Ground noise through speakers after new amp install

[ewebz91]

My System:

Speakers:
Phoenix Gold Ti2 Components
Pioneer Coaxial Rear doors (no sure what model, something relatively cheap)

Subs:
2 x Phoenix Gold Ti3 10" 2000wrms
Amps:
4 Channel - Pioneer GM-A6604 - 4awg power wiring
Monoblock - Clarion DPX11500 - 00awg power wiring

LOC - Audiocontrol LC6I - 16awg power wiring.



Everything has a clean ground and is grounded seperately with the subs grounded to the battery, the others to the chassis. But since upgrading from a Pioneer GM-D8601 to the Clarion DPX11500 and upgrading to a higher gauge of wiring, it seems to be sending a buzzing back through the RCAs to the LC6I and into the speakers. We have tested the amp in another car and it did not do the same thing.

The amp seems fine in other cars and if we disconnect the rcas it is fine again. Does anyone know anything else i can check? Running out of ideas.

 

[stockies]

Where is the LC6i grounded?
Is it separate and how short of a ground is it ie: less than 40cm?

I had a similar issue with my LCQ - 1 when I first installed it. I ended up making all amp grounds 0 gauge, even if the power was only 4 gauge, them linking ALL the ground points I used with 6 gauge cable, with an added ground point that was less than 4 inches away. (yes it even goes back to the battery)
Stopped the "factory" ground loop that was happening as the FG's are **** for the feedback hiss noise.

I ended up also putting a "noise suppressor" on the factory power wire for the vehicles ICC (headuit) and factory ground.

My cheap Sony amp with my very "bright" Alpine DD Linear splits was also (and still is) a problem. The amp is built poorly and the speakers and tweeters pick up all sorts of rubbish in the signal due to their design.
However, your Pioneer amp "should" be of better quality.

 

[stockies]

Also: I'm pretty sure I added an extra ground to one of the chassis screws on the LCQ-1

And just to confirm, your subs are grounded to your battery? (i know its in the boot in a VE) but how long is the cables? and do they join together before the battery to make one connection or at the battery?

 

[ewebz91]

The guy who had originally installed the setup had the LC6i connected to the power and ground of the 4 channel amp which was about 10cm. It is now run with power from the battery and grounded to a bolt near the battery, cabling would be more than 40cm. Probably about 60 - 70cm but not too sure.

The sub wiring is pretty short, but the ground is longer than the power (not sure whether that is going to make a difference. Both would be under under a meter.

Everything power wise coming from the battery is off of a different point on the terminal

Not sure what you mean by them joining near the battery? Could you explain?

 

[ewebz91]

The weird thing about it is that the feedback seems to be coming through the RCAs. When they are disconnected from the monoblock it seems fine. So it seems to be going through the RCAs into the LC6i then through to my 4 channel.

I will be installing a head unit eventually and once thats done the LC6i will be gone but thats probably still a while off and its annoying the s**t out of me

 

[stockies]

Where is the speaker wires tapped into for the LC6i?
are they run down the car, next to the power cable for the battery (Passenger side - runs from under the back seat to the engine bay) or the drivers side?

Fault finding questions:
1) what type of speaker wire did you use? (thickness/shielding etc)
2) What type of RCA's are used? Where are said RCA's - I'm assuming the main run of signal is through the speaker cables off the vehicle headunit then the LC6i is in the rear of the car, near the amplifiers.
3) Your ground cable "should" be shorter than your power cable to avoid the dreaded ground loop hiss
4) are you using the LC6i for the remote wire turn on?

And to explain further, due to the factory "ground loop" in my Ford, I found I had to ground both amps within 30cm of the of the amps (separately) then join the two points together with 0 gauge - and then join them into the 6 gauge loom I had running all over the car (grounded at the factory amp in the boot, then again on the parcel shelf factory loom, then again in the passenger kick panel (LCQ-1 is grounded here) with the factory ground point(s) and then, it all heads to the negative point on the battery under the hood.
- every factory ground point I could find in the main harness has another "ground strap" of 6mm cable to the chassis, which is then attached to my Frankenstein ground wire system.

This fixed the amount of feedback hiss in my system, but due to my ICC being so "noisy" because its a heap of unshielded crap - I still have some white noise at low levels, It was at this point I gave up. Changing the amp to a better product will help me - but until it overheats and cooks, I'm never going to bother.
I admit, I did rope one of the older radio tech guys at work to break out his oscilloscope and check out how bad the "white noise" was, because I was extremely frustrated with it. Without the Oscilloscope - I'd have have never gone as far as I did to fix it.

But the morale of the story is, Holden/Ford/Toyota/BMW/Audi etc always scrimp on the ground circuit of their vehicles. With an added 3m of cable, properly grounded in each vehicle - these issues would be non existent.

 

[ewebz91]

Yeah i already went over a fair bit of the cabling to try and figure it out.
All the speaker wiring is run from the back of the headunit down the drivers side of the car

1) Using 16awg from the back of the headunit to the LC6i then from amp to speakers, Subs are running 10awg. Both have a thick shielding on and good actual cable thickness aswell.
2) I am using stinger rcas from autobarn, tbh they don't have a lot of shielding on them but i have not run them near any power.
3) I will try swapping them around and seeing if that gets rid of the noise. Could very well be the issue
4) LC6i is being used for remote turn on, but there is another remote wire the guy who did it ran during the install that could be utilized, not sure what he ran it from though, its just sitting in the back taped off.

To be honest i hadn't really has an issue up until the installation of this new amp. I could not hear any unusual noises coming through the system at all. That being said i was not really listening that closely. But i suppose that going from an amp that was putting out a maximum of 800wrms to an amp doing almost double that and 00awg wiring was bound to find one issue or another.

When i get home i will go back over all to and from the LC6i just to make sure theres nothing stupid ive missed.

 

[stockies]

I'm pretty sure mine are Stinger RCA's, but they are the "Crystal" series ones. The shielding on them is pretty good, However you do only get what you pay for when it comes to RCA's.
Mine are run down the centre of the car, since theres not factory looms with power there to interrupt the signal.
Another trick is to cover them in split conduit (entire run) as the plastic acts as other "shield" against the other wires electromagnetic fields.

I found with the LCQ-1 there was more noise introduced into the mix (found with the Oscilloscope) when I used the remote turn on wire. Unfortunately theres no wire in the FG's that is live with the ICC and works until the doors are opened, that isn't 5v. If there was, I would't have bothered with an LOC and just wired it all up a better subwoofer separately.

I'm starting to think your amp might be an issue, since you never noticed it before, or that its too powerful and not matched right to your front splits...
Bigger power doesn't always mean "cleaner" power to your speakers. This may be an example of this. How high are your gains set on the amp, because from memory - theres not much "tuning" that can be done with the signal from the LC6i.... which is the reason I went for the LCQ-1

Try "turning down" the input dial on the LC6i a little bit, take a photo of the current settings first, so you know where to put it back to if it doesn't change anything.
Then turn up the gain on the amp, hopefully there's a combination of this that eliminates most of the noise. I'm sure you've tried this however - I'm just writing it incase you just threw in the new amp and didn't tune the system for it.

Have you still got the original amp? If you still do, install it back again and see if the problem is still there...
Borrow a mates amp (if he'll let you) if you still don't.

After all that, It may be time to look at upgrading the power wire from the battery to the alternator....


Oh, and stupid question, but I assume that with all that 00 gauge wiring you installed, theres a ground strap from the battery negative to the car body earth nearby?

 

[stockies]

Oh, and for reference, my LCQ-1 is connected as such:
Power - same circuit as the ICC constant power - and with a noise suppressor that "interrupts" or "breaks" the connection and has its own independent ground (which is then added into the Frankenstein 6mm ground circuit) has a 5 amp fuse
Accessories - comes from the cigarette lighter - 2 amp fuse
Ground - to independent ground, that is then attached to Frankenstein circuit running all over the car. There is also a 16 gauge wire to the bottom left screw of the units cover with a small ring terminal that is connected to the ground terminal on the LCQ-1.

The ground circuit is as added to the factory two earths for the ICC for good measure.

I have duel wall heat shrink on these wires (about 2 inches worth) for added shielding (shielding on these cables is pretty good anyway) then the ends are solder "tinned" for a better connection into the LCQ-1 screw terminals.

Yeah, I know OCD much?
But thats how bad I wanted to get rid of the ground loop. If I can find some photos of the Frankenstein ground circuit I'll post them up.

EDIT: Ohhh I just remembered, under the metal cover of the LC6i, is there those little switches? so you can tell the unit its connected different ways? Mine has one for the ground circuit, and I also moved it off the "factory" or "shipped" setting and that helped heaps!

 

[ewebz91]

Oh, and for reference, my LCQ-1 is connected as such:
Power - same circuit as the ICC constant power - and with a noise suppressor that "interrupts" or "breaks" the connection and has its own independent ground (which is then added into the Frankenstein 6mm ground circuit) has a 5 amp fuse
Accessories - comes from the cigarette lighter - 2 amp fuse
Ground - to independent ground, that is then attached to Frankenstein circuit running all over the car. There is also a 16 gauge wire to the bottom left screw of the units cover with a small ring terminal that is connected to the ground terminal on the LCQ-1.

The ground circuit is as added to the factory two earths for the ICC for good measure.

I have duel wall heat shrink on these wires (about 2 inches worth) for added shielding (shielding on these cables is pretty good anyway) then the ends are solder "tinned" for a better connection into the LCQ-1 screw terminals.

Yeah, I know OCD much?
But thats how bad I wanted to get rid of the ground loop. If I can find some photos of the Frankenstein ground circuit I'll post them up.

EDIT: Ohhh I just remembered, under the metal cover of the LC6i, is there those little switches? so you can tell the unit its connected different ways? Mine has one for the ground circuit, and I also moved it off the "factory" or "shipped" setting and that helped heaps!

I thought it had something like that jumper thing!!!! Got around to looking at it today, changed that to grounded instead of isolated, changed the wiring around and did a bit of tidying and rerouting of certain cables (it was a bit of a mess). Tested it out and there is no more noise!!!

Not sure which of these did the trick but at the end of the day it's gone and I'm happy!

Appreciate your help mate!