A few months ago, I decided to get more serious about my recording setup in my home office. I do a lot more screencasts both for my YouTube channel and for other purposes than I used to, and I can't stand poor audio quality. Therefore I finally decided to get some sound absorption panels for my office, rearrange furniture a little for better isolation, and—most importantly—buy a proper USB audio interface and microphone.
I could tweak the levels so I could get a solid signal, 10-15 bars according to the macOS System Preferences' Sound input settings:
Life was good.
But suddenly, one morning during a video chat through Zoom, others in the chat noticed that they could barely hear me! I checked the input levels and, sure enough, System Preferences said I was barely getting 1/4 of the normal levels!
Putting on my debugger hat, I first checked all the physical connections:
- I switched microphones—no difference.
- I switched inputs on the Behringer—no difference.
- I adjusted all the levels and tried to pad/not pad the inputs on the Behringer—no difference.
- I switched XLR cables—no difference.
- I tried different audio apps to see if I got any level differences—no difference.
- I plugged and unplugged the USB cable on the back of the Behringer—no difference.
Something was seriously haywire! I finally thought about the full signal path going into my Mac, and how I've had issues with my Gigabit Ethernet adapter (USB 3.0) not getting the full GigE speeds when there was a loose USB connection, or a flaky/cheap hub in the route from Ethernet to Mac... and so the next thing I tried immediately resolved the issue:
I unplugged the Behringer USB audio device from my TP-LINK 7-port USB 3 hub, and plugged it straight into my Mac.
Problem solved, full input levels again!
So, if you ever run into strange issues with your USB audio device, and it's plugged into a USB hub, check first whether it could just be a flaky USB port or a problem with the hub itself by directly plugging the device into your computer!