Unoffical empeg BBS

Quick Links: Empeg FAQ | RioCar.Org | Hijack | BigDisk Builder | jEmplode | emphatic
Repairs: Repairs

Topic Options
#202127 - 03/02/2004 08:56 Multiple instances of ground loop problems
edsmiata
addict

Registered: 18/08/2002
Posts: 544
Loc: New Jersey
Maybe its because this BBS is dedicated to the Empeg only, but it seems like ground loop issues occur over and over. In the past I have had numerous systems installed in various cars and never once had an engine noise problem. Now granted they were pretty much plug and play without all of the wiring the sled of the Empeg has, but I wonder if it is the structure of the Empeg (essentially a microprocessor) that makes it more sensitive to this problem.

As you all well know I am plagued by this problem, and no matter how many times i 'fix' it it finds a way of reoccuring!

Any thoughts,


Ed
_________________________
...One man gathers what another man spills

Top
#202128 - 03/02/2004 09:22 Re: Multiple instances of ground loop problems [Re: edsmiata]
wfaulk
carpal tunnel

Registered: 25/12/2000
Posts: 16706
Loc: Raleigh, NC US
Multiple people, myself included, have had ground loop problems resolved by installing a new amplifier. Have you tried that? I know that it's not necessarily a cheap proposition, especially as a guess, but maybe you can find a friend who has an amp you can borrow for a few hours.
_________________________
Bitt Faulk

Top
#202129 - 03/02/2004 09:29 Re: Multiple instances of ground loop problems [Re: wfaulk]
edsmiata
addict

Registered: 18/08/2002
Posts: 544
Loc: New Jersey
As readers of my posts have noted in the past..i have a Sony HU along with the Empeg...when I take the Empeg out of the picture and hook the Sony directly up to the amps there is no noise...hook up the Empeg...Noise!

This is my observation...the Empeg is more susceptable to ground loop problems that traditional head units....

_________________________
...One man gathers what another man spills

Top
#202130 - 03/02/2004 09:41 Re: Multiple instances of ground loop problems [Re: edsmiata]
belezeebub
addict

Registered: 11/01/2001
Posts: 579
Ground loops are cause my voltage differances,
you can get what people call a "Group loop" if all the inputs on a multi-amp system are not balanced or if you are grounding amps or other devices at different points,

I had a ground loop with my system simplly re-adjusting all the inputs fixed it. when I removed my empeg and put in my alpine the ground loop was 3 times as bad (Readjusted and regrounded ground loop went away)

_________________________
______________________________________ Do not meddle in the affairs of Network Administrators, for they are subtle and quick to anger. ______________________________________ Worlds Lamest Wb Site (mine) http://home.comcast.net/~jlipchitz/

Top
#202131 - 03/02/2004 10:00 Re: Multiple instances of ground loop problems [Re: edsmiata]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14482
Loc: Canada
That's because the empeg has floating grounds on the audio lines. This can be converted to be similar to a "normal" HU by simply grounding the audio grounds to the empeg sled.

I haven't done a ton of installs, but my philosophy for grounds is to simply run a ground wire from every piece of equipment to a single point on the car chassis. And add extra grounds for the signal lines if needed, as per the comment above.

Cheers

Top
#202132 - 03/02/2004 11:51 Re: Multiple instances of ground loop problems [Re: mlord]
edsmiata
addict

Registered: 18/08/2002
Posts: 544
Loc: New Jersey
I have heard this term 'floating ground' many time here and still i dont understand the concept....how is the ground 'floating' and how would one convert it to a 'normal' ground
_________________________
...One man gathers what another man spills

Top
#202133 - 03/02/2004 12:05 Re: Multiple instances of ground loop problems [Re: edsmiata]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31571
Loc: Seattle, WA
In the past I have had numerous systems installed in various cars and never once had an engine noise problem.
Did they all have separate amplifiers?

I've always had to troubleshoot ground loop problems when I installed a CD player with a separate amplifier. The empeg was no different.

If all your other systems were just a head unit with speaker wire outputs, then of course you're not going to get a ground loop because there's nothing to "loop".

There's nothing inherently special about the Mark2 that makes it worse than a CD player in this regard. The Mark1 was the unit with the floating ground output, and it's the one that was a ground loop magnet. But the Mark2 is no different from a CD player with a separate amplifier unless there's a defect such as a loose wire.
_________________________
Tony Fabris

Top
#202134 - 03/02/2004 12:41 Re: Multiple instances of ground loop problems [Re: tfabris]
loren
carpal tunnel

Registered: 23/08/2000
Posts: 3826
Loc: SLC, UT, USA
Just a little side story... Ryan (co-worker with empeg) and i went over to Rolling Thunder the other day to get a quote on installing his empeg in his new S2000. Rolling Thunder is supposedly one of the best installers in the country, they've got plenty of awards to show for it, and everytime you go by there you are sure to see at least one +100,000 dollar car sitting in an install bay... not to mention the prices they charge. Anyhow, once the guy realized what an empeg was, he shook his head and asked if Ryan had had any noise problems with his previous install, to which Ryan said yes. Before Ryan could finish his sentence that we knew why there was noise due to problems with his install in his Explorer, the install guy said something to the effect of "yeah, i've installed 3 of them things and all of them were really noisy. Those things are just not well made or something". To which i jumped in and said that i'd installed mine in 3 cars, all noise free, as had hundreds of other people.

Just makes you wonder how an installer that would charge $2200 for a pair of MB Quarts and a JL amp with labor included could not properly ground an empeg.

We walked out laughing because we'll do the same install for around $700.
_________________________
|| loren ||

Top
#202135 - 03/02/2004 13:00 Re: Multiple instances of ground loop problems [Re: loren]
edsmiata
addict

Registered: 18/08/2002
Posts: 544
Loc: New Jersey
also makes you wonder who would actually PAY $2,200 for a pair of MB Quarts and a JL Amp..labor included!!!!!
_________________________
...One man gathers what another man spills

Top
#202136 - 03/02/2004 13:05 Re: Multiple instances of ground loop problems [Re: loren]
Roger
carpal tunnel

Registered: 18/01/2000
Posts: 5681
Loc: London, UK
Just makes you wonder how an installer ... could not properly ground an empeg.

Cambscar don't seem to have any problems installing empegs without ground loops. They've done both of my installs, and I'm sure they've done plenty of others.

Methinks that this Rolling Thunder place is perhaps a little overrated.
_________________________
-- roger

Top
#202137 - 03/02/2004 13:47 Re: Multiple instances of ground loop problems [Re: edsmiata]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14482
Loc: Canada
In this case, I used "floating ground" to refer to the "ground wire" portion of the audio signal cables -- when the outer sheath of the cables (or their connections within the player) are not connected to chassis ground (the car's frame, or the empeg's shell), then those are refered to as "floating".

Cheers

Top
#202138 - 03/02/2004 17:53 Re: Multiple instances of ground loop problems [Re: edsmiata]
tracerbullet
addict

Registered: 08/01/2002
Posts: 419
Loc: Minnesota
Maybe the empeg is fine and your Miata sucks in this regard?

I'll suggest it again - unbolt, unhook, "unwire" every stereo part in your car and lay it out - the empeg on the dash, any amps etc. on the seat. Run temporary wires between them all. Don't re-use a single piece that's in the car at the moment. The car will look like you dumped spaghetti inside, but so be it. At this point, with all wires out in the open, use only the battery post for power (and a switch for turn-on) and ground. I'd be 99.9% sure you'll have no noise problems. If you do, you know a piece of equipment is faulty, otherwise you'll know it's the wiring job. Then put it back, wire by wire, replacing the temporary leads with what is installed already in the car. One of them will bring back the noise and you'll know what to work on.

I'm sure it's something simple - a signal wire too close to the heater blower motor, something grounded to a piece of metal which in turn isn't grounded to anything else, whatever it might be. You've worked on it so long that you're overlooking the problem, thinking some part of the installation is good, when in fact it is not.

I dunno, you've talked about it for ages, I can't believe you haven't just ripped it all out and started over.

Top
#202139 - 03/02/2004 18:15 Re: Multiple instances of ground loop problems [Re: tracerbullet]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31571
Loc: Seattle, WA
From his description that he can press on the face of the player and get it to go away, I'd think of a loose connection somewhere either within the player, at the docking connector, or similar.
_________________________
Tony Fabris

Top
#202140 - 03/02/2004 18:20 Re: Multiple instances of ground loop problems [Re: tfabris]
pgrzelak
carpal tunnel

Registered: 15/08/2000
Posts: 4859
Loc: New Jersey, USA
I think the player is fine. I visited him, and we tried swapping players. Granted, there was no whine on that particular day (Murphy's Law), but there was no sign of anything amiss with the player itself that I could see.
_________________________
Paul Grzelak
200GB with 48MB RAM, Illuminated Buttons and Digital Outputs

Top
#202141 - 03/02/2004 19:15 Re: Multiple instances of ground loop problems [Re: edsmiata]
tanstaafl.
carpal tunnel

Registered: 08/07/1999
Posts: 5539
Loc: Ajijic, Mexico
and no matter how many times i 'fix' it it finds a way of reoccuring!

Any thoughts,


Y'know what I'd do? I'd find a small stereo shop, one where the owner of the shop does the actual nuts and bolts work and has some pride in what he does.

I'd give him $100, and say "Fix it. And if it doesn't stay fixed, I'll just keep coming back and make you do it again until it either stays fixed or you give up in despair and refund my money."

I bet you can find a shop or two willing to take up the challenge on those terms.

tanstaafl.

_________________________
"There Ain't No Such Thing As A Free Lunch"

Top
#202142 - 04/02/2004 07:36 Re: Multiple instances of ground loop problems [Re: tracerbullet]
edsmiata
addict

Registered: 18/08/2002
Posts: 544
Loc: New Jersey
Tracer...Oh I have!!! and every time I do that the problem is solved until little by little it comes back. Paul G will validate that about a month ago the install was noise free..now the whine is more than a nusiance...i am thinking that because the area behind the dash is sooo tight and the ride of the car is soooo rough that the josteling around over time moves the wireing around to where the problem originates...

hopefully it will be warm enough this weekend to start all over again...makes for frustrating drives and busy Weekends...but with all of the other responsibilities i, and i am sure the rest of our members, must deal with...at the end of the day i am happy if this is my most worrisome!

Ed
_________________________
...One man gathers what another man spills

Top
#202143 - 04/02/2004 07:49 Re: Multiple instances of ground loop problems [Re: tanstaafl.]
edsmiata
addict

Registered: 18/08/2002
Posts: 544
Loc: New Jersey
Tanstaafl,

I have called some shops up and did exactly that...at the end of the day there is not enough $$$ in if for them to do the legwork!

Thanks for the idea though!
_________________________
...One man gathers what another man spills

Top