Sound interference with MacMini advice sought!

[kdum8]

Hi everyone,

Since the lockdown I have been working from home like many people. I'm using various video conferencing services for work to talk to colleagues and clients. Many of them reported that they can hear interference or some kind of static noise when I am on a call with them. Muting the microphone stops this.

At first I thought it could be my headphones, or the software I was using. So I first tried multiple software (Zoom, Skype, MS Teams) to no avail. The feedback static was present with all of them, so it can't be the software.

Then I tried various input/output hardware changes to eliminate those possibilities too. I was first using a USB connected webcam with built in mike, so changed this to wireless bluetooth IEMs with a mike of their own, and then a dedicated expensive Jabra headset. It doesn't make any difference at all, my counterparts still report this irritating static noise on their end (the room is quiet). I'm at a loss as what to try next?! I wondered if it could be that somehow I'm picking up some electronic circuitry noise, the computer fan or something similar.

Does anyone have any suggestions? I'm spending hours a day on VC using this MacMini 2018 and for some reason it is giving me all this interference...

 

[Boyd01]

When my iPhone connects to the internet and transfers some data (like an incoming e-mail, etc), I sometimes get interference on other devices. Have noticed this while recording audio in Logic with a USB interface on my Mini for example. Also notice it sometimes when recording directly to my 8-track field recorder at home too. The phone appears to be using wifi when this happens.

So you might try turning off your phone (or anyone else's in the home) and see if that makes a difference. For me, this is something that only happens every now and then however, it's not a constant problem. But I live alone in a rural location with no close neighbors. In an apartment building, this might be much worse with neighbors on the other side of a wall.

 

[mmomega]

Just throwing thoughts around so none may stick. But, there isn’t an air conditioning vent that blows air anywhere near the microphone is there.
‘this was an issue I had once, I couldn’t hear it but the air going over the mic was loud to people on the the receiving side.
Worst case, even a little silly, but you can place a towel or piece of fabric over the microphone and making a test call. It may sound muffled for sure now, but you are checking to see if the previous noice is gone. If so while still on that call, remove the fabric and see if the other noise comes back. If so, it gives a better idea that you may need a ‘dead cat’ to reduce air noise around the mic but it won’t reduce your voice quality as much as a towel or heavier piece of fabric. Still can give a similar result while troubleshooting the issue.

and like Boyd mentioned, a nearby cellphone can make all kinds of strange noises to a microphone.

one other, is to try to never have two microphones or two speakers on the same call in the same room if that makes sense. Like, me and my nephew group FaceTiming my sister From the same room on deprecate devices, the two being near each other can cause massive amounts of noise feedback.

 

[ctrlzone]

it could be a fan/air cond. but from your report it's sounds like a power issue to me.
do you use a power strip? what else is connected there, older/cheap charging bricks or a Monitor in there could cause this for example, it could be the power strip too, or any of the cables.
try to connect the mac alone and the rest on another circuit.
try different outlets across the house with an extension, always connecting the mac alone.
try to use as few devices as possible, disconnect everything you don't need to test this (external HD, etc)
till you find the culprit.

 

[MevetS]

The iPhone issue Boyd01 is referencing sounds like there is something unshielded. I have an old powered speaker set that I tried to use a bluetooth receiver/transmitter with and when I connected the bluetooth device to power, there was a hum in the connected speaker. (Bringing my iPhone close to the speakers also resulted in occasional static.) So much for repurposing those speakers ...

ctrizone is also discussing this type of issue. And notes that it could be anything in the same area. It may even be something not connected to the Mac. Any electronic device could be emitting RF interference. So as ctrizone suggests, start unplugging things and hopefully one will result in the interference will disappear.

The good news is that it could be as simple as moving the offending device farther away or using a shielded cable.

Good luck tracking it down.