I've added 3 amps into 2 different cars and the ground loop is driving me crazy.

My Latest is in a 06 civic coupe.

4 channel MTX amp.

4 gauge from the battery and into an 8 gauge splitter.

Power wire ran separte from the RCAs & Speaker wires.

8 gauge to the amp and 8 gauge ground wire (3 feet long) and i went to make sure i sanded to the bare metal of the chasis!!.

Still i'm having this huge probelm with ground loop (altnerator whine with increase in engine rpm)

 

did u run powerwire and rca on the same side? if not try to rca and get a ground loop isolator.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by turboekcivic &raquo;</TD></TR><TR><TD CLASS="quote">did u run powerwire and rca on the same side? if not try to rca and get a ground loop isolator.</TD></TR></TABLE>

Band aid. Here is why a ground loop isolater is basically a 1:1 transformer. The channels are coupled electromagnetically. There is no path back to ground. This does not fix the ground loop it only masks the problem.

My suggestion to the poster is to try and eliminate where the problem is comming from.

First just try the radio with no amp.
If alternator whine then you have a faulty radio ground or faulty vehicle ground. Either at the battery to chassis or motor to chassis.
Or Faulty Radio

Then try the amp connected a couple inches from the radio.
If whining try swapping to a different set or different brand of RCA's.
Connect a ground directly to the battery. If this fixes the problem then you have chosen a bad spot for your amp ground.

Now move the amp to the prefered mounting location and repeat.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nsxxtreme &raquo;</TD></TR><TR><TD CLASS="quote">
First just try the radio with no amp.
If alternator whine then you have a faulty radio ground or faulty vehicle ground. Either at the battery to chassis or motor to chassis.
Or Faulty Radio

Then try the amp connected a couple inches from the radio.
If whining try swapping to a different set or different brand of RCA's.
Connect a ground directly to the battery. If this fixes the problem then you have chosen a bad spot for your amp ground.
</TD></TR></TABLE>

I had the head unit powering all the speakers before and it have absolutely no problem or any kind of noise. So i guess the grounding of the head unit is good & the speakers are in good condition.

My RCAs & speaker wires run together. The power cable runs parallel with them but it's about 1/2 foot distance. The RCAs are cheapo wal-mart unshielded though....But how do i test to see if the RCAs are the cause without spending money? (i'm broke right now)

 

What is the make and model of the HU?

Run the RCAs down the middle of car and run the power down the batt. side of car, [pass. side on most Honda/Acura] and change the RCAs. 94

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kroze &raquo;</TD></TR><TR><TD CLASS="quote">The RCAs are cheapo wal-mart unshielded though....But how do i test to see if the RCAs are the cause without spending money? (i'm broke right now)</TD></TR></TABLE>
Use a different set of cheapo RCA's. I have had luck with cheap radio shack brand. Run them accross the carpet.

 

Today: I remove the RCA cables going into the amplifer. The alternator whine is still present.

It ruled out the Crappy RCA right? so it's probably the power wire, cheap speaker wires, ground?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kroze &raquo;</TD></TR><TR><TD CLASS="quote">Today: I remove the RCA cables going into the amplifer. The alternator whine is still present.

It ruled out the Crappy RCA right? so it's probably the power wire, cheap speaker wires, ground?</TD></TR></TABLE>

Assuming the amplifier is connected to the speakers that you hear the whine on. Then yes you probably have a really bad ground. Possible a cheap amp that's chassis is not isolated thus creating a second ground path.

If the speakers are connected to the stereo and you still hear the whine then you probably have a bad HU ground or antenna ground. Remember you need two ground paths to create a ground loop.

 

What do you mean, <TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kroze &raquo;</TD></TR><TR><TD CLASS="quote">Today: I remove the RCA cables going into the amplifer. The alternator whine is still present.</TD></TR></TABLE> do you mean unplugged them at the amp and you still have noise? I so.....

1-Check amp ground, redo it even if it looks good, [BTW what is the amps ground lead grounded to, and how?]

2- If amp chassis is grounded, [screwed to the cars chassis] unscrew it and check for noise.

3- Run a 16/18ga wire from the chassis of the HU to the chassis of the amp, just run it over the carpet and seats until you know if it will work, check with amp chassis grounded and not grounded, I can't remember the last MTX amp that I mounted to cars chassis, I have always isolated them, [1 of 3 things can happen, 1-nothing, 2-the noise gets worse and 3- the noise is gone].

Again, make and model of HU? 94

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fcm &raquo;</TD></TR><TR><TD CLASS="quote">What do you mean, do you mean unplugged them at the amp and you still have noise? I so.....

1-Check amp ground, redo it even if it looks good, [BTW what is the amps ground lead grounded to, and how?]

2- If amp chassis is grounded, [screwed to the cars chassis] unscrew it and check for noise.

3- Run a 16/18ga wire from the chassis of the HU to the chassis of the amp, just run it over the carpet and seats until you know if it will work, check with amp chassis grounded and not grounded, I can't remember the last MTX amp that I mounted to cars chassis, I have always isolated them, [1 of 3 things can happen, 1-nothing, 2-the noise gets worse and 3- the noise is gone].

Again, make and model of HU? 94 </TD></TR></TABLE>

The 8 gauge ground is attached to the seatbelt bolt which connect onto the car's body. I sanded it down to bare metal before putting it on.

I don't think it's the amp as because i had it on a 3/4 MDF board and it still have alternator whine.

The head unit is a pioneer premier 670 with mp3. 3 2v rca output.

 

I think it's the power cable that's bringing all these noises. What can i do?

 

-add a 4ga ground from battery negative to frame ground
-remove amp ground from seat bolt to a new fresh spot on the cars sheet metal

this should help

 

not sure if this will make a difference but 4 outta the 5 installs i did w/ 4 channel MTX amplifiers picked up the ground loop. Have you tried using a different amp?

 

It's not the amp. In the past, i've used a kenwood 4 channel, sony xplod 4 channel, various mTX 4 chan.

in all different cars (90 supra turbo, 96 accord, 92 300z, 06 civic) and all have the same problem. Could it be the speaker wiring going from the amp to the head unit? or is it the power & ground wire itself is the cause.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kroze &raquo;</TD></TR><TR><TD CLASS="quote">It's not the amp. In the past, i've used a kenwood 4 channel, sony xplod 4 channel, various mTX 4 chan.

in all different cars (90 supra turbo, 96 accord, 92 300z, 06 civic) and all have the same problem. Could it be the speaker wiring going from the amp to the head unit? or is it the power & ground wire itself is the cause.</TD></TR></TABLE>

Umm.... maybe its your installation technique perhaps? We all have given a few good tips to help you out. Try them out..they may be the cure to your noise issue.

 

don't ground it on seatbelts

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by audioroach &raquo;</TD></TR><TR><TD CLASS="quote">-remove amp ground from seat bolt to a new fresh spot on the cars sheet metal</TD></TR></TABLE> Why?

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by igo4bmx &raquo;</TD></TR><TR><TD CLASS="quote">don't ground it on seatbelts</TD></TR></TABLE> Again why?


There is no better place to ground an amp then to seat mounting and seat belt bolts, large ring terminals allow for large contact area to cars floor-pan, and with more torque then you can possibly get with a sheet metal screw, all without drilling a hole in the floor-pan, I have been doing so for over 30 years, with 1000s of amps of all kinds and have never had it be a problem, and if there is noise on a system it is never because the amp(s) is/are grounded using a seat belt bolt or seat mounting bolt., any bolt or stud, [and nut] that will allow contact with floor-pan is preferable over drilling a hole, [breaking rust barrier] in floorpan.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by audioroach &raquo;</TD></TR><TR><TD CLASS="quote">-add a 4ga ground from battery negative to frame ground
this should help</TD></TR></TABLE> It will definitely help, it may do diddly about the noise.
One more time, Pioneer HU with another brand amp and there is noise, it's as if Pioneer did it on purpose.

I have had more noise problems with Pioneer HUs, when used with other brand S/P and/or amps, then any other brands, sure glad we dropped the line. kroze if you can, plug another HU, [brand] into the system and see if it changes anything.

Have you tried another set of RCAs yet, farther away from the power wire? 94

PS, before anyone jumps all over me about the amp ground, don't bother, been there, done that.

 

Hrm... all i ever bought were pioneer head units lol.

I have a spare HU but it's also pioneer. Hehe. Anyway, i'll try all the stuff you suggest when it's warmer out

It's cold as heck here in jersey.

Thanks for all the suggestion guys.

 

someone on another forum also claim that pioneer HU are notorious for noise problem...

 

I should have said most other signal processors and amps, also, I will say I have never had a noise problem when they are connected to Pioneer amps.

I have also found over the years that 99% of the time a "noise" problem can be solved without changing, [other then defective gear] any of the equipment, sometimes the fix is easy, sometimes not, do not be surprised if it turns out that it had nothing to do with the HU, amp or your install, it could be a bad/poor batt. to chassis ground or an alt. on it's way west.

I bet if you had the HU pulled, [so RCA outputs are accessible] and amps inputs are accessible, most any shop will plug in a set of RCA leads they know are good, [only takes 30 sec. if you make it easy] we would, so you can see if the RCAs are the problem so you do not have to buy them if you do not need them. 94

 

i have a pioneer 3800 HU and an mtx 204 (4channel) and also an MTX 302 (2 channel)
running everything. and i have no noise whatsoever grounded everything off rear deck. using genericRCA's and 8g wire.