Noise Noise Noise.... How to kill it

[dieseltwitch]

Been working on my system the last few days, some changes today resulted in a crazy amount of noise.

My goal was to get rid of the head unit.... Mission accomplished. (take a look at the photos at the end and comment, I'm not 100% done but need to clean up the wiring)

Anyways, today i ran the Input RCA's to the front of the truck to hook into a bluetooth speaker adapter I installed in the glove box. long story short that is the primary input for audio into my system, there will be more but this is the primary one. I ran the input RCA's along with the the remote on wire in the floor tray on the passenger side in the door jam, along with the main 4AWG power supply cable. (is this the source of my noise?) Now I get horrible noise... and its defiantly alternator noise. As of right now the input (L/R) RCA's feed into the EQS I have wired in just before the amp. I had things wired loosely before just for testing. now that i have the RCA in the same try as the 4AWG power cable i get horrible almost laughable noise. is this bad place to run them?

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[Staynlean 10+ year member]

Get to testing, I'm confused by your original post about what exactly is going on. Remove current rca's and run them through the cabin, away from whatever area or wires they are currently up against.

Did you make new grounds for anything? Check those too, that's critical. Did you run new, different wires? If so reads with d running straight through cabin to source and see if noise continues.

All grounds are critical so if you changed any or added new ones double check with your meter or make solid grounds.

*Edit, I see you say you ran your power wire in same channel as your RCA cables. This *could very well possibly be the cause of your noise.

First thing I would do is pull the RCA cables out of the channel, away from power wire and see if that clears the noise up. If it does you could attempt to run them together in same channel again, you just might need to wrap the power wire and rca's in loom from the hardware store. If that fails, run rca's to your eq's AWAY from your power wire, i.e. Different route.

 

[dieseltwitch]

Did you make new grounds for anything? Check those too, that's critical. Did you run new, different wires? If so reads with d running straight through cabin to source and see if noise continues.
All grounds are critical so if you changed any or added new ones double check with your meter or make solid grounds.

I was very careful with my primary ground; a 4AWG back to the body near the amp. I cleaned the area of paint and secured it firmly, then covered the ground with with pain to keep any rust out.

I will pull the RCA's out of the tray today. I'm just not sure how else to get them to the front of the truck.

 

[bbeljefe]

You can indeed get alternator noise induced on the signal wires when they're running together but, there shouldn't be that much noise on the power wire in the first place. So, the first thing to do is find out why that noise is so bad and then, fix the problem rather than look for a patch.

Since the noise is almost always from a poor ground, that's where I'd start. You say you have a good ground to the body of the truck but how well is the body of the truck grounded to the engine/alternator? After all, if there's a noise problem coming from the alternator, then that's where you have to go to stop it. The best way to do that is to install the ground portions of a big three upgrade, although installing the entire upgrade would also be a good idea.

Also, the source ground is the reference ground for your audio signal so making sure it is sound is also a must. And when the RCA cables are grounded properly, they tend to reject noise to some degree. Obviously, yours aren't so I would double check that ground and even move it if necessary.

 

[dieseltwitch]

You can indeed get alternator noise induced on the signal wires when they're running together but, there shouldn't be that much noise on the power wire in the first place. So, the first thing to do is find out why that noise is so bad and then, fix the problem rather than look for a patch.
Since the noise is almost always from a poor ground, that's where I'd start. You say you have a good ground to the body of the truck but how well is the body of the truck grounded to the engine/alternator? After all, if there's a noise problem coming from the alternator, then that's where you have to go to stop it. The best way to do that is to install the ground portions of a big three upgrade, although installing the entire upgrade would also be a good idea.

Also, the source ground is the reference ground for your audio signal so making sure it is sound is also a must. And when the RCA cables are grounded properly, they tend to reject noise to some degree. Obviously, yours aren't so I would double check that ground and even move it if necessary.

Ok so I did a little testing. I pulled the RCA's out of the tray and the problem didn't go away. However, I was able to get 90% of it to go away. I should explain that I have a Logitech Bluetooth Speaker adapter normal meant for home audio. I installed a 12V to 5V 3W Power converter to power the BT adapter. I had it grounded separately from the amp. I've now moved the adapter and power supply to the back and tied it into the same power/ground chain that I have the amp and EQS on and that took care of about 50% of the noise. I then unbalanced the inputs on the EQS and isolated the ground for the EQS its self. this took care of another 25% of the noise. I then made my own RCA cables using RG6 Coax cable and Compression RCA Connectors. This took care of the rest.

However, I still have a hiss that i can hear if i put my ear up to the speakers? Will upgrading the "Big 3" get rid of the rest of the hiss?

 

[bbeljefe]

Ok so I did a little testing. I pulled the RCA's out of the tray and the problem didn't go away. However, I was able to get 90% of it to go away. I should explain that I have a Logitech Bluetooth Speaker adapter normal meant for home audio. I installed a 12V to 5V 3W Power converter to power the BT adapter. I had it grounded separately from the amp. I've now moved the adapter and power supply to the back and tied it into the same power/ground chain that I have the amp and EQS on and that took care of about 50% of the noise. I then unbalanced the inputs on the EQS and isolated the ground for the EQS its self. this took care of another 25% of the noise. I then made my own RCA cables using RG6 Coax cable and Compression RCA Connectors. This took care of the rest.
However, I still have a hiss that i can hear if i put my ear up to the speakers? Will upgrading the "Big 3" get rid of the rest of the hiss?

Does the frequency of the hiss change with the RPM or is it constant?

 

[dieseltwitch]

Does the frequency of the hiss change with the RPM or is it constant?

The original noise was very much so! Now it's to soft it's hard to hear over the exhaust and engine noise. However the noise is still there when I just turn the system on with out the engine running... What does this mean? It's still very soft, and I haven't truly matched the levels yet as I don't have all my parts in place. Am I just being picky?

 

[bbeljefe]

The original noise was very much so! Now it's to soft it's hard to hear over the exhaust and engine noise. However the noise is still there when I just turn the system on with out the engine running... What does this mean? It's still very soft, and I haven't truly matched the levels yet as I don't have all my parts in place. Am I just being picky?

Get a recording that has a long silence in it and play it through the blue tooth connection. If it goes away during playback, it could very well be the bt module or the source you're using.

And yes... you're being picky. But who cares? It's your system and you want it to be as good as possible. Sometimes that requires picky. ;-)

 

[dieseltwitch]

Ok deffently alternator noise! Start with the big three?

 

[bbeljefe]

Ok deffently alternator noise! Start with the big three?

That's what I would do.

 

[dieseltwitch]

Just to be clear the big three is;

Main power from alt to battery

Main ground from motor to battery

Main ground from frame/body to battery?

I'm planning on going with a 000 cable to handle a 300amp alt, two #8 ,000 warn winches and my 900W amp

Any special recommendations?

I am noticing some noise that is present when the ignition is off. How do you recommend I clean up the signal coming from my BT module?

 

[dieseltwitch]

Is a ground loop isolator worth looking into? Im noticing that if i crank up the input sensitive on the EQ that the buzzing gets worse. If i disconnect my input all together the noise goes completely away. This makes me think that the noise is coming from the BT device and no where in the rest of my system.

Im still doing the big 3 upgrade anyways

 

[bbeljefe]

Wow... that should be plenty of juice.

And yes, you're correct on the big three. As for the slight noise coming from the bt module, you could use an isolation transformer for that, since nothing else seems to be able to eliminate it. But first, I'd check the cable between the bt and the EQ. I've seen a phono plug be just barely loose and cause noise. You could also try relocating the bt module.

 

[Staynlean 10+ year member]

Hey good job, sounds like you got the majority of it cleaned up I guess? Heck, your one post said that 90% of it was gone man you can't beat that.

I admit, I'm unfamiliar with some of your electrical equipment however I am familiar with electricity. Hope you got some help from your post. Good job.