Grounding..

[[email protected]]

I know I've written about this before somewhere but can someone set the
record straight. How can I ground my amp well. I have greased the
ground tab with bicycle grease and sanded then cleaned the area with
water, then dryed it will a paper towel under the bracket of the
passenger seat of my car. Then bolted it down.

The reason that I ask is that I have an SPLX SPLA-450 450watt amp. It
makes this hissing sound when I have it on low volume. I have 4
speakers connected to it even though its a 2 channel amp.

Please help

Dan

[e-nigma]

> wrote in message
oups.com...
>I know I've written about this before somewhere but can someone set the
> record straight. How can I ground my amp well. I have greased the
> ground tab with bicycle grease and sanded then cleaned the area with
> water, then dryed it will a paper towel under the bracket of the
> passenger seat of my car. Then bolted it down.
>
> The reason that I ask is that I have an SPLX SPLA-450 450watt amp. It
> makes this hissing sound when I have it on low volume. I have 4
> speakers connected to it even though its a 2 channel amp.
>
> Please help
>
> Dan
>


It sounds like you have the amp gains turnes all the up.

[Matt Ion]

e-nigma wrote:
> > wrote in message
> oups.com...
>
>>I know I've written about this before somewhere but can someone set the
>>record straight. How can I ground my amp well. I have greased the
>>ground tab with bicycle grease and sanded then cleaned the area with
>>water, then dryed it will a paper towel under the bracket of the
>>passenger seat of my car. Then bolted it down.
>>
>>The reason that I ask is that I have an SPLX SPLA-450 450watt amp. It
>>makes this hissing sound when I have it on low volume. I have 4
>>speakers connected to it even though its a 2 channel amp.

A chain is only as strong as its weakest link, and a ground is only as clean as
its worst connection. No matter how good you make the amp ground, if the
battery ground to the body/chassis isn't solid, you won't get a good connection.

> It sounds like you have the amp gains turnes all the up.

Yup... in which case you're greatly amplifying ANY noise coming from the deck or
the interconnect wiring.

[RG]

To help get a better ground run a short length of 8 gauge ground wire from
the negative battery post to the car chassis. This helps quite a bit as the
usual factory grounding to the engine block leaves a lot to be desired. And
then, as suggested in the other replies, set your amp gains up properly.
They should not be near max unless your HU has very weak output at the
RCA's.

- RG

> wrote in message
oups.com...
>I know I've written about this before somewhere but can someone set the
> record straight. How can I ground my amp well. I have greased the
> ground tab with bicycle grease and sanded then cleaned the area with
> water, then dryed it will a paper towel under the bracket of the
> passenger seat of my car. Then bolted it down.
>
> The reason that I ask is that I have an SPLX SPLA-450 450watt amp. It
> makes this hissing sound when I have it on low volume. I have 4
> speakers connected to it even though its a 2 channel amp.
>
> Please help
>
> Dan
>

[MOSFET]

> To help get a better ground run a short length of 8 gauge ground wire from
> the negative battery post to the car chassis. This helps quite a bit as
the
> usual factory grounding to the engine block leaves a lot to be desired.
And
> then, as suggested in the other replies, set your amp gains up properly.
> They should not be near max unless your HU has very weak output at the
> RCA's.
>
> - RG
>
This is good advice.

Another little trick I always do is run a 12 guage wire between your HU
chassis (or HU ground) to your amp ground. This will help ensure you do not
have any ground loop issues (that will cause alternator whine) between your
HU and amp.

MOSFET

[Matt Ion]

RG wrote:
> To help get a better ground run a short length of 8 gauge ground wire from
> the negative battery post to the car chassis. This helps quite a bit as the
> usual factory grounding to the engine block leaves a lot to be desired.

Yup, that's what I'm talking about, upgrading the battery/chassis ground. A lot
of cars make their main ground cable from the battery to the engine block,
because it has to return the starter current, but then they use only a very
small connection from the block to the chassis, and/or sometimes a small wire
from the battery negative to the chassis (my Accord by default had 14ga. for
both!)... but if you're running an 8ga. power wire (and your amp actually uses
that much current), you need at least an 8ga. ground for proper performance as
well.

Remember that when the car is running, you're actually getting your power from
the *alternator*, not the battery, so you need to make sure you have a good
ground between the *block* and the chassis. If there's already a good ground
between the block and battery, you can get away with just improving or adding a
ground wire from battery to chassis. For best results, upgrade *both*.

Watch what you connect to on the block, BTW... friend of mine connected the
block/chassis wire to one of the valve-cover bolts on his older Civic and
couldn't figure out why it didn't work right: the vavle cover is isolated by the
block by a rubber gasket, and the studs/nuts by rubber-lined washers.

And do put the same care into cleaning off and providing a solid ground point on
the body/chassis, that you did with grounding the amp itself.

> then, as suggested in the other replies, set your amp gains up properly.
> They should not be near max unless your HU has very weak output at the
> RCA's.

Ditto!


> - RG
>
> > wrote in message
> oups.com...
>
>>I know I've written about this before somewhere but can someone set the
>>record straight. How can I ground my amp well. I have greased the
>>ground tab with bicycle grease and sanded then cleaned the area with
>>water, then dryed it will a paper towel under the bracket of the
>>passenger seat of my car. Then bolted it down.
>>
>>The reason that I ask is that I have an SPLX SPLA-450 450watt amp. It
>>makes this hissing sound when I have it on low volume. I have 4
>>speakers connected to it even though its a 2 channel amp.
>>
>>Please help
>>
>>Dan
>>
>
>
>

[[email protected]]

Cheers Guys.
Very good advice.
I thought that my amp might be crap and thats why it keeps on making
sounds,
for example when i play a cd and change track you can here the laser
moving inside,
as though that sound is being amplified.

cheers

dan

[Matt Ion]

wrote:
> Cheers Guys.
> Very good advice.
> I thought that my amp might be crap and thats why it keeps on making
> sounds,
> for example when i play a cd and change track you can here the laser
> moving inside,
> as though that sound is being amplified.

That's likely a grounding problem, possibly a ground loop. If
improving/upgrading the grounds doesn't work, visit a local car audio shop and
ask if you can test a ground-loop isolator - they normally run arounf $25-$35
but most shops will be glad to let you try on first to be sure that'll fix it
before you buy one.

[GregS]

In article <stc4h.274192$1T2.186208@pd7urf2no>, Matt Ion > wrote:
wrote:
>> Cheers Guys.
>> Very good advice.
>> I thought that my amp might be crap and thats why it keeps on making
>> sounds,
>> for example when i play a cd and change track you can here the laser
>> moving inside,
>> as though that sound is being amplified.
>
>That's likely a grounding problem, possibly a ground loop. If
>improving/upgrading the grounds doesn't work, visit a local car audio shop and
>ask if you can test a ground-loop isolator - they normally run arounf $25-$35
>but most shops will be glad to let you try on first to be sure that'll fix it
>before you buy one.

$17 at Rat Shack.

greg