Paul C

I had a ground loop problem and alternator whine I fitted a ground loop isolator, which apart from making the music sound weak did cure the ground loop problem but i still had my whine. After lots of messing about with volt meters etc and a trip to my local audio shop I cured the problem (or rather they did). The guy took one look and said i bet its your amp so he got one of the shelve and tried it and low and behold all my noise has gone.

Jono

Some Pioneer head units have bad earths to the RCAs which causes a whine through the speakers.

A quick fix is to take some wire, strip it, wrap it around the RCAs and wedge it under a screw on the back of the head unit.

__________________
Australian TRX Forums: Pintara/Corsair/Stanza/Bluebird/Altima info

canopy

Hey all,
I found something on how to solve some ground loop issues: https://myeporia.eporia.com/resource...ote%201002.pdf

hope it helps...

cya

Ko_deZ

Hi. I'm new here, but I think i could contribute.

First, try running the stereo without any RCA attached. If there is still noise, the problem is grounding, or noise trough power cables to the amp. Then, get an USB soundcard, and use USB cable all the way to the amplifier (elmininating noise, as it then is transfered digitally), and us as short a cable as possible between the soundcard unit and the amp. That would stop most noise from beeing able to mess up the analog part, cause that's where it hurts.

-ko_dez-

smactek

One small additional note. Mainly focused in automotive sound systems. be sure none of the negative speaker leads are grounded to the chassis. This can easily be checked by disconnecting speaker leads one at a time at the amplifier. One grounded lead will cause all the speakers to buzz.

ErikArmbrust

A lot of times there might be sinusoidal EMI interference caused by an inverter that unshielded RCAs are run close to. DC power also causes EMI when it's not shielded. I guess, I'm saying that if you can't route power cables anywhere but next to RCAs, just get shielded RCAs.. which are more expensive, but it eliminates the need to separate cable routings. It increases sound quality and magnitude very well.

__________________
Finished carputer:
2000 Black Blazer
Construction/ finished/ before
;)

Ozzman

What if im not comfortable drilling into the body? What are some other good grounding points? currently I have my screen and headunit grounded to the same OEM Radio Harness ground. with A LOT of RCA cables running around it, and of course getting a fair amount of whine, a lot more when the laptop runs on battery instead of the inverter. It also comes and goes depending on where I am and how fast I am going (or maybe I'm turning the stereo up too high and cant hear it anymore.)

I have a 98 Honda accord if anyone has the same and can recommend some good ground points that dont involve drilling.

Ko_deZ

Where the belt or seats are fastened are usually good spots.

-Ko_deZ-

RedGTiVR6

where belts or seats are fastened are usually NOT good spots.

You are better served to create your own ground. This is because you need contact to BARE metal. Using the bolt holes of a seat is not a good idea for a few reasons.

The threads for the bolt hole are usually covered in paint and have a bunch of garbage in them. This will prevent you from getting a solid ground.

Usually when you ground to a seat bolt, you're on top of the carpet. As such, you're only relying on the contact with the bolt, which then makes contact through the threads only for a ground. This is not a solid ground, no matter how you look at it.

Drilling into the car in the right place will not devalue the car in the least. Do it in the trunk under some carpet and you'll be fine.

Don't be scared to drill a small hole in the car. It's a needless worry.

__________________

Ko_deZ

Yes, those ARE good spots. There are several reasons for it. There is NOT paint inside the threads. Having that would be plain stupid, as the strength of the threads would be very poor, as well as them being broken every time you fasten/unfasten them. You do know what happens to your cars paint if you scratch a key along its side, right?

You will have to connect the ground to the metal parts of the car, that is true. There are some parts of the car that are not supposed to come loose in event of a crash, most notable is the seatbelt, and the seats. These are fastened in places that does not give in, and I can assure you that none of those places are disconnected from the chassis by using paint. That goes against all common sense.

Usually, if one want a good ground-connection, one removes paint to reveal bare metal on both sides of a metal plate, and put a bolt trough it, holding the whire. In a car, you have dozens of those places. Also, the you don't use a nut, but threads that are welded to the metal of the car, meaning that ever bit of thread helps to give a good grounding connection.

If you are still uncertain of how good the grounding is in the bolt, connect a multimeter and measure the resistance from the cars battery negative to the bolt that holdt the seat(-belt). Compare that to bare metal that you find somewhere.

Drilling a hole in the wrong place can give you condensing problems, and revealing bare metal in places that is supposed to be painted will run you the risk of rusting. Maybe not a big problem everywhere, but a unnessesary risk. I know a couple of professional audio builders (some that has won national DB drag championships, and they allway use the seat-belt bolt for grounding. It does not come much better than that.

-Ko_deZ-

RedGTiVR6

I will disagree with you and with using a seat bolt as a grounding point....and we've won 2 world titles in Sound Quality....where the quality of the install is actually judged...unlike in DB drag or any SPL comp for that matter. I'd also like to note that our vehicle consistantly scores the highest in install in the DIVISION, not just our class. Getting a 99% perfect score at finals is not easily done, and is very rare to boot.

And yes, we are the installers.

The point of my post was this: consider where you are trying to ground. Relying on a ring terminal that's going to give you 1/8" of contact to that bolt on the interior sides of the terminal is NOT a good ground.

Sanding away the paint and using the same bolt (as long as IT also has the paint removed) IS ok. No matter how you look at it, over time, grit and grime gets into the threads, which lessens your continuity.

I'd also like to note that there's a reason that major chains make it a standard to NOT use those locations for grounding.

__________________

Ko_deZ

You have som experience in the field. That is good. Makes the discussion more intersting =)

I can partially agree with you on the seat-bolts. You should sand down the area first. That should go without saying really.
As to the belt fastening points, I see no reason to not use them. From an electrical point of view (i am an electronic engineer after all), given that you sand down the area, and don't use a painted bolt (which I cannot remember to have encountered in any of these two positions), should give you as solid a ground as you can get in a car without welding or soldering.

Given time, rust and corrotion(or whatever that stuff that piles up on you battery poles is called in english) can make the connection weaker, but on these places things should be fastened so thightly that the forces forcing the threads together should stop any grit and grime from getting between them.

I can se a couple of resons not to use them, seen from a major chains point of view. If they mess up, and the seat belt or seat loosens in a crash, then they would be in for a major lawsuit. So better keep your hands off them. As long as you use common sense, the belt and seat fastening points should do just fine for grounding.

I do see the problem with painted bolts. Does cars tend to use that now? I have never seen that in the mentioned places before.

Getting that world championship is a lot of work, and believe me, all due respect for that. I am a bit curious about the US definition of world champions though. It seems to me that most of these world champion titles are won without much outside competition. Some US sports also seem to do this, even though only US teams are part of the competitions. Is that just a misunderstanding from my part? I do realize that "outsiders" are allowed to compete, but give that US has less than 10% of the worlds population, are more than 50% of the competetors from outside USA? Some input from one who actually has competed in these competitions would be very interesting, if you don't mind =)
I know that European competitions usually allows outside competetors, but the titles are usually European Champion, or German Champion. It might seem a bit weird that a englishman can be German Champion, but it happens sometimes. After all, a world champion is also the champion of France, Germany, Greece, Italy, Russia, India and China.

-Ko_deZ-

HiJackZX1

From my experience, do not have long ground runs. The recommended run should be 6 feet and under. On my first install it was double that. The system not only suffered from engine whine, but also was very slow. On the new install the ground is only 7 inches. Also do not use cheap ground loop isolators, they will muffle your sound, especially ones from Radio Shack. I went with one from BEST BUY from a company called Install Edge. It promises to not muffle sound and add a 3db gain, and it does as advertised.

__________________
PLANNING [IIIIIIIIIIIII] DONE
ITEMS [IIIIIIIIIIIII] DONE
INSTALL [IIIIIIII---]
BUDGET [IIIIIIIIIIIIIIII]IIIIIIIIIIIIII

lor109

Hijackzx1,

Does your 08' eby701 cause any noise in your system? The reason I ask is my PC is perfectly silent until I turn on the EBY701. With it on there is a high pitched whine. It is definatly worse when first starting the monitor in the morning. Calms down after 10 minutes or so, but never goes completely away. I suppose it could be the close proximity of the Screen to the Motherboard which is also installed in the dash, but I didn't have this problem with my previous Lilli. Everything is grounded to one point with only about 12 inches of wire.

Any help would be most appreciated.

Nathaniel

HiJackZX1

I honestly dont know. I am in the process of completing the install, and i sure hope not, because I have 3 EBY701s in my install. None of the screens will be powered by the PC, but rather a relay connected directly to the 12v+ and ground lines, with the ACC 12v+ being the activation switch. I decided on this because i did not want to bogg down my system in an way. Also i did it this way since all screens have there own regulators and fuses. Oh gosh you have me so worried now. Also as a note, my PC is no were near the screens.

__________________
PLANNING [IIIIIIIIIIIII] DONE
ITEMS [IIIIIIIIIIIII] DONE
INSTALL [IIIIIIII---]
BUDGET [IIIIIIIIIIIIIIII]IIIIIIIIIIIIII