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!


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.

Same problem! It seems odd that I need to jack the input levels on my MAC and the interface, literally to the max, to get just mediocre levels. This can't be right...

Same issue here. U-Phoria UMC202HD plugged directly into 2019 Mac Pro with Catalina 10.15 via USB-C, and have to have gain ~70% and output at 100% to get mediocre input sound level on mac. Anyone have any ideas? I've tried moving to other USB slots with no luck.

Some mics don't output a very good level. I bought a Cloudlifter to boost the mic signal for my EV RE320 to get it to a level that was more usable. Previously I had the input turned up to 100% and I had to be pretty close to the mic just to get a good signal. Now with the preamp I can leave the volume nearer 50-60% and I get a much cleaner signal.

Using an old PC in Win10, with a Behringer 204HD, I had the same issue with low levels. I'd automatically plugged the Behringer into the laptop's sole USB 3.0 port, assuming that would be the best option. I found, and promptly lost again, a post from someone else suffering low levels suggesting that plugging into the USB Type 3 (blue) socket caused the volume drop, and lo and behold, I tried switching to a USB2 port and the levels came back.
I think the post said there may be a firmware fix for the Behringer, but you have to apply it via a USB2 port; once updated then you could plug into USB3.0; USB-C presumably is suffering a similar issue with updates to the USB protocols that the Behringer firmware couldn't handle. I'm not sure how you'd get around the issue if all your ports are more modern though I'm afraid.

Had an issue like that. Found it to be some software that recognized to high input om mic when I was turning on power of my preamp. The fix was, open tool for MIDI and sound setup. Go to sound in on Behringer device. Adjust volume of main channel to max again.

I’ve tried your suggest and its surprisingly worked! I didn’t thought that the USB port can make much different. Thank you

Thanks for this. I had been searching for similar issues and never considered the USB adaptor. I had added a second monitor, using same multifunction adaptor and was having all sorts of USB microphone issues...too low, way too hot. Duh, the adaptor.

Whether you're using a desktop, laptop or Mac, you should always look at specs of your device and see how much power each USB outputs. Devices like UMC202HD require quite a bit of power that not all USB sockets, and certainly not USB hubs without external power supply, are able to provide. Hubs without external power supply should be only used for things like keyboards, mices, pendrives, HDDs below 1TB. For anything more power hungry you should plug directly or use an externally powered hub.

Uphoria UMC1820. same thing happened to me. plugged USB into a usb 3 hub chained into a caldigit T3 HUB into my macbookpro 16.1
everything was fine for months til one day all 8 inputs passed uncharacteristically LOW signal. finally found this thread and replugged the USB directly into the caldigit HUB.. back to normal!! thank you it was driving me bonkers!