# Help: White noise issues



## HurikaneDrew (Jul 7, 2014)

I'll start by saying that everything is grounded to the battery yet I still get white noise at no volume and the white noise doesn't change with volume it just becomes a faint background noise. It goes away when I turn the head unit off which turns off the amp also when I disconnect the RCAs or disconnect the speaker wires from amp it goes away. I haven't pulled RCAs from the headunit yet to see if thats the source. Again I have a Kenwood Exceleon DDX8901HD. The white noise only comes from my tweeters, I have two sets of Infinity Kappa Perfect 6.1s. I think it could be the RCA preouts on my headunit, the GMOS-044 harness could be too high current, my headunit has 5v preouts and my Infinity Kappa Four amp has a max input of 6v, or the RCA inputs on my amp could be faulty? Any other ideas? Things I want to try are 1. Ground the frame of headunit where RCAs plug in to chassis 
2. Check RCAs on both sources(unplug from amp or unplug from headunit) 
3. Set gains with headunit at Max volume considering it has 5v preouts and my amp is sensitive to 6v 
4. Make sure all harness wiring/wires and components are away from other electrical components in car
I'm not sure where to go from here.
I forgot to mention I used to have the high level input wires from harness to headunit connected and since I disconnected them the noise presented itself but I think that was only because it masked it when they were connected. This leads me to believe it has something to do with the OnStar retention portion of the GMOS-044 harness or the harness in general. I was looking at the LC-GMRC-044 harness which fits my Cruze and looks a lot more simplistic and has everything I need just no OnStar. Except its another 60$...


----------



## hificruzer226 (Mar 27, 2013)

Its in the headunit and your amp.... Your stereo is only as good as its weakest link. 
Your gains is where you are causing the most of the noise. FYI I have only been able to see 1.7V on the low level with 1khz tone on those units... They will never hit 5v. Turn your gains down, your noise will will mimic that.


----------



## ChevyGuy (Dec 13, 2014)

I think you have your amps cranked up too high. They're amplifying the small amount of white noise that's always there. I'd turn down the amps until the white noise isn't a problem.


----------



## pikeintheboat (Jun 8, 2015)

If I could guess, it is probably the headunit generating the noise. The noise begins there and is "amplified" by the other amplifier which is driving the tweeters, thus making it louder. I don't think you have "motor noise" or any other induced current on your low level inputs. It that was the case, you could wrap a ferrite bead around it and suppress the common mode current. I would hook the tweeters up to a high level input to see if the noise goes away (since they don't need that much power anyhow). Do you hear any hiss at all coming from the mids/subs, even if it it really quiet?


----------



## HurikaneDrew (Jul 7, 2014)

No hiss coming from the mids all though I didn't put my ear right up to them. I hear it from the tweeters mainly, I will have to put my ear up to the mids to double check. I used my DMM to set my gain at 20v for 100rms to each channel. My amp can provide 125rms x 4 supposedly at 0.05% THD so I don't feel like the white noise makes any sense. I forgot to mention I had a minor buzzing noise when my headlights come on at night or if I turn my dial to put them on manuallh, I made that buzz much quieter when I realized that when mounting my amp in the trunk a couple of the screws were long enough to touch the chassis under the carpet. I took the screws out and my amp isn't mounted as of now but it helped so much that I can only hear a faint buzz at no volume when getting very close to the tweeter. The white noise is still persistent, not as staticy after unmounting the amp but I still feel as though something is off. Before unmounting amp I would put my headunit in stand by mode and still hear a white noise. After unmounting my amp if I put my headunit in standby I get complete silence, no more white noise but as soon as I select a source to play music from it comes back. So I'm not sure if its the headunit. My amp says it can handle a Max input of 6v from preouts my Kenwood headunit advertises 5v preouts and I'm not sure they actually even reach 5v to be honest.


----------



## ChevyGuy (Dec 13, 2014)

All amps create hiss. That's completely normal. What isn't normal is to have it loud enough that it's noticeable. 

In this case, it appears the hiss is coming from your head unit. But you've got your amp cranked up so high that you're hearing it. (Or possibly you have the amp itself cranked up so high you're hearing the first stage of the amp or loc.) 

Either way, the solution is to turn down the amp and turn up the head unit. This may reduce the maximum volume you get with the head unit turned up all the way, but you have to make your choice as to what bothers you more. As long as the hiss isn't noticeable in a normal listening position, I wouldn't worry about it.

Again, hiss comes from amplifiers amplifying. It doesn't come from ground loops, bad connections or the usual causes of hum, static, or distortion. All you can do is re-balance the levels so none of the amps are trying so hard.


----------



## HurikaneDrew (Jul 7, 2014)

Okay well I'm returning the radio and getting it replaced for now I will use my pac AAGM44, could you help me with the wiring for that? I'm so confused
There is a black wire on the input and output then I have the blue/black wire which are all supposedly for ground.. can I splice the pac into itself for ground and only use the white/black negative for common audio signal ground and keep all positive connected? I'm not using the factory speaker wiring I ran my own wires directly to the amp so I'm not sure how to do this with RCAs coming from the amp
I will be using my factory radio


----------



## ChevyGuy (Dec 13, 2014)

I haven't played with that myself. I just know general audio.


----------



## HurikaneDrew (Jul 7, 2014)

As soon as they receive my old radio they are sending me the Pioneer DEH-80PRS and a pair of Focal 690CA1 6x9s to compensate for cost of my original radio considering I didn't want a replacement. Hopefully this will help a little.. I also replaced the power distributor plate hooked to my positive battery terminal, I had a blown fuse and car wouldn't start. That should be a major help too I've already noticed my car running better.


----------



## pikeintheboat (Jun 8, 2015)

HurikaneDrew said:


> Okay well I'm returning the radio and getting it replaced for now I will use my pac AAGM44, could you help me with the wiring for that? I'm so confused
> There is a black wire on the input and output then I have the blue/black wire which are all supposedly for ground.. can I splice the pac into itself for ground and only use the white/black negative for common audio signal ground and keep all positive connected? I'm not using the factory speaker wiring I ran my own wires directly to the amp so I'm not sure how to do this with RCAs coming from the amp
> I will be using my factory radio


General question. Were you using you PAC with the aftermarket head unit?



HurikaneDrew said:


> Okay well I'm returning the radio and getting it replaced for now I will use my pac AAGM44, could you help me with the wiring for that? I'm so confused
> There is a black wire on the input and output then I have the blue/black wire which are all supposedly for ground.. can I splice the pac into itself for ground and only use the white/black negative for common audio signal ground and keep all positive connected? I'm not using the factory speaker wiring I ran my own wires directly to the amp so I'm not sure how to do this with RCAs coming from the amp
> I will be using my factory radio



And, no, you can't wire the PAC into itself. The "ground" needs to be connected to the same ground lug as the headunit. Then there will be no ground loops.


----------



## KENSTV123 (Sep 21, 2014)

Lots of info on here and elsewhere on the pac44, both black wires go to ground of the pac and connect to the same circuit board trace inside, and yes you must use the same ground as the radio-note the ground is only used for the remote turn on BUT a ground loop can develop on the amp side between the amp ground and pac ground at the radio-depends on the amp how isolated the rca's are-if a problem, do not ground the black at the radio and let the pac remote circuit pull ground back from the amp and add a diode on the positive lead of the pac44, also note--do not put the pac44 anywhere but to the right of the radio on top of the glove box or it WILL pick up noise from all the digital signals in the car wiring, and cutting the pac44 harness is the best way to use it with the amp running all the speakers, instructions on the pac44 are confusing at the least !!


----------



## pikeintheboat (Jun 8, 2015)

KENSTV123 said:


> Lots of info on here and elsewhere on the pac44, both black wires go to ground of the pac and connect to the same circuit board trace inside, and yes you must use the same ground as the radio-note the ground is only used for the remote turn on BUT a ground loop can develop on the amp side between the amp ground and pac ground at the radio-depends on the amp how isolated the rca's are-if a problem, do not ground the black at the radio and let the pac remote circuit pull ground back from the amp and add a diode on the positive lead of the pac44, also note--do not put the pac44 anywhere but to the right of the radio on top of the glove box or it WILL pick up noise from all the digital signals in the car wiring, and cutting the pac44 harness is the best way to use it with the amp running all the speakers, instructions on the pac44 are confusing at the least !!



Good tips, but why place a diode on the positive lead of the Pac44? Are you trying to suppress noise or block reverse current? Will any diode do? I think a pic and some part numbers will help our poster. It may be best to just locate the pac as far away from the dash as possible to get away from the processors and 2.4 ghz bluetooth. A common mode choke filter would be a better choice for induced noise from motors and other interference. One ferrite bead wrapped around the positive and negative lead a few times will do the trick. I think you can still get them at Radio Shack and definitely on ebay.

https://en.wikipedia.org/wiki/Ferrite_bead 

And, for ground loops. If you are adding an amplifier to a system with multiple amplifiers, the best way to avoid a ground loop is to have a "common" point of ground for all amps, headunits, processors, PAC44's, and anything else you plan on integrating into the car. The less you rely on multiple body ground-points the better off you will be in "noise" control for car audio.


----------



## HurikaneDrew (Jul 7, 2014)

The only splicing I did was my remote wire from my amp to pin #43 coming out of the oem side of harness. I have the high level speaker plugged into the output of the pac with switch set to rca and my rcas plugged into the input of the pac with switch set to wire. I have not noticed any kind of noise at all not even with the headlights on or my foot on the brake. I don't know how this works but it does.


----------



## pikeintheboat (Jun 8, 2015)

HurikaneDrew said:


> The only splicing I did was my remote wire from my amp to pin #43 coming out of the oem side of harness. I have the high level speaker plugged into the output of the pac with switch set to rca and my rcas plugged into the input of the pac with switch set to wire. I have not noticed any kind of noise at all not even with the headlights on or my foot on the brake. I don't know how this works but it does.


If I have read your message correctly, it sounds like the switches are backwards. Is that what you are saying?


----------



## HurikaneDrew (Jul 7, 2014)

Yes and according to other people the harnesses are backwards as well. I then realized the black wire or optional ground from the RCAs was missing. I must've accidentally pulled it out during install. Long story short I switched the harnesses (wired to input and rca to output with switches set accordingly) and got the same results. Except if I switch the wired side switch of the pac to RCA music gets noticeably louder but more distorted. I'm assuming that's because of the bad quality rcas the pac comes with. I get a buzz whenever the headlights are on at that point. With the switches set correctly I can barely pick up the buzz even with my ear right next to tweeters. This is all so confusing and I really would like to think that the Metra Low Current GMRC 44 wouldn't have this issue considering its for a low current system aka the Cruze.
Could I run a ground wire say 16awg from amp negative to where the pac44/radio grounds, would that help?


----------

