Help! High pitch ringing noise!

**soundman98** · 02-23-2011, 07:51 PM

i was hoping you guys would search

-- there is tons of info on GL's, and how to fix them.

nivanov is correct on grounding the motherboard-- many times the motherboard is correctly grounded through the 20/24 pin connector, so physically grounding the motherboard could cause multiple ground paths-- which is a good definition for what ground loops are..

i have occasionally read of certain onboard sound cards not sharing the same ground plane as the rest of the board--where the designers expected the metal pc case to be used as the connection, so motherboard grounding would be required in this case.. but the creative x-fi you have 'should' use the shield of the usb cable for a common ground..

many times GL's are caused by poor/dirty/incorrect connections. this could be on either the power or ground side, but the ground connection is the one that will cause the most amount of problems because it is the one that everyone neglects the most..

where did you attach your pc ground? did you sand the paint off? are there any other devices that share that same ground?

**knownchild** · 02-23-2011, 08:49 PM

I used a 10 gauge wire for my 12v line and a 14 gauge wire for the ground, could this cause a ground loop? or not a good ground?

**soundman98** · 02-23-2011, 09:12 PM

that is a good start. your ground should always be at least the same gauge, or larger then the positive power wire. and did you sand the paint off the ground connection point?

**knownchild** · 02-23-2011, 10:24 PM

sure did

**soundman98** · 02-23-2011, 10:42 PM

ok, sometimes when you share a ground with some factory devices, it can cause a GL, or if your amp has a different ground point then your carpc, that can also cause a GL.

**knownchild** · 02-24-2011, 08:18 AM

I read up on the whole ground loops and what can cause them. I have my carputer which is grounded to the front passenger side of my car frame, my head unit (i use this as an amp for now) and my Viper remote start which is grounded on the drivers side part of the cars frame.

Im sure all three of these device being grounded in different areas may be causing the ground loop, thing is if all devices are properly grounded and i isolate the device(s) which is causing the loop will grounding it in a different area of the vehicle make a difference? or should i make them all have the same ground?

**soundman98** · 02-24-2011, 04:38 PM

non-audio devices can sometimes affect audio devices, and cause a ground loop when connected to the same point.

to prevent that, just try connecting the radio, and carpc ground together.

**knownchild** · 02-24-2011, 05:51 PM

So can i drill a hole right next to the PC's ground instead of using the same hole? without it creating a loop?

**soundman98** · 02-24-2011, 07:10 PM

sometimes.. and sometimes not..

it would be better to use the same bolt if possible.

**kegobeer** · 02-24-2011, 07:21 PM

There are a lot of things to consider when it comes to getting rid of induced noise. Location of the equipment, proximity to power wires and equipment, and poor grounds are just a few of them. I eliminated 95% of the noise I got by moving my amp and computer from the shelf above my gas tank in the trunk (right above a very noisy fuel pump) to an amp rack I built and put in the base of the trunk, and by using a distribution block for all of the equipment grounds that connects to a good chasis ground by a 4GA wire (I already had a power distribution block for the equipment). The rest was eliminated by grounding the RCA cables at my USB DAC to the same ground distribution block.

Moving the computer to a different location, using a different ground, and grounding the RCA cables at the computer are things you can try.