hooked up 4 channel amp in boot now have engine noise??

[phatman3801]

just hooked all my speakers up to a 4 channel which is in the boot, im running two sets of rcas on one side of the car and the main power cable down the other side, and since i have put the amp in when the engine is running i get inference from the engine through the speakers, ive tryed moving the earth for the amp but its just the same! any ideas on how to get rid of it???

[[A NINJA]]

make sure you have good quaility cables, and also keep them as far awwy as pos from the main power cable. It maybe your head unit isnt healthly!! try

http://forums.nzicemag.co.nz/

they help good!

[Alex B]

Yeah, didnt plug in the rca's while they were going did ya?

[DeeCee]

a) what headunit
b) what amplifier
c) what wiring (and how did you wire it)
d) what battery
e) whatever else you think will help people in helping you

[matt dunn]

make sure you have good quaility cables, and also keep them as far awwy as pos from the main power cable. It maybe your head unit isnt healthly!

From what I hear it is best to run the RCA cables down one side of the car and the power ffed to the amp down the other.

Matt

[Alex B]

Thats the theory. Has any one ever had it make a noticiable diffrence tho?

[DeeCee]

from what you all read and hear its actually a falsehood..
RCA's are AC, power is DC.. so unless the power wire is creating and collapsing magnetic fields then it can't generate noise within the RCA cable.. the main problem is having a whole bunch of RCA cables next to each other.. i tend to spread them 10mm apart

[matt dunn]

from what you all read and hear its actually a falsehood..
RCA's are AC, power is DC.. so unless the power wire is creating and collapsing magnetic fields then it can't generate noise within the RCA cable.. the main problem is having a whole bunch of RCA cables next to each other.. i tend to spread them 10mm apart

Correct the power is DC,
but as it travels through the wire and the current increases and decreases through that wire, it varies the strength of the magnetic field,
kinda like building and partially collapsing the field.

But hey, I still may be a falsehood.

[Blackrazor]

It doesnt reverse direction, which is required to create an AC waveform. Regardless of flux in DC strength, it always flows in one direction, or else it wouldnt be DC Whereas audio is AC

Having said that, theres no detrimental effects to running them seperate either, so if it makes you happier, do it.

[Lloyd]

*believes Matt*

You've got a changing current which is a changing magnetic field, the magnitude of the change (rather than the direction) dictates the field. If we needed AC to induce a current then ignition coils wouldn't work...

[Jazza]

My friend has the same problem through his rear speakers, an english version is basically to say, do your wiring down the opposite side of the car to your battery and it will generally fix it. What happens is when you wire it down the same side the current from the alternator (So ive been told, i could be wrong) interferes and you hear your revs through your speakers.

Let me know if im wrong.

[Alex B]

OK but once again, has any one accualy does this and had it fix the fault?

[soven]

I run all of mine on the same side and no noise at all.

[[A NINJA]]

I ran power cable and RCA's togather and I got engine noise, when I spilt the two apart the engine noise when bye bye!

[DeeCee]

i've done both and with extreme noise issues, seperating the RCAs does work.. best practice is to do both really..

[gordon77]

i have the same problem (noise), the battery is in the boot in my case and the rca cable runs along the other side to where the cable to the engine bay goes.

i have tried moving the amp earth around but to no avail.

one of my mates suggested a noise supressor??? i dunno what it does or how it will help or not...

deecee - are you saying run a single (left) rca down one side of the car and run the other (right) down the other side???

[DeeCee]

i'll outline the problem that was encountered.
Various new pioneer headunits have a problem with the RCA earth track, in that if its too small for amps that require more earth through the RCAs it blows leading to noise issues.

The system i worked on had a pioneer unit running to some caliber amps and ran DD speakers and subs. Noise was coming from vifa tweets on the dash - alternator whine.. very frustrating for the owner of the car..

So basically i spent around 15 - 20 hours over a couple of weekends trying to figure out the problem.
1) re-did all grounds - amps, heatunit, battery, engine earth
2) changed layout of all wiring going through the car - took out seats and carpet and relaid all the wire in the car incl power, rca and speaker
3) cleaned all electrical points with wire brush incl battery terminals, battery terminal posts and removing alternator

because i did this systematically there were noticble results from each step - i just outlined the basics of each major step.. understandably you're not going to find out dong big jumps..

when you lay your RCA gordon, you dont' have to seperate the RCA by laying to either side of the car, all you have to do is lay them 10 - 20mm apart, stick down to the floor with gaffer or duct tape to hold them in place.
There is no one solid answer for solving noise issues, its just a "see what you can do to make a difference". Ideally everythign should be done on the initial install.. some peopel just dont' get noise issues understandably - each case is different

[sergei]

The noise created is amplified noise from alternator. The noise appear due to ground loops (google for it). In hifi it is known as 50Hz hum (becuase 50Hz is mains frequency). You can fix it (in most cases) by isolating signal ground from amp ground, by using this:
http://www.jaycar.co.nz/productView.asp?ID=AA3085&CATID=24&keywords=&SPECIAL=&form=CAT&ProdCodeOnly=&Keyword1=&Keyword2=&pageNumber=&priceMin=&priceMax=&SUBCATID=563

Noise is there becuase probably you have a cheap amp (power ground is not isolated properly to signal ground). As amp has a high gain it works a amplifier of the pulses in the groung loop (between stereo and amp - it works as a antenna) created by alternator..

[DeeCee]

noise supressors a) dont' work and b) are generally a waste of money there sergei. When there is noise you have to go in and fix it properly ie spend hours looking for the cause of the problem.
its too simplistic to just say that "a noise supressor will work"

and trust me - noise can appear in all types of systems, not just with cheap amplifiers

[Jazza]

Agreed, ive seen noise issues caused by the alternator in a 3 grand alpine system.