Question At wit's end - GPU Speaker Buzz

drewp29

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Jan 7, 2009
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So I'm seriously at wit's end here.

The problem I'm dealing with is GPU induced buzzing in my home theater speakers. It is not coil wine.

To be fair, I am running a fairly complex system, and I dealt with some ground loop issues between the equipment early on that have since been resolved.

My system consists of the following:

HTPC Gaming Rig - I7 4790k (stock / no OC) cooled by Corsair H100i Pro, Gigabyte GTX1080 Windforce, 16GB Crucial Ballistix Sport VLP RAM, Samsung 500GB SSD, Thermaltake Core G3 case, Seasonic Focus SGX-650 PSU, ASUS Maximus VI Hero - Z87 MB

Windows 7 Pro Ultimate x64

Television - LG 65" OLED

Now for the complex part:

Speakers: 7.1 Surround Sound - Custom built fully active 3-way Left/Center/Right Speakers, (1) lilmike's Cinema F20 horn subwoofer, (1) dual opposed 20 cubic foot 15in Woofer sub tuned to ~11Hz (for the low-lows, lol), Dayton Audio B652 AIRs for back and side speakers.

Signal chain - PC HDMI Out --> Marantz SR5010 receiver --> Speaker DSP / Subwoofer DSP units --> Various Amplifiers as outlined below

The Marantz Left/Center/Right Preamp RCA Outs go to an Ashly Audio ne24.24m for DSP. The Ashly takes (3) inputs and outputs (9) signals to the amplifiers.

(7) outputs on the Ashly go to a Crown CTs 8200 for amplification of the Left Tweeter/Midrange, Right Tweeter/Midrange, and Center Tweeter/Midrange/Woofer

The remaining (2) outputs from the Ashly go to a Crown XLS 1502 for amplification of the Left and Right Speaker Woofers

The respective amplifiers are all wired appropriately to the Left/Center/Right speakers - I've been running them for about 5 months now.

The Marantz Receiver's Subwoofer output goes to a MiniDSP 2x4HD unit for DSP and then to a QSC PLX3002 amplifier for the (2) subs.

The system sounds very good, though I am changing out the Midrange drivers in the next couple days - not for this issue, for an unrelated sound quality upgrade.

The issue is the same as about a hundred or more internet forum threads - I have buzzing through the speakers when the GPU is active. The intensity of the buzz is greater when the GPU is heavily loaded. I also have the USB mouse scroll buzz.

When listening to music there is no buzzing.

When using KODI to watch movies, the buzzing starts fairly hot as the GPU ramps up (4k takes some power), but decreases when the GPU hits a semi steady state, and is at a low enough level that it is only audible during extremely quiet scenes.

Games are not playable. Rendering 4k even with V-Sync on taxes the GPU enough that the buzz is always present and so bad that you think you kicked a hornet nest.

The PS4 Pro over HDMI is however, dead silent with zero buzzing whatsoever. The Switch over HDMI is also silent.

I also have a perhaps related, perhaps not, issue with speaker pops and clicks anytime a major power draw happens in the house, e.g. HVAC, Stove burners and oven, fan in the back bedroom, light switch in the living room, etc. This happens even with the PS4 and Switch, so may be unrelated.

Things I've tried to fix the buzzing issue:

My PC was originally in a Corsair Obsidian case running an OCZ 1000W PSU. Fearing it was the PSU, and wanting to downsize the case anway, I replaced both with the TT G30 and the Seasonic PSU.

Thinking it may be ground loop related, I rewired my RCA outputs from the Marantz to the Ashly DSP to the commonly accepted as correct unbalanced RCA to balanced phoenix plug per the Rane Audio wiring diagrams.

I have removed and reinstalled every device driver imaginable.

I switched my HDMI cable to an optical HDMI thinking it may be like going to optical SPDIF. I think the optical HDMI still has a ground connection end-to-end though, unlike SPDIF.

I have swapped every power cable and every interconnect in the system.

I have every electrical item on (2) big boy UPS units, both plugged into the same circuit. I plugged them into separate circuits and the problem persisted, plus my ground loop hum came back. I plugged just the PC into a different circuit with the same results.

I have a ground strap between the cases of every component in the system except the PC. This eliminated the aforementioned ground loop in conjunction with the UPS units being on the same circuit.

I have turned off various BIOS options, namely EIST and anything that throttles power based upon the advice from another thread that suggested that the ramping up and down of power draw may be causing a feedback loop.

Turned on/off V-sync in games and globally in the Nvidia Manager.

Changed Windows audio resolution/bit rate to every option available - 16-bit, 24-bit, 44.1 kHz, 48Khz, 96 kHz, 192kHz, etc.

Tried different combinations of power plugs in the two UPS units.

Tested the wall circuits - they are wired correctly.

Things I did last night that I have not had a chance to check:

After making sure the screws were tight from the GFX card bracket to the card, I ran a ground wire from the bracket to one of the motherboard screws. I was careful not to scratch the motherboard and made sure I didn't have any errant wire strands protruding around the screw head. I wouldn't want to scratch a trace and end up killing the MB.

I unplugged the HD audio from the MB, since it runs directly underneath the GFX card, just to rule out interference from it.

I replaced all the black oxide (possibly painted or black chrome) MB screws that came with the case with chrome (or zinc plated) MB screws in case they weren't conductive enough to ground the board properly. The previous case had the same issue, maybe not as profound, but it did, and all those screws were chrome.

I also ran a ground wire from one of the other MB screws to the case. I scratched off the paint so it should be making a solid connection.

The reason I did not verify results is it was super late (like 4:30am) and I had to be to work by 8:30am. I had DDU'd the GFX drivers and updated them prior to running the ground wires. I checked after the driver update and the buzz was still present, but only had the machine on for about 5 minutes. When I turned the machine on after running the ground wires, I did some quick checks, and thought it might be better on videos, but before I could start up DOOM, the screen blacked out on me. I unplugged and plugged back in the HDMI cable, and the screen came on. I fooled with it a little bit more and it blacked out again. Unplugged/plugged and checked GFX card and CPU temps and they were totally fine.

So I didn't have time to mess with it, but I think I need to roll back the GFX card driver. I am also going to reset the BIOS to default just in case I turned something off in there that is causing issues. Hopefully that solves the blackout issue, and I didn't bork something when I ran the ground wires.

Things I plan on doing if the above did not actually work:


Run optical SPDIF from the MB audio. This is a temp fix. Optical only supports 5.1 channel audio, and I want the full 7.1 my system is set up for.

Replace the Motherboard. As much as I don't want to replace parts of an aging system, it currently runs everything I throw at it in 4K on Ultra or near Ultra settings. I figure I'm good for a couple years until the PS5 and Series X are being utilized to their potential, and then I might need to upgrade.

Any thoughts? Thanks for reading if you made it this far!
 

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