Most installers can't answer this one


New member
Username: Djkatana

Phoenix, AZ Usa

Post Number: 2
Registered: Mar-06
I am installing a Pioneer 4-Channel Amplifier (GM6200F) to a stockdeck using the built in speakerlevel inputs.

•60 watts x 4 at 4 ohms
•4-channel crossovers •Speaker level inputs
•CEA 2006-compliant

Here is what most installers can't figure out......

When I install the Amp, engine noise comes through the speakers when you speed up or slow down using stock decks. Every installer recommends a RCA conversion Kit, but every installer also says the noise will still be there, but not as loud.

Pioneer says the ground loop which is created should not be there and the conversion kits are actually the reason why they decided to add this feature to their amps becouse the kits themself cause the loop.

How do you get rid of this sound without buying an unwanted aftermarket deck or an RCA conversion kit?

If you don't know, don't try to fake it.

Gold Member
Username: Tjmutlow

Post Number: 1759
Registered: Sep-05
i do not know exactly with that setup, but sometimes it comes from the alternator itself, and it can not be gotten rid of. and to be honest, even if you put an aftermarket radio, i would bet you have the noise still. it has to do with the amp, it is amplifying the noise....

Gold Member
Username: Illuminator


Post Number: 2784
Registered: Apr-05
You might want to try a Noise supressor:

Platinum Member
Username: Glasswolf

Wisteria, Lane USA

Post Number: 11403
Registered: Dec-03
amp could be damaged, which I've seen happen.
the amp's ground point could be the problem.
you could use a LOC similar to the PAC OEM1 which uses a T-harness on the factory wiring to tap into the factory harness and give you RCA line outs. It also allows you to adjust the line driver for each input to balance the LOC to the line voltages of your factory system.
This won't produce any loop, and is a better solution than the $10 LOCs most shops use that just splice into the rear speaker wires.

first, I'd move the amp's ground, and try re-routing the main power line in case it wound up near a coil of a wire for the ignition system, which is also a common cause of alternator whine.

New member
Username: Djkatana

Phoenix, AZ Usa

Post Number: 3
Registered: Mar-06
This is a New Amp out of the box.
In regards to the noise supressor....they do an Ok Job, but most new vehicles have noice dampining foam throughout the engine compartment and the noice supressor needs metal on metal contact.

Glass Wolf what Loc do you recommend?

Platinum Member
Username: Glasswolf

Wisteria, Lane USA

Post Number: 11411
Registered: Dec-03
a: new or not it can still be a bad amp.
b: PAC OEM-1 for the LOC, with appropriate harnesses
c: find a good ground point. Even if you have to cut away some carpet or sand down paint to get to bare metal. You need good ground points for the head unit, amp, and a noise suppressor. The factory head unit ground could be causing the hoise as well. try a different ground for the hed unit, too.
see if it helps.

Bronze Member
Username: Johnny619

San Diego, CA

Post Number: 94
Registered: Dec-05
i think i had that problem before, when i replace my old battery with a new one, when i speed up i hear a nasty noise from my speaker, someone told me to fix my ground on the battery. I reground my chasy ground and the problem when away.

Bronze Member
Username: Johntheguy

Post Number: 38
Registered: Aug-05
is it bad if i got my system installed somewhere and it looks like they just spliced into my rear speaker wires with a LOC (a small box)? if i care about quality and power should i run wires direct from the head unit back to the amp in my trunk?

Silver Member
Username: Mixneffect

Orangevale, Ca. USA

Post Number: 882
Registered: Apr-05
"When I install the Amp, engine noise comes through the speakers "


"How do you get rid of this sound without buying an unwanted aftermarket deck or an RCA conversion kit?

Usually when you have a factory HU, you will have a common ground. The negative speaker wire will common with another wire. Usually with other negative speaker wires. Sometimes with the ground, and sometimes even the antannae.

You noise may be coming due to a short in your wiring circuit, not necessarily your audio wiring to your amp.

New member
Username: Ccarson

Great Lakes USA

Post Number: 3
Registered: Apr-06
Just two cents here. Haven't heard anybody ask this, but how old is the car? If you live where I live, corrosion is a big problem. As most of the guys are recommending, good clean grounds! Most newer cars have a ground distribution system. If the ground that goes to the head unit also is the ground for some other accessories you could also have a wire that has been overloaded at some point. This could cause a resistance change in the wire and creating a ground loop. More than likely it's a dirty ground. After working as an industrial electronics EMI/EMC electromechanical design engineer for a few years I will tell you this. Grounds are not grounds, but rather current returns. Except safety grounds which you won't find any reference to in automotive. Electricity is like water wants the least path of resistance. U need to check the integrity of the charging systems ground (motor to body, battery to body) and the radio circuit as well. I agree to that the amp or the radio itself could be the problem, but less likely.

Another old trick is a transformer coupled isolator (if they still sell them?). Transformers only pass AC. I used to use these to isolate the noise soruce when trouble shooting a system for noise problems years ago. Here again this is just a band aid to the real problem.
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