Killing GPU EMI On New Powered Monitors

Hello, person reading this. I have an issue I hope you can help with.

I recently purchased the Monoprice 5 Inch Studio Monitors and Subwoofer for use on my PC. Under desktop usage the system is very nearly noise free, but when the GPU is being utilized heavily, such as in a game, I get a buzz/hum which changes based on frame rate and what’s going on in the game.

In the past I have used a stereo receiver, an old creative 5.1 system, and headphones though the rear 3.5mm interface without issues.

As experiments I have connected the input of the speakers to my Samson Go Mic’s headphone jack (did not help), fully disconnected the speakers from any input (noise not present when in game, so it’s not picking it up through the air), and moved my GPU to the next available PCI-E slot on the motherboard (did not help).

I would have thought when I had them connected to the Samson mic it would have totally isolated the input from the GPU as the mic is connected via USB, but obviously it’s bleeding into my USB somehow.

I essentially have two questions, why is this happening and how can I avoid it going forward?

Maybe relevant system specs.
CPU: [email protected]
Mobo: ASUS X99 Sabertooth
GPU: XFX Fury-X
PSU: Corsair RM850
OS: Windows 7 Pro

Sounds like coil whine on the GPU is shooting out EMI like you said that is why frame rate effects it but it is being picked up by the rest of the mother board and being passed into everything. coil while is come part of the GPU circuity switching on and off at the frame rate so a menu hitting the hundreds or thousands of FPS will make a racket. Some Fury's were known to be pretty noisy electrically.

The receiver you were using before probably was good and isolated circuitry wise so it just filtered it out and gave you the clean sound. It was likely still getting the noise but cleaning it up.

Does it quiet down at a stable 60hz or whatever you monitor runs at. Try turning on Vsync in a game you know makes this happen and see if it stops it or helps at all.

I am no wizard at all. But it sounds like a grounding issue there after. Someone will definitely know more than me.

Groundloop

Isolate power and it will stop.

How does it work? Trace back to the point where the ground of the speakers and the ground of the PC come together, then connect one of them to a different grid point. If that doesn't help, you need filtering, sometimes a simple LC network suffices, sometimes something as dumb as a ferrite ring suffices, sometimes nothing works but isolated DC-DC conversion.

1 Like

Thank you for the input both of you. Another thing that may be part of it is I'm using an unbalanced input from the PC to the speakers (a 1/8th TRS to two 1/4th TS cable). This is the only setup in which the speaker system has had an independant ground, so I guess that could be creating a problem.

I will also try turning down the volume on the speakers and raising the signal level from the PC. Listening volume was around 10% of the windows volume.

If your still running into problems after the ground loop fix I would suggest getting an external dac like this one.

Then you will need to buy a spidif cable it fixed my issue with my jbl lsr 305. What this will do will take all of your audio processing that was originally done on the motherboard and move it away from the computer which reduces case noise and other audio feed back issues. Then at least on my setup I cranked the volume all the way to max on my computer and speakers and control it from the dial on my preamp.

I turned the gain on the speakers way down and turned the windows volume up to get the desired level of volume. The buzz sound in game is not entirely gone, but at this point it's hard to differentiate between the coil whine coming from the GPU itself and the speakers. Sorry for what feels like a goose chase. Maybe this thread will help someone in the future.