Can't get rid of electrical noise

[Sguirrelfeather]

For a friend's car on which I just finished the install.

2011 Kia Sorento.

Pioneer AVH-491BHS headunit running in active mode

Two CT Sounds T-300.2 amps: one for mids, one for tweets

One CT Sounds T-2500.1 monoblock for aubs

Massive CT2 Tweets

SSA Evil 6.5 mids

Phoenix Gold Elite 12's

AGM up front and back

Apex 320 amp alternator

Big 3 and all runs done with 2/0 cable

One common ground point for all amps which is straight to rear battery which is also connected straight to front battery. Zero ground modulation with the single point ground.

Replaced his crappy RCA cables with quality shielded RCAs. This took care of about 50% of the whining. He installed some sort of filter behind the tweets (these were the noisiest) and that took care of another 25%. I wrapped the RCA connections on the back of the HU with copper wire and attached to the case. This took care of about half of what was left. So, this leaves me with about 12.5% of the original level. Much better, but still VERY noticeable when no music is playing. I followed the directions on this website and I've tried everything except for grounding the HU chassis straight to the battery. FYI, no noise whatsoever with RCAs disconnected from the amps. Noise with them connected, but very little now that I put in the better cables. Noise is reduced when connected to HU. Reduced even more with the wire I installed around RCA jacks. Other than the filter, nothing else I've tried has reduced noise.

Also, I'm not sure if it's alternator whine or ignition related.

I will definitely try grounding the HU to the battery, but what else would you suggest I try if that doesn't work?

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[Boomin_tahoe 5,000+ posts]

Ground loop noise. Have you tried 2 diff grounds for amps instead of one?

 

[Sguirrelfeather]

I have not, but would it make much of a difference? As is, he has 6 inches or so of 2/0 wire to a terminal, and from the terminal there are three wires, one for each amp. Could taking that 6 inches away really make a difference?

And I may have an an epiphany....I think. lol Ground loops are caused by the difference in resistance from the multiple grounding points, correct? Or something like that. Well, with the amps being grounded to the the AGM in back, and the HU being grounded to the car's stock wiring harness, I would imagine that could created a considerable difference. So I should maybe try grounding the HU to the rear AGM instead?

 

[SubbinNCali 10+ year member]

Doubt grounding to the rear it would make a difference (unless your agm battery up front is toast), but try it anyway for your own sanity. Have you tried using your phone as the source plugged into the RCAs of the amp yet? With engine on and off?

 

[Boomin_tahoe 5,000+ posts]

Ground loop is multiple grounds in 1 spot. That's why people prefer to have them spread out.

 

[Boominburban]

nvr mind ....

 

[dbjunior 10+ year member]

Noise can be introduced by another electronic in the vehicle. In my girls truck the fans on the led headlights caused noise and in my truck the heat/ac blower motor caused noise. Its induced into the headunit threw the power wires. These issues where fixed by putting circular magnets around the power wires. They are two piece and clamp around the wire.

 

[Papermaker85 5,000+ posts]

Ground loop is multiple grounds in 1 spot. That's why people prefer to have them spread out.

No

 

[Papermaker85 5,000+ posts]

Noise can be introduced by another electronic in the vehicle. In my girls truck the fans on the led headlights caused noise and in my truck the heat/ac blower motor caused noise. Its induced into the headunit threw the power wires. These issues where fixed by putting circular magnets around the power wires. They are two piece and clamp around the wire.

Caps are great filters

 

[Sguirrelfeather]

He's on a trip right now, so when he gets back I'll try the re-grounding of the HU and consider torroidal magnets. Caps are an option as well I suppose.

 

[Papermaker85 5,000+ posts]

He's on a trip right now, so when he gets back I'll try the re-grounding of the HU and consider torroidal magnets. Caps are an option as well I suppose.

Move your rca. Reground

 

[Jcsaudio]

Also you might want to check to see if the amplifier is screwed to the metal chassis or not. If it is than you may want to isolate the metal body of the amplifier from the metal chassis of the car. Some amplifier manufacturers state this in their oeners manuals.

 

[audiobaun 5,000+ posts]

think that the PICO FUSE is blown in that Pioneer HU. If you hot swapped any RCAs then more than likely you have blown that PICO FUSE.Pioneer HUs are natorious for this issue..Thats why Ive stuck with Kenwoods lately, as I swapp amp constantly.

 

[Sguirrelfeather]

Move your rca. Reground

RCA already moved twice. Reground where? It's going straight from amp to a single isolated terminal, and then 6 inches to the battery...and that battery is going straight to the other battery.

Also you might want to check to see if the amplifier is screwed to the metal chassis or not. If it is than you may want to isolate the metal body of the amplifier from the metal chassis of the car. Some amplifier manufacturers state this in their oeners manuals.

Mounted on wood, so I know that's not the issue.

think that the PICO FUSE is blown in that Pioneer HU. If you hot swapped any RCAs then more than likely you have blown that PICO FUSE.Pioneer HUs are natorious for this issue..Thats why Ive stuck with Kenwoods lately, as I swapp amp constantly.

Now THIS has me curious!!! I've never heard of the pico fuse. I'll have to check it out.

 

[Sguirrelfeather]

Just read up on it and saw some of the fixes. Most said my method of wrapping the RCA outs will solve it....and when I looked at the fuse repair pics I realized I may NOT have actually grounded the wrap I did. The screw I used looks like it may not be electrically connected to the case, but to a plastic insert which is attached to the PCB. OOPS!!! Well, learned something new! Several things, actually. lol