interferance help!!

[hg premier]

ive got a four channel amp running a pioneer sub and two 6.9 speakers

when i turn the ignition on it seems like the fuel pump is interfering with the amp
then when i start it it wigns with th revs of the engine

my dad said i need a resistor

what do you guys think??
please help giving me a headache

[holdenboy]

Most interference problems are caused by poor earthing.

Where have you earthed the amp?
Did you sand the area back to bare metal?

[Luke0011]

Ok you have what is called engine noise or whine, being caused by the alternator, there are many reasons why this is caused, can you describe how you installed it, what head unit you have. Where you have earthed it, what type of connections you have used, size of wire. The location of the amp and how the wiring is run, is it all 2nd hand, what brand of amp. How old is the alternator, battery. All this info helps to try and point you in the right direction. Cheers

[tr3nt]

Wouldn't a simple solution to be to seperate the RCA wiring from the power / earth cabling. This is all I've ever done with my installs, works a treat.

[holdenboy]

I honestly dont think separating power and RCA cables is a big issue these days (with double insulated and twisted pair RCAs).
It was necessary a few years ago, but a while ago i decided to run them down the same side (and taped together) in a mates VY commodore, used double insulated RCAs and didnt have any problems.

Anyway, ive noticed alot of people earthing amps off to un-suitable locations, and not making a proper connection to earth.....this could be whats happening but without knowing where / how it was earthed i cant say for sure.

[Luke0011]

Wouldn't a simple solution to be to seperate the RCA wiring from the power / earth cabling. This is all I've ever done with my installs, works a treat.

Did you bother to read the first post or just mine, how would you know if its run together or not, and simple solutions of seperating the rca and power and earth cables just proves the amount of installs you do compared to the 1000's i do. Try and help its appreciated, but just read his post first, engine whine is not just caused by incorrect layout of wiring.

Understanding how the system is put together and what products are used makes it easier to diagnose the problem he has. works a treat, not even knowing if he mounted the AMPLIFIER on top of the alternator with 25 metres of power wire wrapped around it as well as some around the fuel pump not to mention any other motor in the car might perhaps make you wonder????????

[hg premier]

a mate gave me the amp cant remeber brand off my head
pioneer sub brought brand new 5months ago
6/9 i brought brand new 1 year ago
head unit is a pioneer not to flashy but

all the wires are running down the passenger side

earth is on a bolt near tail light

using a sony wiring kit

not sure on how old battery and alternator are i havnt changed them in the past year

the amp is mounted on the bak of the sub box

thx

[Luke0011]

Well its standard practice to run RCA wires from the headunit down one side of the car and the main power wire from the battery down the centre or other side of the car to the amp. Try to keep them away from each other as much as possible and if the wires do have to come close to each other which is obvious as they both go to the amp then make sure the cross perpendicular and not along side each other. This eliminates the potential for electromagnetic interference being induced into the RCA wire and causing the engine noise.

Being that you said its a pioneer headunit, the quickest way to find why the engine noise is there is to first change or temporarily wire up another head unit to see if the engine noise disappears.

The reason i say this is because Pioneer headunits have a surface mount resistor on the RCA outputs that very frequently blow and cause the engine noise because a lot of people unplug the RCA plugs or plug them in while the Pioneer headunit is on. This is very easy to do and if you did buy the head unit 2nd hand chances are the resistor has already blown. Do you remember plugging in the RCA cables or unplugging them either at the amp or the headunit while the Pioneer unit was on.

If so it costs about 80 to fix and replace the resistor, take it down to your car audio store. If the static is still there with another unit plugged in then definatly need to move the power wire away from the RCA cables.
Then if problem still there the most likely cause is the amplifier itself.
Let me know how you go.

[holdenboy]

You can also try to isolate the head-unit without trying a new unit by removing the unit (still plugged in), and getting a small piece of wire, while the unit is on and playing music touch one end to the metal chassis of the head-unit and then touch the other end of the wire to the outer "ring" of the rca plug.
If the noise disappears then its the RCA output in the head-unit, and as Luke said its $80 to get fixed (probably better off to spend $100 and buy a new unit).

[hg premier]

took out the the head unit yesterday
and tested another one in its place and played music loud and clear soo went for a trip to jbhifi and brought a new pioneer head unit thx for all the tips

[holdenboy]

Cool, just make sure when your plugging / unplugging the RCAs at either the head-unit or amp to turn the stereo off.

[anarklov3r]

I thought it would be best to just post here.

Im having the exact same issue in my car. (VXII Acclaim)

I've installed RCA preouts on my stock VX Headunit (which work fine, tested in another car, and outside the car hooked up to home stereo on bench)

Kicker ZX700.5 Amp mounted upside down on a wooden place under parcel shelf.
Streetwires 4g AMP Power kit run down drivers side.
2x RCA's (Double insulated + twisted) run down passengers side

kicker 6x9's
kicker 6" splits
kicker 12" sub
not going intomodels, frankly it doesnt really matter)

I get engine noise that increases with revs. Can be heard once fuel pump kicks in.

Ive connected it like so:

1)Grounded battery to chassis with gold terminals crimped and soldered to 4g wire, aprox 10-15cm. Sanded terminals to bare metal
2)crimped + soldered 4g wiring kit for battery, sanded terminals and attatched
3) run power through clutch gromit and down drivers side
4) run pu behind rear seat into boot.
5)grounded amp to the back of rear seats exposed seat belt bolt (tried moving to a whole i made myself, still same issue) again, sanded to bare metal.

RCA's run down passengers



Ive tested headunit ground by earthing off rca outer ring to chasis, same issue.

ive put in a brand new pioneer from a mates car, and taht also gets engine noise.


ATM im running RCA's direct to amp with a 2x RCA to 1x 3.5mm adapter, and using my iPhone directly. (amp set to high level input). With nothing connected, i get engine noise. With ipod connected it runs fine.

Ive tried changing amp grounding, no effect. tried re grounding battery, nothing.
Battery is 2 months old (one of those solid gel type batteries)


Ideas guys?

[Luke0011]

hg premier - Good you worked it out quickly and appreciate the thanks

anarklov3r - First of all. awesome amp but caused me more pain than its worth.
This is why i hate 5 channell amplifiers.
I would like to run over some points you are obviously familiar with but are needed to be made aware of again so I can determine what the problem is in the quickest way possible.
I personally installed one of these amplifiers and remember a remote wire needed to be used as i was using a factory head unit and couldnt get the amp to turn on using dc offset or signal sense. Please make sure you run a seperate remote wire from your yellow wire at the factory eurovox radio harness. I have seen 2 installers blow this amp up from not following instructions.

DO NOT SWITCH ANY SETTINGS WHILE AMPLIFIER IS ON AND DO NOT DISCONNECT RCA PLUGS WHILE ON ESPECIALLY THE CROSSOVER SETTINGS FROM HI TO LOW OR OFF. IF YOU HAVE DONE THIS THEN STOP PULL THE AMP OUT AND TAKE IT BACK TO WHERE YOU GOT IT FROM>

You can only adjust the input gain level and the adjustable crossover on the top panel and bass boost. This is a complex class AB and D multi channell amplifier that uses up to 6 channels of line level ( LOW ) or high level ( SPEAKER ) inputs.

You have said you installed preouts to the vx factory unit. Explain exactly how you have done this. If you have converted the 4 speaker wires correctly to 4 RCA plugs then you are on the right track. Make sure the wires are positive into the middle pin. Waste of time to buy a LOC ( LINE DRIVER )

This site below lists problems you may come up with.
Please help Weird problem with Kicker zx700.5 [Archive] - TigéOwners.com

The 3 switches next to the AMP2 are set as follows. Sub is set to AMP1
Input level is set to LOW. Fader will depend weather or not you can get clean sound from using 4 channel in, some applications require only a 2 channel high level in.

Please remove the amp from your current mounting position. The amplifier is not designed to be mounted upside down as the heat sinks are located on top and around the amp. The heat will travel back into the amp shortening its life dramatically. There will be no warranty when it cooks.

IF ALL THESE STEPS HAVE BEEN CARRIED CORRECTLY OUT PROCEED BELOW

Firstly to set your mind at ease your iPod test has proved 100% that the amplifier and its power and speaker connections is not the cause of your engine noise. You said you have used a seperate 2x RCA to 3.5mm adapter to plug the iPod in and not using the rca you have run in the car. If that is the case then so far you know without a doubt that the amp is ok other than its mounting position. The engine noise being present when iPod not connected is normal.

The only thing else it possibly can be is the RCA wiring run incorrectly over the power
wire. PM me if you need to chat
Cheers Luke

[anarklov3r]

1) I have used a remote wire straight from the 12v Acc wire to the amplifier. It turns on fine, and works great with my ipod connected. I can crank it up full blast and not activate protection, and it never overheats, even in the recent super hot days. I never plug in RCA's and change from hi-low inputs while amp is turned on, common sense

I know its not the amp thats faulty, since i took out the 4ch MTX amp out of my other car to test that, and that does the exact same thing.


I've also tried running the RCA's straight down the middle of the car, across the seats, over the console to the headunit, and i still get noise.

I installed my RCA preouts as per this guide : VT/VX Low Series Head Unit RCA since im fairly handy with a soldering iron.

Because my ipod works without engine noise, i suspect the problem is a grounding loop occuring somewhere (since thats the only difference, ipod isnt groudned to car, where as the headunit is)
but i have no idea on how to fix this!

Im so fed up with it. I was tempted to just take it to a car audio joint and get them to fix it, but at an hourly rate, will cost me thousands of dollars to sort this out! lol!

[Luke0011]

That mod is a complete waste of time and effort, seriously why go to all that trouble, your also creating so many more ways for the system to either get damaged and or not work thus creating more hassle and stress for absolutley no reason at all. The rca cables can get pinched when sliding back the unit, very easy to get dry joints on a computer soldered circuit board, very easy to cross wires over shorting the amp out and the mtx as well, Your mate could have done something to his "brand new unit" or the now faulty amp has damaged your mates. the boom box you used could be a hunk of junk.
Did you try a seperate 12v supply when you powered up the boom box with both units.
Try and think if you may have done something to upset the amp or unit. Apart from already doing it.

As well as soldering 4 gauge terminals is not recommended, lets damaged a wire thats thick and introduce more ways to add resistance and oxidisation.

Check the rca running along the the car. does it run parralell with the power wire at any point.

eliminate power wire and rca cable by using brand new non soldered connectors,

check power and earth with a DM and check various spots. Do this with engine running, check everyone and evey body
Disconnect RCA cables


Not trying to have a go at you mate, i now have a very strong suspician there are things that have been done to the car that even you would be aware of. I am fairly confident now that if i ran a new set of rca's, temporarily wired a brand new unit that i myself un boxed as well as a brand new

Have you tried plugging your ipod into the rca cables at the head unit to confirm its not picking up the static down the line, have you operated the cross over switches while the stereo is on? have you honestly tried the mtx the same way as the kicker, home stereo with both eurovox

[anarklov3r]

I did this to my stock headunit because
1) i dont care if i break it, its temporary. Im a uni student, and seeing as my stereo works fine with my ipod direct, ill only spend the $400 on a headunit if i have to.
2) i had all the parts at home and an hour of my time

When i tried my MTX amp, i literally disconnected my kicker, and plugged in my MTX, EXACTLY the same. WHen i got the same results with that, that is when i pulled out my stock headunit and connected it to the speaker setup i have in my garage using a spare battery to power the headunit, with RCAs connecting HU directly to stereo.

When my ipod is connected to the RCA's running down the side of the car and up through the dash, it still works perfect. my rca's arent pinched. and it does not run parallel with any wires but the door looms wires for electric windows.

When i tried the pioneer HU on my kicker amp, i disconnected my mates wiring connector for his car, and plugged it into mine with the car off, obviously. Still getting engine noise. When we put his pioneer back into his car, it worked fine.

So

Its not his headunit, or my headunit.

Its not my amplifier because the MTX has the same issue.

Its not the RCA leads, because ive tried running a pair through the middle seat in the back of the car, over drivers seat and into the deck. (we didnt push deck into car so we dont pinch cables)

Its not the grounding in the boot, because ive tried in different locations, both stripped to bare metal.



And im fairly confident that even if you did put a brand new unboxed HU, brand new amplifier, brand new RCA's, you would still have the same issue, because i have tried replacing them all with something else. I have even tried moving my power lead out of the car (eg pulled out of engine bay with whatever slack was left, and pulled out and away from door sills while trims were off)

[holdenboy]

When my ipod is connected to the RCA's running down the side of the car and up through the dash, it still works perfect. my rca's arent pinched. and it does not run parallel with any wires but the door looms wires for electric windows.

So if you connected your Ipod to the RCA cable and it worked fine, then i think its your head-unit.
When you connected your mates Pioneer head-unit, how did you connect it to your car?
You said you unplugged his unit and then plugged it into your car, how so? You would need the wiring plug? I may have mis-interpreted that though.

Anyway, my vote is a faulty head-unit / RCA mod.

[anarklov3r]

My mate has got a pioneer - iso / iso - holden cable. It was a simple unplug and connect. His also had noise when connected to my car.

I think the reason im getting noise is because the headunit is grounded to the car. I think im getting some sort of earth loop. Since my ipod isnt earthed to the car i dont get this noise.

[holdenboy]

Hmm, well if you think its an earth loop, try this:
http://www.jaycar.com.au/productView...5&form=KEYWORD

[anarklov3r]

Yer holdenboy, i was thinking either that, of maybe a capacitor for my amp would solve the issue.

[holdenboy]

Capacitor wont solve an interference problem.

[anarklov3r]

Ok, just an update, i tried to fix the ground loop again today, completely pulled apart my car again.

Regrouded amp in another location.
Re-did the factory ground for the headunit to another location
ran constant power straight from battery

After all that, it was even worse!

I tried running ground straight to battery from HU, worse again.

I tried running amp to battery ground directly, same problem


Went to jaycar, and purchased thost earth loop isolators, they sort of worked, i could still clearly hear the whining sound, but not as loud. It was bareable, but, i lost all range in my audio frequencies! I had no bass, no treble, just heaps of midrange. It sounded very muddy.

I then went back and purchased an in like power noise filter, made no difference at all.


Im convinced there is another electrical fault in the car that im not qualified to fix. Im going to have to take the car to an auto electrician soon to fix this (i loose my liscence in 2 weeks for 3 months) so i might even do it once i get it back.

All in all, i wasted my day off from work hahahaha

Thanks for your help though guys.

Oh, i also removed the fuel pump relay to see if that was doing it, no go

It only does it when its in ignition. in Acc it works perfect, even hooked up to my DIY modified headunit. Its only once its turned over to IGN it does it.

[Luke0011]

Try grounding the headunit without the antenna plugged in to the amplifier's ground point only. hold the unit in your hand so its not being grounded anywhere other than the earth to the amplifier. Play a cd a see what happens. I can suggest if your car is going to be off the road for a while and your willing to leave the car at my car audio shop for a few days, i might be able to try a few things without a huge cost to you. Sort of like work on it in my own spare time. Im in the eastern suburbs. Cheers

[SikVP3]

Alternator interfereance.
Try and Earth a wire from your RCA plugs (The end that plugs into your Head unit) Earth the red one i think it is, and screw it to your head unit, worked for me.

Sik.

[Luke0011]

Read the posts, already tried that