I tinkered and grounded till I was about to go nuts... I got everything much quieter, but the noises wouldn't go away. Most of my noise seemed to come from my computer, I could hear hard drives spinning up, fans spinning up, clicking from the hard drives over the speakers...

I used on board sound with an EPIA EN15000 -

Bought the ground loop isolator someone suggested and it is perfect now. I even removed all the extra ground wires I had connected first and still perfect..

So if your time is more valuable than the$20 for the Ground loop isolator, which I am sure you could return if it doesn't work, start there...

Just my opinion and experience...

S11D336B · 09-11-2006, 05:54 PM

Also, I think you'll find that a better sound card would fix the problem and be a better way to spend your money. A Sound Blaster Live would work nicely

rumy · 10-04-2006, 11:47 AM

Hi,
I have read this forum and done a lot of searching still have not been able to solve my problem. Any help is appreciated,

I am using a laptop, when on battery and on power I have no noise at all. As soon as I unmute the line in hte noise comes.

I want to use XM so need the line in and want to get rid of the noise.

I have tried external soundcards and still same issue. any suggestions other than DAC?

Thanks

Will Albers · 10-04-2006, 02:54 PM

Quote: Originally Posted by rumy

Hi,
I have read this forum and done a lot of searching still have not been able to solve my problem. Any help is appreciated,

I am using a laptop, when on battery and on power I have no noise at all. As soon as I unmute the line in hte noise comes.

I want to use XM so need the line in and want to get rid of the noise.

I have tried external soundcards and still same issue. any suggestions other than DAC?

Thanks

You have a ground loop between the XM and the Laptop. How are you powering the XM? How are you powering the laptop? I would recommend searching for USB soundcard noise problems. I would bet its the same type of thing.

Shad0wca7 · 10-04-2006, 05:34 PM

Ok here is the info:

J7F2 powered by M2-ATX powered direct from battery, grounded to cigarette lighter. Using onboard audio to a JVC head unit.

There was tons of noise (whirring etc + alternator whine) at first so I got a GLI hoping it would cure things.. well the whirring etc has gone away but the GLI seems to have taken away all bass (bad GLI?) and the alternator whine is still there..

The interesting thing about it is that it will totally disappear for a while and then come back.. randomly, I have not been able to link it to any particular action/cause. This happened before the GLI install as well.

Anybody have any suggestions?

rumy · 10-05-2006, 12:10 PM

Quote: Originally Posted by Will Albers

You have a ground loop between the XM and the Laptop. How are you powering the XM? How are you powering the laptop? I would recommend searching for USB soundcard noise problems. I would bet its the same type of thing.

I havent had any luck trying to find this, All I found is grounding issues and alternator whining, some posts people did mention to just mute the line in to get rid of noise, but I want to use the line in.

The XM is powered from my stock amp which goes straight to the battery. Also when I connect the XM directly into the amp there is no noise, its a clean signal.

Thanks

llajumpvid · 10-05-2006, 12:17 PM

Quote: Originally Posted by rumy

I havent had any luck trying to find this, All I found is grounding issues and alternator whining, some posts people did mention to just mute the line in to get rid of noise, but I want to use the line in.

The XM is powered from my stock amp which goes straight to the battery. Also when I connect the XM directly into the amp there is no noise, its a clean signal.

Thanks

What XM receiver are you using? I had the same problem using the XMD. I got rid of it when I grounded the case of the XMD.

RedGTiVR6 · 10-05-2006, 01:07 PM

can you explain how you are powering the XM off of the signal from the amplifier?

are you using a speaker level signal to power it? or are you tapping into the power BEFORE the amplifier?

WinoOutWest · 10-05-2006, 01:45 PM

First off thanks for a great article! I've eliminated almost all my noise and ground loops thanks to the original posts. I eliminated my really irritating alternator whining and uncovered/resolved 2 issues: I had to re-run the signal lines on the other side of the car and to ground the PC Case and the Inverter. I have one remaining noice and I am wondering what my options are to get rid of this noise and if changing the inverter will help.

The noise seems to be generated from DC-AC Inverter and I can't seem to get rid of it. I have the inverter mounted beside the PC which is also right beside the battery in the trunk as are the 2 Alpine V12 Amplifiers (a 4 channel driving front and rear speakers and a mono driving the sub). My head unit is an Alpine as well with now amplifiers on board just a 4v outs and the Aux line in from my PC. The noise is not present when I am using the radio or the CD on the Alpine. As soon as I switch it to the AUX I get the noise. If I run the PC directly from an AC line from the house I do not have the noise. I tried a ground loop isolator on the Line out from the PC and it seemed to make no difference. I have an Audigy 2 internal card as well as a Maya external USB sound card and it doesn't seem to make any difference in the noise.

Currently I have the inverter, inverter case and the PC case grounded directly to the battery.

I am beginning to suspect that its just a crappy inverter? Curious is I have any options. Do I need a better inverter or do I need to replace my inverter and shutdown controller with a DC supply?
Cheers!