ALT noise in new install, I don't know what do to?

[XORstatus 10+ year member]

I have just upgraded from a factory HU to a aftermarket 4 channel amp.

The amp is an MTX TC4004, the speakers are newish.

The noise happens when I use my new EQUALIZER.

If i bypass the EQ and run the line out converter directly to my MTX amp the noise IS GONE!!

BUT the EQ has an alternator noise and a sort of STATIC noise, the alt noise increases when the engine revs.

Initially I thought that this could be a Grounding issue, so I changed the ground and a proportion of the problem ceased, HOWEVER the noise is still audible at low volumes and the static, white, background noise is audible at times AND in between songs.

What do you guys think? THIS ONE IS BEYOND ME!!!

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[brodeisel 10+ year member]

ground the rcas

 

[LUV2BHATED 10+ year member]

try grounding the rca's

 

[Vossy 10+ year member]

ground the rcas

That's where I'd start

 

[XORstatus 10+ year member]

SO the assumption is that the EQ is not the problem but the RCA's are the problem?

Even when eliminating the EQ solves this problem?

 

[Moble Enclosurs 10+ year member]

The LOC has its own gain settings in some cases, so there is an increased sensitivity from the LOC as well. LOCs are known to cause noise problems, and should have its own ground for that reason. Do you have the LOC ground connected to the same ground location as the amplifier or HU? This might be part of the problem. But as everyone has mentioned so far, it is highly likely a ground issue in the system due to the engine noise. Two parts exist...the engine noise/alternator noise and then static noise. The static noise can be controlled by setting the gains properly in most cases due to the mentioned sensitivity increase. You may notice that if an external music player is connected, that this gets louder as well, for the same reason of another low level input being added. Best way to control it is grounding everything independantly, and setting the gains properly. Do not have the LOC gain match all the way up. This increases any noise and distortion from the HU significantly. Hope that helps!

 

[Moble Enclosurs 10+ year member]

SO the assumption is that the EQ is not the problem but the RCA's are the problem?
Even when eliminating the EQ solves this problem?

Because the EQ acts as a gain also. Its all about keeping the low level input matched to the HU ouput as close as possible, and by adding more and more components parallel with each other, they all aid the same circuit and its final output to the load/speakers before the signal is phased back into the rest of the circuit. The speakers are passive to any noise/sound in the system because that is what it is designed for. So, any electrical noise levels sensitive enough to be heard, are passed through the loudspeaker. So, in this case, yes by losing a components added input electrically, you lower the noise levels significantly this way also. It is all about gain matching and grounding in your case I would imagine.

 

[maylar 10+ year member]

If the EQ is connected with no input (no LOC) do you still get noise? If yes then the problem is likely the grounds around the EQ and the amp.