kingyy
10-10-2007, 08:30 PM
For those who do not know, a ground loop is a problem where you hear that annoying buzz from the amps, where it changes pitch and tone with the revs of the engine.
The cause of a ground loop is where the ground voltage is not exactly 0 volts, usually due to impedence and resistance through the chassis, and if the stereo and amp are both powered from the same +ve point (usually the batter), but the grounding points are different, then you will get a ground loop almost 90% of the time.
Easiest way to avoid this is either grounding the amp directly back to the battery (although resistence in the cable run will cause other more annoying issues), or you ground the grounding points to a common spot.
This is more advanced audio install, but the best wiring is to have the amp as mentioned in my previous post, have the headunit constant also coming form the battery, or the jumpered somehow into the 4 gauge wire along the way.
With the grounding, use a 4 guage ground, which grounds directly to the chassis (yep, the chassis), then continues off to the chassis near the head unit (same ground style, with a u-clamp to ground it), then from there to the chassis next to the battery's 1st grounding point, and then meet up with the engine grounding point from the battery.
This way, your AMP grounds to the chassis, BUT you have now also grounded the chassis to the chassis next to the head unit (where you can then re-ground the headunit to), and then grounded that section (and the other section of the chassis) to the same ground as the battery.
Doing this will equalise the voltage throughout the length of the car, and therefore 99.9% eliminate the possibility of a ground loop.
Also, you use a larger grounding cable than the power cable, giving the Amplifier a much better ground.
Also, the reason I went a 4 guage from positive to distro, and then 8 guage from distro to AMP was because if you want to run a 2nd or 3rd, or 4th or more amps, you can run them from this distro (I tend to only run 2 amps from a 4 gauge feed).
The reason for grounding the AMP as early as possible, because the cable length will create resistance, which will alter the voltage value, thus causing ground loop.
IF you ground an AMP directly to the battery, it tends to spike and cut in and out when under large amounts of BASS (I did this with my first AMP install, and it was so bad I had to have the engine running to power the amp, but as soon as I limited the ground to 1 meter, and straight to the chassis, it stopped cutting in and out).
With grounding, make sure it's a GOOD GROUND, no point going "here's a bolt, it's got some paint, but it powers up, just stick it here", get the sandpaper out, scrub the paint away, bolt the cable to the chassis, and then get some clear-coat, or likewise colours paint, and paint OVER the wires, to protect the metal, that way the cable is grounded cleanly, but the metal is also protected.
With car audio installs, it gets very technical, and unless you install the entire thing properly, you will always have a bottle-neck in the system, for a nice sounding audio system, you cant have any compromise, otherwise dont bother doing it to begin with.
With my install, I have custom eathing kits that earth in 22 different points. I have double earthed head unit, double earthed AMPS, 3 amps installed (front, read, and subwoofer), boxed front split speakers (box for the midrange, box for the tweeters), boxed rear speakers, sound proofing in all doors, floors, and boot, rubber gromets between everything that bolts together to stop rattles, every sire soldered, shirnk-wrapped, and then tapped, all wires and looms in plastic cable wrapps, RCA and power cables run on seperate sides of the car to stop induction of noise, the only weak point in the entire installation is the stock as a rock rear speakers (the only mod to the rear speakers are Toyota Soarer front speaker boxes fitted to the rear speakers, this is to stop the boot-boxed free-air subwoofer from altering the air volume around the rear speakers
The cause of a ground loop is where the ground voltage is not exactly 0 volts, usually due to impedence and resistance through the chassis, and if the stereo and amp are both powered from the same +ve point (usually the batter), but the grounding points are different, then you will get a ground loop almost 90% of the time.
Easiest way to avoid this is either grounding the amp directly back to the battery (although resistence in the cable run will cause other more annoying issues), or you ground the grounding points to a common spot.
This is more advanced audio install, but the best wiring is to have the amp as mentioned in my previous post, have the headunit constant also coming form the battery, or the jumpered somehow into the 4 gauge wire along the way.
With the grounding, use a 4 guage ground, which grounds directly to the chassis (yep, the chassis), then continues off to the chassis near the head unit (same ground style, with a u-clamp to ground it), then from there to the chassis next to the battery's 1st grounding point, and then meet up with the engine grounding point from the battery.
This way, your AMP grounds to the chassis, BUT you have now also grounded the chassis to the chassis next to the head unit (where you can then re-ground the headunit to), and then grounded that section (and the other section of the chassis) to the same ground as the battery.
Doing this will equalise the voltage throughout the length of the car, and therefore 99.9% eliminate the possibility of a ground loop.
Also, you use a larger grounding cable than the power cable, giving the Amplifier a much better ground.
Also, the reason I went a 4 guage from positive to distro, and then 8 guage from distro to AMP was because if you want to run a 2nd or 3rd, or 4th or more amps, you can run them from this distro (I tend to only run 2 amps from a 4 gauge feed).
The reason for grounding the AMP as early as possible, because the cable length will create resistance, which will alter the voltage value, thus causing ground loop.
IF you ground an AMP directly to the battery, it tends to spike and cut in and out when under large amounts of BASS (I did this with my first AMP install, and it was so bad I had to have the engine running to power the amp, but as soon as I limited the ground to 1 meter, and straight to the chassis, it stopped cutting in and out).
With grounding, make sure it's a GOOD GROUND, no point going "here's a bolt, it's got some paint, but it powers up, just stick it here", get the sandpaper out, scrub the paint away, bolt the cable to the chassis, and then get some clear-coat, or likewise colours paint, and paint OVER the wires, to protect the metal, that way the cable is grounded cleanly, but the metal is also protected.
With car audio installs, it gets very technical, and unless you install the entire thing properly, you will always have a bottle-neck in the system, for a nice sounding audio system, you cant have any compromise, otherwise dont bother doing it to begin with.
With my install, I have custom eathing kits that earth in 22 different points. I have double earthed head unit, double earthed AMPS, 3 amps installed (front, read, and subwoofer), boxed front split speakers (box for the midrange, box for the tweeters), boxed rear speakers, sound proofing in all doors, floors, and boot, rubber gromets between everything that bolts together to stop rattles, every sire soldered, shirnk-wrapped, and then tapped, all wires and looms in plastic cable wrapps, RCA and power cables run on seperate sides of the car to stop induction of noise, the only weak point in the entire installation is the stock as a rock rear speakers (the only mod to the rear speakers are Toyota Soarer front speaker boxes fitted to the rear speakers, this is to stop the boot-boxed free-air subwoofer from altering the air volume around the rear speakers