Could This Whine Be Caused By a Ground Loop?

[sustain]

Could This Whine Be Caused By a Ground Loop?

The link below is to an MP3 file lasting only a few seconds (158 kb).

http://www.zshare.net/audio/605114385f1fe180/

Thanks.

[MOSFET]

Geez dude, that was hard on my ears. I couldn't even tell WHAT the heck I
was hearing, it sounded like a loud roar. Whine? Huh? It seemed to be the
only sample there so I ASSUME I was listening to what you intended us to
hear but I could make out no "whine", unless you want to call that loud roar
a whine.

Frankly, it's easier to just tell you what a ground-loop will sound like and
you can make the determination yourself. A ground loop typically sounds
like a high pitch whine that comes over your system and the whine changes in
pitch along with the RPM's of your engine.

The changing in pitch along with the RPM's is really the tell-tale sign of a
ground loop problem and if your whine DOES NOT change in pitch to match the
RPM's then it is probably NOT a ground loop.

However, if it does, then you indeed have a ground loop problem. In a
nutshell, ground loops are caused by differences in negative voltage
potentials between the different components of your system. These
differences are nulled out over the RCA's that connect them together and is
where the noise comes from. The reason it changes with the car's RPM's is
because as the alternator produces more or less current, both the positive
AND the negative electrical potential of the car changes, in other words the
grounds get closer together and further away as RPM's change and the car's
entire electrical potentials change and this getting closer and farther away
is what causes the changing of pitch.

How do you get rid of alternator whine? Well, for me, the VERY BEST tried
and true method which I have employed for over 20 years is connecting ALL
the grounds of your system together (head-unit, amps, processors, ect.) with
large gauge cable, like 8 or 4 gauge. You can simply ADD this to your
existing ground cables (you don't need to rip out what you already have).
What you accomplish by doing this is assuring that all grounds see the exact
same negative potential and presto, no more ground loops.

Now in theory, you shouldn't have to do this as the car's chassis (what most
people use as their grounds) is so large (larger than any gauge of wire)
that ALL points on the chassis SHOULD have precisly the same negative
potential. And for many cars I've owned and worked on this has often been
the case. But, in practice, it is simply a fact that different spots on a
car's chassis do indeed hold differing negative potentials. It's not always
clear why (different thickness in metals, different alloys that conduct
electricity a little different, ect.). So, again, the best way to
absolutely fix the problem is connecting all the grounds together with large
gauge copper wire, and any residual differences in ground potential will
null themselves out over this large copper wire, rather than your very thin
RCA wire.

This has ALWAYS fixed any ground-loop problem with any car I have ever
worked on. It is, for me anyway, been a sure fire fix. If that sounds like
a little too much hassle, however, Radio Shack and others sell ground-loop
isolators that connect between the RCA's and I know those always work well
and, as far as I can tell, do not effect the sound quality. They sell for
around $20 I think and are a quick and easy fix.

Anyway, hope this helps.

MOSFET


"sustain" > wrote in message
...
> Could This Whine Be Caused By a Ground Loop?
>
> The link below is to an MP3 file lasting only a few seconds (158 kb).
>
> http://www.zshare.net/audio/605114385f1fe180/
>
> Thanks.

[sustain]

Excellent explanation. I will look for an automotive electrician
first, before going to a Ford dealer.
What about this discussion regarding stereo systems and electricals -
http://www.3.8mustang.com/forum/showthread.php?p=3993863

Says pretty much the same thing, but much harder to understand! :)
Thanks
Sustain


On May 27, 2:46*am, "MOSFET" > wrote:
> Geez dude, that was hard on my ears. *I couldn't even tell WHAT the heck I
> was hearing, it sounded like a loud roar. *Whine? *Huh? *It seemed to be the
> only sample there so I ASSUME I was listening to what you intended us to
> hear but I could make out no "whine", unless you want to call that loud roar
> a whine.
[snip]....
>
> This has ALWAYS fixed any ground-loop problem with any car I have ever
> worked on. *It is, for me anyway, been a sure fire fix. *If that sounds like
> a little too much hassle, however, Radio Shack and others sell ground-loop
> isolators that connect between the RCA's and I know those always work well
> and, as far as I can tell, do not effect the sound quality. *They sell for
> around $20 I think and are a quick and easy fix.
>
> Anyway, hope this helps.
>
> MOSFET
>
> "sustain" > wrote in message
>
> ...
>
> > Could This Whine Be Caused By a Ground Loop?
>
> > The link below is to an MP3 file lasting only a few seconds (158 kb).
>
> >http://www.zshare.net/audio/605114385f1fe180/
>
> > Thanks.

[MOSFET]

Yes, a common response to ground loops is to try different spots on a car's
chassis for your grounding point or to make sure the spot you are using is
free of paint or primer, just bare metal. This can work many times because
as I stated before, in a perfect world, all points on a car's chassis would
have the same negative potential because the chassis is so large (again,
larger than ANY gauge of wire).

But experience has told me that different spots on many car's DO INDEED hold
differing negative electrical potentials. So you can become very frustrated
by trying spot after spot, sanding away to be sure you are touching bare
metals. Again, I suspect the answer to the riddle lies in differing alloys
that automotive manufactures use throughout the car and of course, every
alloy conducts electricity a little different. In the old days, of course,
when the entire chassis was made of one kind of steel, it was probably a
safer bet that you wouldn't have ground loop problems (as long as the metal
you were using was bare of paint or primer).

Grounding everything to the same spot is ESSENTIALLY the same advice I gave
but let me caution you about that. Grounding everything to the same spot is
actually, in truth, what you would see if you looked at my system (I use
four amps, an outboard X-over and a 6 band 1/2 DIN EQ along with my Alpine
HU and I am happy to say I have not a whisper of alternator whine in my 1999
Subaru Forrester), and although it is true everything is grounded to the
same spot, the KEY is that I use large gauge cable to ground everything to
this spot. That's why I gave you the advice I did. You see, if I had
simply told you to ground everything to the same spot you may have used 16
gauge wire over, perhaps, a 10 foot distance to ground, let's say, your HU.
The problem with this is that when dealing with low voltages, a relatively
thin wire like 16 gauge would have produced some internal resistance,
especially over a distance greater than a few feet. So grounding everything
to the same place is great advice with the caveat that you use large gauge
cable, AT LEAST 8 gauge, 4 gauge is better. Again, it help to remember what
we are trying to accomplish, we want all grounds to measure EXACTLY the same
negative potential. Electricity will travel through the path of least
resistance. We want to create a conduit that makes nulling these potentials
easy, hence large gauge copper cables, NOT very thin copper RCA cables. If
you were to use 16 or 18 gauge cable to ground your components (even low
current users like processors or EQ's) to a single point, you might STILL
find a difference in negative potentials and, again, some of this difference
might find it's way over the RCA's, which you DO NOT want. Using large
gauge cable ensures this does not happen. Also, again remember that it
isn't critical that all your grounds be at some SPECIFIC negative potential,
just that THEY ARE ALL EXACTLY THE SAME. So grounding them to the same spot
isn't as important as simply connecting them all together. That's why I
made the point that you don't necessarily have to move all your grounds to a
central spot (unless that would make things easier), but what's important is
that you ADD large gauge cable to all your grounds and have them all connect
together to null out any differences in neg. voltage potentials.

As far as ground-loop isolators, someone on that site said sometimes they
work and sometimes they don't. My experience is that as long as it is,
indeed, a ground loop you are dealing with, they will erradicate the problem
100% of the time. If they don't, then you don't have a ground loop to start
with. I'm not an EE so I can't tell you EXACTLY how they work, but they DO
stop that voltage leak that travels across the RCA's and do it in a way that
does not effect the sound quality in the least (at least not to my ears and
I have done extensive A/B testing with one once). Frankly, although it is a
band-aid solution which I tend to shy away from when it comes to
installation, they work so damn well it's tempting to just go that route as
opposed to tearing your whole electrical system apart and having to buy
20-30 feet of 4 guage cable. I have used those for a couple of friends cars
I did the install on and in every case, they worked magnificently. Although
my sure fire fix has always worked for my installs, I use pretty good gear.
I have encoutered over the years some low-quality processors or EQ's that I
simply was unable to remove the alternator whine despite all my tricks.
Their grounds were just integrated somehow with the RCA's and it was simply
impossible to completely erradicate a ground loop problem. For these types
of situations, the ground-loop isolators worked like a charm. So it's
definately something you might want to consider, you can always buy one and
if it doesn't work you can always return it, like I said they go for only
$20 at Radio Shack. But liek I said, if it is a ground-loop, an islolator
WILL get rid of the problem with no sonic differences. They are very cool
devices and for many of my friends, the best $20 they ever spent, even
though they are sort of band-aids.

See ya,
MOSFET

"sustain" > wrote in message
...
Excellent explanation. I will look for an automotive electrician
first, before going to a Ford dealer.
What about this discussion regarding stereo systems and electricals -
http://www.3.8mustang.com/forum/showthread.php?p=3993863

Says pretty much the same thing, but much harder to understand! :)
Thanks
Sustain


On May 27, 2:46 am, "MOSFET" > wrote:
> Geez dude, that was hard on my ears. I couldn't even tell WHAT the heck I
> was hearing, it sounded like a loud roar. Whine? Huh? It seemed to be the
> only sample there so I ASSUME I was listening to what you intended us to
> hear but I could make out no "whine", unless you want to call that loud
> roar
> a whine.
[snip]....
>
> This has ALWAYS fixed any ground-loop problem with any car I have ever
> worked on. It is, for me anyway, been a sure fire fix. If that sounds like
> a little too much hassle, however, Radio Shack and others sell ground-loop
> isolators that connect between the RCA's and I know those always work well
> and, as far as I can tell, do not effect the sound quality. They sell for
> around $20 I think and are a quick and easy fix.
>
> Anyway, hope this helps.
>
> MOSFET
>
> "sustain" > wrote in message
>
> ...
>
> > Could This Whine Be Caused By a Ground Loop?
>
> > The link below is to an MP3 file lasting only a few seconds (158 kb).
>
> >http://www.zshare.net/audio/605114385f1fe180/
>
> > Thanks.

[Mister.Lull]

I would agree with most of what MOSFET says, but I'll tell you my
experience(s) on the matter. Ground your amps with as short and as
big a wire as possible.

Once upon a time, I attempted to ground a single Class D Subwoofer amp
with a two foot length of 4 Gauge wire and the whine was unbelievably
loud and obnoxious. Simply by shortening that same wire (ground to
the same point on the chassis) by a foot (making it only 1 foot long),
the whine disappeared completely.

Currently, I have two amplifiers ground seperately, each with an 8-
inch length (or less) of 4 Gauge wire. There is no whine. In my
experience this is a simpler, less time-consuming solution for most
cases of alternator whine.

~Mister.Lull

On May 27, 1:07*pm, "MOSFET" > wrote:
> Yes, a common response to ground loops is to try different spots on a car's
> chassis for your grounding point or to make sure the spot you are using is
> free of paint or primer, just bare metal. *This can work many times because
> as I stated before, in a perfect world, all points on a car's chassis would
> have the same negative potential because the chassis is so large (again,
> larger than ANY gauge of wire).
>
> But experience has told me that different spots on many car's DO INDEED hold
> differing negative electrical potentials. *So you can become very frustrated
> by trying spot after spot, sanding away to be sure you are touching bare
> metals. *Again, I suspect the answer to the riddle lies in differing alloys
> that automotive manufactures use throughout the car and of course, every
> alloy conducts electricity a little different. *In the old days, of course,
> when the entire chassis was made of one kind of steel, it was probably a
> safer bet that you wouldn't have ground loop problems (as long as the metal
> you were using was bare of paint or primer).
>
> Grounding everything to the same spot is ESSENTIALLY the same advice I gave
> but let me caution you about that. *Grounding everything to the same spot is
> actually, in truth, what you would see if you looked at my system (I use
> four amps, an outboard X-over and a 6 band 1/2 DIN EQ along with my Alpine
> HU and I am happy to say I have not a whisper of alternator whine in my 1999
> Subaru Forrester), and although it is true everything is grounded to the
> same spot, the KEY is that I use large gauge cable to ground everything to
> this spot. *That's why I gave you the advice I did. *You see, if I had
> simply told you to ground everything to the same spot you may have used 16
> gauge wire over, perhaps, a 10 foot distance to ground, let's say, your HU.
> The problem with this is that when dealing with low voltages, a relatively
> thin wire like 16 gauge would have produced some internal resistance,
> especially over a distance greater than a few feet. *So grounding everything
> to the same place is great advice with the caveat that you use large gauge
> cable, AT LEAST 8 gauge, 4 gauge is better. *Again, it help to remember what
> we are trying to accomplish, we want all grounds to measure EXACTLY the same
> negative potential. *Electricity will travel through the path of least
> resistance. *We want to create a conduit that makes nulling these potentials
> easy, hence large gauge copper cables, NOT very thin copper RCA cables. *If
> you were to use 16 or 18 gauge cable to ground your components (even low
> current users like processors or EQ's) to a single point, you might STILL
> find a difference in negative potentials and, again, some of this difference
> might find it's way over the RCA's, which you DO NOT want. *Using large
> gauge cable ensures this does not happen. *Also, again remember that it
> isn't critical that all your grounds be at some SPECIFIC negative potential,
> just that THEY ARE ALL EXACTLY THE SAME. *So grounding them to the same spot
> isn't as important as simply connecting them all together. *That's why I
> made the point that you don't necessarily have to move all your grounds to a
> central spot (unless that would make things easier), but what's important is
> that you ADD large gauge cable to all your grounds and have them all connect
> together to null out any differences in neg. voltage potentials.
>
> As far as ground-loop isolators, someone on that site said sometimes they
> work and sometimes they don't. *My experience is that as long as it is,
> indeed, a ground loop you are dealing with, they will erradicate the problem
> 100% of the time. *If they don't, then you don't have a ground loop to start
> with. *I'm not an EE so I can't tell you EXACTLY how they work, but they DO
> stop that voltage leak that travels across the RCA's and do it in a way that
> does not effect the sound quality in the least (at least not to my ears and
> I have done extensive A/B testing with one once). *Frankly, although it is a
> band-aid solution which I tend to shy away from when it comes to
> installation, they work so damn well it's tempting to just go that route as
> opposed to tearing your whole electrical system apart and having to buy
> 20-30 feet of 4 guage cable. *I have used those for a couple of friends cars
> I did the install on and in every case, they worked magnificently. *Although
> my sure fire fix has always worked for my installs, I use pretty good gear.

[GregS[_3_]]

In article >, "Mister.Lull" > wrote:
>I would agree with most of what MOSFET says, but I'll tell you my
>experience(s) on the matter. Ground your amps with as short and as
>big a wire as possible.
>
>Once upon a time, I attempted to ground a single Class D Subwoofer amp
>with a two foot length of 4 Gauge wire and the whine was unbelievably
>loud and obnoxious. Simply by shortening that same wire (ground to
>the same point on the chassis) by a foot (making it only 1 foot long),
>the whine disappeared completely.
>
>Currently, I have two amplifiers ground seperately, each with an 8-
>inch length (or less) of 4 Gauge wire. There is no whine. In my
>experience this is a simpler, less time-consuming solution for most
>cases of alternator whine.
>
>~Mister.Lull
>

Its not just the DC resistance of the ground except for brute average force.
RF and audio interference has a radiated part which having various lengths
of wire can sort of resonate, radiate, and receive, noise.

If manufacturers would start to isolate the signal ground from chassis,
things may get easier, and also using differential signal distribution.
You CAN use transformers, but they have some limitations.
In not many instances did I ground through chassis, mostly because
of trying to find a good point to get to, drill into, or clamp to.
I do not trust any CRIMPED connection untill its soldered.

greg


>On May 27, 1:07=A0pm, "MOSFET" > wrote:
>> Yes, a common response to ground loops is to try different spots on a car=
>'s
>> chassis for your grounding point or to make sure the spot you are using i=
>s
>> free of paint or primer, just bare metal. =A0This can work many times bec=
>ause
>> as I stated before, in a perfect world, all points on a car's chassis wou=
>ld
>> have the same negative potential because the chassis is so large (again,
>> larger than ANY gauge of wire).
>>
>> But experience has told me that different spots on many car's DO INDEED h=
>old
>> differing negative electrical potentials. =A0So you can become very frust=
>rated
>> by trying spot after spot, sanding away to be sure you are touching bare
>> metals. =A0Again, I suspect the answer to the riddle lies in differing al=
>loys
>> that automotive manufactures use throughout the car and of course, every
>> alloy conducts electricity a little different. =A0In the old days, of cou=
>rse,
>> when the entire chassis was made of one kind of steel, it was probably a
>> safer bet that you wouldn't have ground loop problems (as long as the met=
>al
>> you were using was bare of paint or primer).
>>
>> Grounding everything to the same spot is ESSENTIALLY the same advice I ga=
>ve
>> but let me caution you about that. =A0Grounding everything to the same sp=
>ot is
>> actually, in truth, what you would see if you looked at my system (I use
>> four amps, an outboard X-over and a 6 band 1/2 DIN EQ along with my Alpin=
>e
>> HU and I am happy to say I have not a whisper of alternator whine in my 1=
>999
>> Subaru Forrester), and although it is true everything is grounded to the
>> same spot, the KEY is that I use large gauge cable to ground everything t=
>o
>> this spot. =A0That's why I gave you the advice I did. =A0You see, if I ha=
>d
>> simply told you to ground everything to the same spot you may have used 1=
>6
>> gauge wire over, perhaps, a 10 foot distance to ground, let's say, your H=
>U.
>> The problem with this is that when dealing with low voltages, a relativel=
>y
>> thin wire like 16 gauge would have produced some internal resistance,
>> especially over a distance greater than a few feet. =A0So grounding every=
>thing
>> to the same place is great advice with the caveat that you use large gaug=
>e
>> cable, AT LEAST 8 gauge, 4 gauge is better. =A0Again, it help to remember=
> what
>> we are trying to accomplish, we want all grounds to measure EXACTLY the s=
>ame
>> negative potential. =A0Electricity will travel through the path of least
>> resistance. =A0We want to create a conduit that makes nulling these poten=
>tials
>> easy, hence large gauge copper cables, NOT very thin copper RCA cables. =
>=A0If
>> you were to use 16 or 18 gauge cable to ground your components (even low
>> current users like processors or EQ's) to a single point, you might STILL
>> find a difference in negative potentials and, again, some of this differe=
>nce
>> might find it's way over the RCA's, which you DO NOT want. =A0Using large
>> gauge cable ensures this does not happen. =A0Also, again remember that it
>> isn't critical that all your grounds be at some SPECIFIC negative potenti=
>al,
>> just that THEY ARE ALL EXACTLY THE SAME. =A0So grounding them to the same=
> spot
>> isn't as important as simply connecting them all together. =A0That's why =
>I
>> made the point that you don't necessarily have to move all your grounds t=
>o a
>> central spot (unless that would make things easier), but what's important=
> is
>> that you ADD large gauge cable to all your grounds and have them all conn=
>ect
>> together to null out any differences in neg. voltage potentials.
>>
>> As far as ground-loop isolators, someone on that site said sometimes they
>> work and sometimes they don't. =A0My experience is that as long as it is,
>> indeed, a ground loop you are dealing with, they will erradicate the prob=
>lem
>> 100% of the time. =A0If they don't, then you don't have a ground loop to =
>start
>> with. =A0I'm not an EE so I can't tell you EXACTLY how they work, but the=
>y DO
>> stop that voltage leak that travels across the RCA's and do it in a way t=
>hat
>> does not effect the sound quality in the least (at least not to my ears a=
>nd
>> I have done extensive A/B testing with one once). =A0Frankly, although it=
> is a
>> band-aid solution which I tend to shy away from when it comes to
>> installation, they work so damn well it's tempting to just go that route =
>as
>> opposed to tearing your whole electrical system apart and having to buy
>> 20-30 feet of 4 guage cable. =A0I have used those for a couple of friends=
> cars
>> I did the install on and in every case, they worked magnificently. =A0Alt=
>hough
>> my sure fire fix has always worked for my installs, I use pretty good gea=
>r.
>> I have encoutered over the years some low-quality processors or EQ's that=
> I
>> simply was unable to remove the alternator whine despite all my tricks.
>> Their grounds were just integrated somehow with the RCA's and it was simp=
>ly
>> impossible to completely erradicate a ground loop problem. =A0For these t=
>ypes
>> of situations, the ground-loop isolators worked like a charm. =A0So it's
>> definately something you might want to consider, you can always buy one a=
>nd
>> if it doesn't work you can always return it, like I said they go for only
>> $20 at Radio Shack. =A0But liek I said, if it is a ground-loop, an islola=
>tor
>> WILL get rid of the problem with no sonic differences. =A0They are very c=
>ool
>> devices and for many of my friends, the best $20 they ever spent, even
>> though they are sort of band-aids.
>>
>> See ya,
>> MOSFET
>>
>> "sustain" > wrote in message
>>
>> ...
>> Excellent explanation. I will look for an automotive electrician
>> first, before going to a Ford dealer.
>> What about this discussion regarding stereo systems and electricals -http=
>://www.3.8mustang.com/forum/showthread.php?p=3D3993863
>>
>> Says pretty much the same thing, but much harder to understand! :)
>> Thanks
>> Sustain
>>
>> On May 27, 2:46 am, "MOSFET" > wrote:
>>
>>
>>
>> > Geez dude, that was hard on my ears. I couldn't even tell WHAT the heck=
> I
>> > was hearing, it sounded like a loud roar. Whine? Huh? It seemed to be t=
>he
>> > only sample there so I ASSUME I was listening to what you intended us t=
>o
>> > hear but I could make out no "whine", unless you want to call that loud
>> > roar
>> > a whine.
>> [snip]....
>>
>> > This has ALWAYS fixed any ground-loop problem with any car I have ever
>> > worked on. It is, for me anyway, been a sure fire fix. If that sounds l=
>ike
>> > a little too much hassle, however, Radio Shack and others sell ground-l=
>oop
>> > isolators that connect between the RCA's and I know those always work w=
>ell
>> > and, as far as I can tell, do not effect the sound quality. They sell f=
>or
>> > around $20 I think and are a quick and easy fix.
>>
>> > Anyway, hope this helps.
>>
>> > MOSFET
>>
>> > "sustain" > wrote in message
>>
>> ..=
>..
>>
>> > > Could This Whine Be Caused By a Ground Loop?
>>
>> > > The link below is to an MP3 file lasting only a few seconds (158 kb).
>>
>> > >http://www.zshare.net/audio/605114385f1fe180/
>>
>> > > Thanks.- Hide quoted text -
>>
>> - Show quoted text -
>

[MOSFET]

Yes, Lull and Greg, there is always some internal resistance with even very
large guage wire (especially when running a ton of current through it) and
Lull I certainly should have added to my advice KEEP WIRE LENGTHS AS SHORT
AS POSSILBLE. This is a key factor and I should have mentioned this.

I think I was centered on the notion that when dealing with a car that has
many differenent neg. potential values throughout the chassis, connecting
all the grounds together is the NEXT best thing you can do.

But if your car has pretty much uniform neg. potential values throught the
chassis, then of course the most important thing is to use as short a length
of ground cable (and as large) as you possibly can as you correctly point
out that even a one foot distance with four guage, if you are running a ton
of current through it, WILL make an internal resistance difference, which,
again, in a perfect world makes the car's chassis THE BEST ground return.

MOSFET

"GregS" > wrote in message
...
> In article
> >,
> "Mister.Lull" > wrote:
>>I would agree with most of what MOSFET says, but I'll tell you my
>>experience(s) on the matter. Ground your amps with as short and as
>>big a wire as possible.
>>
>>Once upon a time, I attempted to ground a single Class D Subwoofer amp
>>with a two foot length of 4 Gauge wire and the whine was unbelievably
>>loud and obnoxious. Simply by shortening that same wire (ground to
>>the same point on the chassis) by a foot (making it only 1 foot long),
>>the whine disappeared completely.
>>
>>Currently, I have two amplifiers ground seperately, each with an 8-
>>inch length (or less) of 4 Gauge wire. There is no whine. In my
>>experience this is a simpler, less time-consuming solution for most
>>cases of alternator whine.
>>
>>~Mister.Lull
>>
>
> Its not just the DC resistance of the ground except for brute average
> force.
> RF and audio interference has a radiated part which having various lengths
> of wire can sort of resonate, radiate, and receive, noise.
>
> If manufacturers would start to isolate the signal ground from chassis,
> things may get easier, and also using differential signal distribution.
> You CAN use transformers, but they have some limitations.
> In not many instances did I ground through chassis, mostly because
> of trying to find a good point to get to, drill into, or clamp to.
> I do not trust any CRIMPED connection untill its soldered.
>
> greg
>
>
>>On May 27, 1:07=A0pm, "MOSFET" > wrote:
>>> Yes, a common response to ground loops is to try different spots on a
>>> car=
>>'s
>>> chassis for your grounding point or to make sure the spot you are using
>>> i=
>>s
>>> free of paint or primer, just bare metal. =A0This can work many times
>>> bec=
>>ause
>>> as I stated before, in a perfect world, all points on a car's chassis
>>> wou=
>>ld
>>> have the same negative potential because the chassis is so large (again,
>>> larger than ANY gauge of wire).
>>>
>>> But experience has told me that different spots on many car's DO INDEED
>>> h=
>>old
>>> differing negative electrical potentials. =A0So you can become very
>>> frust=
>>rated
>>> by trying spot after spot, sanding away to be sure you are touching bare
>>> metals. =A0Again, I suspect the answer to the riddle lies in differing
>>> al=
>>loys
>>> that automotive manufactures use throughout the car and of course, every
>>> alloy conducts electricity a little different. =A0In the old days, of
>>> cou=
>>rse,
>>> when the entire chassis was made of one kind of steel, it was probably a
>>> safer bet that you wouldn't have ground loop problems (as long as the
>>> met=
>>al
>>> you were using was bare of paint or primer).
>>>
>>> Grounding everything to the same spot is ESSENTIALLY the same advice I
>>> ga=
>>ve
>>> but let me caution you about that. =A0Grounding everything to the same
>>> sp=
>>ot is
>>> actually, in truth, what you would see if you looked at my system (I use
>>> four amps, an outboard X-over and a 6 band 1/2 DIN EQ along with my
>>> Alpin=
>>e
>>> HU and I am happy to say I have not a whisper of alternator whine in my
>>> 1=
>>999
>>> Subaru Forrester), and although it is true everything is grounded to the
>>> same spot, the KEY is that I use large gauge cable to ground everything
>>> t=
>>o
>>> this spot. =A0That's why I gave you the advice I did. =A0You see, if I
>>> ha=
>>d
>>> simply told you to ground everything to the same spot you may have used
>>> 1=
>>6
>>> gauge wire over, perhaps, a 10 foot distance to ground, let's say, your
>>> H=
>>U.
>>> The problem with this is that when dealing with low voltages, a
>>> relativel=
>>y
>>> thin wire like 16 gauge would have produced some internal resistance,
>>> especially over a distance greater than a few feet. =A0So grounding
>>> every=
>>thing
>>> to the same place is great advice with the caveat that you use large
>>> gaug=
>>e
>>> cable, AT LEAST 8 gauge, 4 gauge is better. =A0Again, it help to
>>> remember=
>> what
>>> we are trying to accomplish, we want all grounds to measure EXACTLY the
>>> s=
>>ame
>>> negative potential. =A0Electricity will travel through the path of least
>>> resistance. =A0We want to create a conduit that makes nulling these
>>> poten=
>>tials
>>> easy, hence large gauge copper cables, NOT very thin copper RCA cables.
>>> =
>>=A0If
>>> you were to use 16 or 18 gauge cable to ground your components (even low
>>> current users like processors or EQ's) to a single point, you might
>>> STILL
>>> find a difference in negative potentials and, again, some of this
>>> differe=
>>nce
>>> might find it's way over the RCA's, which you DO NOT want. =A0Using
>>> large
>>> gauge cable ensures this does not happen. =A0Also, again remember that
>>> it
>>> isn't critical that all your grounds be at some SPECIFIC negative
>>> potenti=
>>al,
>>> just that THEY ARE ALL EXACTLY THE SAME. =A0So grounding them to the
>>> same=
>> spot
>>> isn't as important as simply connecting them all together. =A0That's why
>>> =
>>I
>>> made the point that you don't necessarily have to move all your grounds
>>> t=
>>o a
>>> central spot (unless that would make things easier), but what's
>>> important=
>> is
>>> that you ADD large gauge cable to all your grounds and have them all
>>> conn=
>>ect
>>> together to null out any differences in neg. voltage potentials.
>>>
>>> As far as ground-loop isolators, someone on that site said sometimes
>>> they
>>> work and sometimes they don't. =A0My experience is that as long as it
>>> is,
>>> indeed, a ground loop you are dealing with, they will erradicate the
>>> prob=
>>lem
>>> 100% of the time. =A0If they don't, then you don't have a ground loop to
>>> =
>>start
>>> with. =A0I'm not an EE so I can't tell you EXACTLY how they work, but
>>> the=
>>y DO
>>> stop that voltage leak that travels across the RCA's and do it in a way
>>> t=
>>hat
>>> does not effect the sound quality in the least (at least not to my ears
>>> a=
>>nd
>>> I have done extensive A/B testing with one once). =A0Frankly, although
>>> it=
>> is a
>>> band-aid solution which I tend to shy away from when it comes to
>>> installation, they work so damn well it's tempting to just go that route
>>> =
>>as
>>> opposed to tearing your whole electrical system apart and having to buy
>>> 20-30 feet of 4 guage cable. =A0I have used those for a couple of
>>> friends=
>> cars
>>> I did the install on and in every case, they worked magnificently.
>>> =A0Alt=
>>hough
>>> my sure fire fix has always worked for my installs, I use pretty good
>>> gea=
>>r.
>>> I have encoutered over the years some low-quality processors or EQ's
>>> that=
>> I
>>> simply was unable to remove the alternator whine despite all my tricks.
>>> Their grounds were just integrated somehow with the RCA's and it was
>>> simp=
>>ly
>>> impossible to completely erradicate a ground loop problem. =A0For these
>>> t=
>>ypes
>>> of situations, the ground-loop isolators worked like a charm. =A0So it's
>>> definately something you might want to consider, you can always buy one
>>> a=
>>nd
>>> if it doesn't work you can always return it, like I said they go for
>>> only
>>> $20 at Radio Shack. =A0But liek I said, if it is a ground-loop, an
>>> islola=
>>tor
>>> WILL get rid of the problem with no sonic differences. =A0They are very
>>> c=
>>ool
>>> devices and for many of my friends, the best $20 they ever spent, even
>>> though they are sort of band-aids.
>>>
>>> See ya,
>>> MOSFET
>>>
>>> "sustain" > wrote in message
>>>
>>> ...
>>> Excellent explanation. I will look for an automotive electrician
>>> first, before going to a Ford dealer.
>>> What about this discussion regarding stereo systems and
>>> electricals -http=
>>://www.3.8mustang.com/forum/showthread.php?p=3D3993863
>>>
>>> Says pretty much the same thing, but much harder to understand! :)
>>> Thanks
>>> Sustain
>>>
>>> On May 27, 2:46 am, "MOSFET" > wrote:
>>>
>>>
>>>
>>> > Geez dude, that was hard on my ears. I couldn't even tell WHAT the
>>> > heck=
>> I
>>> > was hearing, it sounded like a loud roar. Whine? Huh? It seemed to be
>>> > t=
>>he
>>> > only sample there so I ASSUME I was listening to what you intended us
>>> > t=
>>o
>>> > hear but I could make out no "whine", unless you want to call that
>>> > loud
>>> > roar
>>> > a whine.
>>> [snip]....
>>>
>>> > This has ALWAYS fixed any ground-loop problem with any car I have ever
>>> > worked on. It is, for me anyway, been a sure fire fix. If that sounds
>>> > l=
>>ike
>>> > a little too much hassle, however, Radio Shack and others sell
>>> > ground-l=
>>oop
>>> > isolators that connect between the RCA's and I know those always work
>>> > w=
>>ell
>>> > and, as far as I can tell, do not effect the sound quality. They sell
>>> > f=
>>or
>>> > around $20 I think and are a quick and easy fix.
>>>
>>> > Anyway, hope this helps.
>>>
>>> > MOSFET
>>>
>>> > "sustain" > wrote in message
>>>
>>> ..=
>>..
>>>
>>> > > Could This Whine Be Caused By a Ground Loop?
>>>
>>> > > The link below is to an MP3 file lasting only a few seconds (158
>>> > > kb).
>>>
>>> > >http://www.zshare.net/audio/605114385f1fe180/
>>>
>>> > > Thanks.- Hide quoted text -
>>>
>>> - Show quoted text -
>>

[MOSFET]

I didn't even touch on the subject of other types of noise like radiated
EMI (and all the strategies that can be employed when dealing with this type
of noise like seperating RCA's and power cables, ect.) as the original
thread dealt with ground loops.

MOSFET

[MOSFET]

Once upon a time, I attempted to ground a single Class D Subwoofer amp
with a two foot length of 4 Gauge wire and the whine was unbelievably
loud and obnoxious. Simply by shortening that same wire (ground to
the same point on the chassis) by a foot (making it only 1 foot long),
the whine disappeared completely.


You know Lull, I thought about this.

Remember, I'm still recovering from my heart operation so I have lots of
time to think about things ;).

And I can't think of a single time I ever had a ground loop issue that dealt
with the subwoofer amp, PROVIDED you, and me in past installs, were feeding
the subwoofer amp it's own output from the HU. The RCA outputs of a HU are
isolated in such a way that although you certainly COULD be experiencing a
ground loop via your subwoofer RCA's, I can't imagine you would HEAR such a
high-pitch whine over your subs?

So I'm assuming the ground loop noise was coming over your other speakers.
And again, I THOUGHT that those outputs were isolated in such a way that you
wouldn't hear such a ground loop unless your midrange amps were also
experiencing a ground loop problem.

Now maybe I'm way off on this issue, but let's suppose the curent draw of
your Class D amp was so great that although the loop was only through your
subwoofer RCA's, the difference in ground potential between the two
componets (HU and Class D amp) was sooooo great it effected ALL the RCA's as
the HU desperately tried to null out the difference. You see, the other
thing that intrigues me about your story is that at two feet you have this
huge ground loop problem, yet at one foot it apparently completely goes
away. Logically, that's a little hard to reconcile as you would EXPECT (if
your problem was caused by internal resistance due to this two foot length
of four guage) that by cutting the length in half, your problem should
logically be still there, but half as bad (as your ground differences should
now be half as severe as they were before). If the problem before was
HUGE, by cutting the voltage differential in half would it COMPLETLY go
away? Hmmmmm.....

Let me postulate something: I can't help but wonder if at two feet, your
ground loop was so severe, you crossed some threshold on your HU (sucking
current over your subwoofer RCA's) that made it impossible for it to isolate
the ground differences amongst the other RCA outputs. But at one foot,
whatever ground-loop that might still be present would be small enough to be
restricted to your subwoofer outputs only, and as ground-loops are typically
high-pitched, they would be inaudible on a subwoofer system, and presto,
your problem would APPEAR to completely go away. Simply stated, at two feet
your HU WAS OVERWHELMED, effecting all RCA's as it desperately tried to null
out what to it was an enormous difference. At one foot, the problem was
resricted to your subwoofer output only, as it should be, and therefore,
inauduble.

I know, I know, I don't have enough to do. That's what you're thinking
right now. I know it.

It was just intriguing that at two feet the problem was huge, and at one
foot it seemed to completely go away. That just seemed to not entirely
track for me and I was thinking of a reason why this might be so.

Again, I'm NOT challanging what you are saying, just approaching this as an
intellectual excercise. Feel free to elaborate if there are more details to
this story.

Take care Lull,

Nick

[Mister.Lull]

Oh Nick...

Now I'm going to throw a curve-ball your way.

When I say "once upon a time" this was probably 8-10 years ago, when I
was first getting in to this, um, sport (?). With the installation
I'm talking about, I was running 4 speakers right off the HU, and one
sub off of a class D amp.

Now, this doesn't change your overall theory, I suppose, just the
specifics.

First, I'll be honest, I don't remember if the whine was coming out of
the interior speakers - I DO remember the whine coming out of the
sub. 0_o The deck I was using didn't have a built in crossover, and
the amp said it was automatically crossed over at 300Hz (so I didn't
worry about it). But there was high pitched AND a low-pitched
undertone whine coming from the sub.

Weird, eh?

I always figured it was a difference in current between the power wire
and a long/poor ground (both were 4 gauge)...

~Mister.Lull

On May 29, 5:47*pm, "MOSFET" > wrote:
> Once upon a time, I attempted to ground a single Class D Subwoofer amp
> with a two foot length of 4 Gauge wire and the whine was unbelievably
> loud and obnoxious. *Simply by shortening that same wire (ground to
> the same point on the chassis) by a foot (making it only 1 foot long),
> the whine disappeared completely.
>
> You know Lull, I thought about this.
>
> Remember, I'm still recovering from my heart operation so I have lots of
> time to think about things ;).
>
> And I can't think of a single time I ever had a ground loop issue that dealt
> with the subwoofer amp, PROVIDED you, and me in past installs, were feeding
> the subwoofer amp it's own output from the HU. *The RCA outputs of a HU are
> isolated in such a way that although you certainly COULD be experiencing a
> ground loop via your subwoofer RCA's, I can't imagine you would HEAR such a
> high-pitch whine over your subs?
>
> So I'm assuming the ground loop noise was coming over your other speakers..
> And again, I THOUGHT that those outputs were isolated in such a way that you
> wouldn't hear such a ground loop unless your midrange amps were also
> experiencing a ground loop problem.
>
> Now maybe I'm way off on this issue, but let's suppose the curent draw of
> your Class D amp was so great that although the loop was only through your
> subwoofer RCA's, the difference in ground potential between the two
> componets (HU and Class D amp) was sooooo great it effected ALL the RCA's as
> the HU desperately tried to null out the difference. *You see, the other
> thing that intrigues me about your story is that at two feet you have this
> huge ground loop problem, yet at one foot it apparently completely goes
> away. *Logically, that's a little hard to reconcile as you would EXPECT (if
> your problem was caused by internal resistance due to this two foot length
> of four guage) that by cutting the length in half, your problem should
> logically be still there, but half as bad (as your ground differences should
> now be half as severe as they were before). * If the problem before was
> HUGE, by cutting the voltage differential in half would it COMPLETLY go
> away? *Hmmmmm.....
>
> Let me postulate something: I can't help but wonder if at two feet, your
> ground loop was so severe, you crossed some threshold on your HU (sucking
> current over your subwoofer RCA's) that made it impossible for it to isolate
> the ground differences amongst the other RCA outputs. *But at one foot,
> whatever ground-loop that might still be present would be small enough to be
> restricted to your subwoofer outputs only, and as ground-loops are typically
> high-pitched, they would be inaudible on a subwoofer system, and presto,
> your problem would APPEAR to completely go away. *Simply stated, at two feet
> your HU WAS OVERWHELMED, effecting all RCA's as it desperately tried to null
> out what to it was an enormous difference. *At one foot, the problem was
> resricted to your subwoofer output only, as it should be, and therefore,
> inauduble.
>
> I know, I know, I don't have enough to do. *That's what you're thinking
> right now. *I know it.
>
> It was just intriguing that at two feet the problem was huge, and at one
> foot it seemed to completely go away. *That just seemed to not entirely
> track for me and I was thinking of a reason why this might be so.
>
> Again, I'm NOT challanging what you are saying, just approaching this as an
> intellectual excercise. *Feel free to elaborate if there are more details to
> this story.
>
> Take care Lull,
>
> Nick

[MOSFET]

Yeh, that does change things a bit. If you were hearing the ground loop
over your subs then that sort of blows my theory.

Again, this discussion is more a waste of bandwidth than any
earth-shattering electrical discourse on the verge of finding a revised
theory of thermodynamics. I'm sure I wouldn't even have responded to your
post if I wasn't so damn bored still recovering from my operation.

in a nutshell, you may have been hearing the whine over the speaker outputs
on the deck, this would change the electrical propertise I was discussing as
well as the fact you were hearing the whine over your subs.

Because of these facts (curveballs), I think I'll leave this one alone. The
good news is that you fixed the problem, congradulations, and we'll leave
it at that.

And yes, thank you, I am very happy with my Kappa tweets. I again last
night spent several hours listening to dozens of songs and was absolutely
delighted at the detail, power, and imaging capabilities of these tweeters.
I was telling my wife and evil sister-in-law (she was responsible for
blowing one of my Class R tweets in the first place) who happened to be
visiting for several days (she's unmarried and lives alone), that I TRULY
believe at this moment in time, my car audio system has NEVER, EVER sounded
better than it does right now. Although the Class R tweets were very good,
after extensive listening I had to conclude the Kappa's were a little
better. Namely, the Class R's were silk and as is common with silk domes,
they just don't have the frequency response that metal tweets usually have.
My Kappas have a frequency response that goes over 30kHz and I could hear
harmonic overtones in many songs I had never heard before.

Yet unlike other metal domes I've owned in the past (MB Quart Q Series and
Boston Accoustic Pro Series) they don't "fatigue" the ears after a long
period of listening. This is supposed to be due to the fact that they are
not metal domes, but a type of ceramic material.

Anyway, I love them.

MOSFET




"Mister.Lull" > wrote in message
...
Oh Nick...

Now I'm going to throw a curve-ball your way.

When I say "once upon a time" this was probably 8-10 years ago, when I
was first getting in to this, um, sport (?). With the installation
I'm talking about, I was running 4 speakers right off the HU, and one
sub off of a class D amp.

Now, this doesn't change your overall theory, I suppose, just the
specifics.

First, I'll be honest, I don't remember if the whine was coming out of
the interior speakers - I DO remember the whine coming out of the
sub. 0_o The deck I was using didn't have a built in crossover, and
the amp said it was automatically crossed over at 300Hz (so I didn't
worry about it). But there was high pitched AND a low-pitched
undertone whine coming from the sub.

Weird, eh?

I always figured it was a difference in current between the power wire
and a long/poor ground (both were 4 gauge)...

~Mister.Lull

On May 29, 5:47 pm, "MOSFET" > wrote:
> Once upon a time, I attempted to ground a single Class D Subwoofer amp
> with a two foot length of 4 Gauge wire and the whine was unbelievably
> loud and obnoxious. Simply by shortening that same wire (ground to
> the same point on the chassis) by a foot (making it only 1 foot long),
> the whine disappeared completely.
>
> You know Lull, I thought about this.
>
> Remember, I'm still recovering from my heart operation so I have lots of
> time to think about things ;).
>
> And I can't think of a single time I ever had a ground loop issue that
> dealt
> with the subwoofer amp, PROVIDED you, and me in past installs, were
> feeding
> the subwoofer amp it's own output from the HU. The RCA outputs of a HU are
> isolated in such a way that although you certainly COULD be experiencing a
> ground loop via your subwoofer RCA's, I can't imagine you would HEAR such
> a
> high-pitch whine over your subs?
>
> So I'm assuming the ground loop noise was coming over your other speakers.
> And again, I THOUGHT that those outputs were isolated in such a way that
> you
> wouldn't hear such a ground loop unless your midrange amps were also
> experiencing a ground loop problem.
>
> Now maybe I'm way off on this issue, but let's suppose the curent draw of
> your Class D amp was so great that although the loop was only through your
> subwoofer RCA's, the difference in ground potential between the two
> componets (HU and Class D amp) was sooooo great it effected ALL the RCA's
> as
> the HU desperately tried to null out the difference. You see, the other
> thing that intrigues me about your story is that at two feet you have this
> huge ground loop problem, yet at one foot it apparently completely goes
> away. Logically, that's a little hard to reconcile as you would EXPECT (if
> your problem was caused by internal resistance due to this two foot length
> of four guage) that by cutting the length in half, your problem should
> logically be still there, but half as bad (as your ground differences
> should
> now be half as severe as they were before). If the problem before was
> HUGE, by cutting the voltage differential in half would it COMPLETLY go
> away? Hmmmmm.....
>
> Let me postulate something: I can't help but wonder if at two feet, your
> ground loop was so severe, you crossed some threshold on your HU (sucking
> current over your subwoofer RCA's) that made it impossible for it to
> isolate
> the ground differences amongst the other RCA outputs. But at one foot,
> whatever ground-loop that might still be present would be small enough to
> be
> restricted to your subwoofer outputs only, and as ground-loops are
> typically
> high-pitched, they would be inaudible on a subwoofer system, and presto,
> your problem would APPEAR to completely go away. Simply stated, at two
> feet
> your HU WAS OVERWHELMED, effecting all RCA's as it desperately tried to
> null
> out what to it was an enormous difference. At one foot, the problem was
> resricted to your subwoofer output only, as it should be, and therefore,
> inauduble.
>
> I know, I know, I don't have enough to do. That's what you're thinking
> right now. I know it.
>
> It was just intriguing that at two feet the problem was huge, and at one
> foot it seemed to completely go away. That just seemed to not entirely
> track for me and I was thinking of a reason why this might be so.
>
> Again, I'm NOT challanging what you are saying, just approaching this as
> an
> intellectual excercise. Feel free to elaborate if there are more details
> to
> this story.
>
> Take care Lull,
>
> Nick