Mic picking up EMI noise
TLDR, Micās coil is picking up EMI from GPU. What should I do to eliminate it?
Hi, I'm new to this server.
I bought a RODE Podmic, a dynamic mic, to replace AT2020, hoping to reduce the audio leak from my K702 open back headphones entering the mic that cause an echo problem to my friends over Voip.
It did work, but introduced a new problem. I think the coil in the mic is picking up EMI from my PC.
The following are two examples.
https://youtu.be/HFmZ1S7aZMw
This video is when the system is idle. Normally I couldnāt hear the noise, but once I move the mic closer to the PC case, or point the mic towards the case, the noise became audible.
https://youtu.be/ZK_oFd3q_eM
The second one is when GPU is on load, in this case a game. The noise is audible when the mic is away from the case, and gets even worse when being close to it. You can hear the pitch shift with the gameās framerate (though I didnāt show it cuz bf2042 no longer allows RTSS overlay after changing its anticheat engine), and when ever I switch the scene, the pitch shift as well.
Iām surprised nobody seems to encounter this issue since all the info I can find that related to this topic are four post from different forum and only one of them seems to have the same cause as mine which is this one:
linustechtips.com/topic/1511291-trying-to-deal-with-gpu-coil-whine-in-microphone-audio/
Spec list if that helps:
CPU: 5950x
MOBO: ROG Strix B550-E
GPU: Inno3D iCHILL X4 3080Ti
PSU: Cooler Master V1200 Platinum 1200W (Grounded)
Case: Fractal Design Define 7 XL Black TG
Audio Interface: MOTU M4 (Podmic connected to mic in 1)
I tried using an in line mic preamp, and switching XLR cables, didnāt affect the noise at all. So the noise must be introduced on the mic, not the cable or the audio interface.
Itās not audible to human ears (except GPUās physical coil whine), so it must be EMI.
Itās not affecting my AT2020 which is a condenser mic, so it must have something to do with how dynamic mics work.
25 Replies
Have you tried moving the PC farther away
Or like
Under your desk?
You could also try a USB noise isolator
Topping HS02 USB 2.0 High Performance Audio Isolator with USB-B and...
HS02 USB2.0 High Performance AUDIO Isolator Fully lsolated Design: The HS02 has a fully isolated design, which does not introduce new interference when the auxiliary power supply is used while the audio signal is isolated from ground loop interference. Say goodbye to ground loop and hum. Switchin...
Thatās an expensive one but thereās loads of cheaper options
Yes I've tried but my room is small and the noise in the video is already the lowest I can get. Under desk won't help since my desk is wood and not grounded thus make no use for isolating EMI.
I checked the noise isolator you mentioned and it seems its for ground loop noise? Mine isn't caused by a ground loop.
are your xlr cables isolated from any power/data cables?
I don't know what qualifies 'isolated' but they are mogami 2534 and are at least 30cm away from the nearest USB cable and even more from AC power cables.
I just find two possible solutions to this
David āDEVOā Harry
YouTube
How To Fix RFI Radio Frequency Interference Neumann Microtech Gefel...
SmartRig Amazon USA: http://amzn.to/2tGzseL UK: http://amzn.to/2uWpHcM In this video I explain a simple cable modification that may help people with RFI Radio Frequency Interference or EMI Electromagnetic Interference on Microtech Gefell and Neumann microphones.
I can say that this is a fix for everyone but it's worked for me on a number of...
Sound Speeds
YouTube
Neutrik EMC XLR Connectors - Sound Speeds Review
In this review I go over the features of Neutrik EMC XLR Connectors. They claim to eliminate ground loops and help with RF rejection but how is this possible with just an XLR connector? Let's dive in and see!
To purchase Neutrik EMC female connectors:
http://geni.us/EMCF
To purchase Neutrik EMC male connectors:
http://geni.us/EMCM
For info abo...
I'm not sure if this is the same case but I hope it is.
I never picked up any RFI, or at least I think I didn't. Only EMI.
I tried to move the cable around and it didn't change the noise signature. The noise only get louder if the mic itself gets closer to the EMI source. I don't think it's the cable that's the problem here.
GG @Soracyti, you just advanced to level 1 !
Built a XLR cable with mogami 2534 and 2 neutrik EMC connectors, no improvement.
Do you know what is the source of EMI?
Yeah like crank up your gain or monitor mix and move the mic around stuff on your desk/your PC
It's the GPU since the noise signature shifts with framerate changes (see the second video)
Oh and the noise is loudest when I stick the mic to GPU
Forgot to mention that in the post
It sounds like youāre getting EMI from the power draw of your GPU bleeding into your motherboardās power distribution
I would buy whatever cheap USB ground loop isolation dongle you can get that seems decently review and see if that changes anything
If not I would look into getting a dedicated power supply for your interface
Youād probably need some sort of usb splitter that divides the data and power to separate ports though and I donāt even know where to start with that
B series motherboards arenāt exactly high end when it comes to power distribution
It's the coil that's picking up the emi
I tried connect my interface to a laptop and monitor the EMI from other PCs and the mic is still picking up different EMI from different PC
I'm trying to find a way to easily shield the mic like a faraday cage or smth
At first I thought it's because the mic's housing wasn't properly grounded so the housing wasn't forming a faraday cage
How will a USB ground loop isolator help in this case I'm a little confused
GG @Soracyti, you just advanced to level 2 !
Iām not sure if it will help Iām saying try it to see if it does
If it doesnāt you can just return it
If it does congratulations problem solved
The EMI sound could still be a feedback loop
Could get shielding tape for inside your case around where the GPU is
I tried to disconnect the ground wire of my PSU first, will this do the same trick? It didn't work though.
Uh what no donāt do that what
I'm in japan and the plug looks like this so
the ground wire is seperate
RODE's CS just get back to me and said it's a defect though I doubt it. I think im done troubleshooting this. Thank you for all your valuable suggestions.
Let us know if the new one fixes it!
UPDATE: After sending the mic to local CS for inspection they came back with this one line of diagnosis: "Not like EMI noise but it seems like mechanical noise shows in our facility as well. "
I don't know what that means but they arranged a replacement for me and the new one so far appears to be more resistant to EMI than the old one, inaudible during normal usage but will still pickup EMI if get too close to the PC.