Getting low input level with a USB mic or audio interface? Check your hub

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.

So, after purchasing and connecting a U-Phoria UMC202HD and an Electro-Voice RE320 microphone, I was quite pleased with the sound quality!

I could tweak the levels so I could get a solid signal, 10-15 bars according to the macOS System Preferences' Sound input settings:

Input bars at 15 - good sound in System Preferences Sound Input panel

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!

Input bars at 6 max - not good sound in System Preferences Sound Input panel

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!

Comments

Hey, Nice advice, but I'm using the U-Phoria UMC22 and using a laptop running windows 10 OS and connecting the audio interface directly to the USB ports on the laptop and it is still having a low input level and barely audible, if I wish to make the mic louder I had to increase the gain which in turn gives out loud and noticeable static noise. Have any other ideas? Thanks in advance.