Question Why does my microphone produce white noise, even when it's unplugged?

[ShawnSMB]

I have a condenser microphone ( the Audio Technica 2020), and I have it connected to a phantom power supply. When I listen or record the microphone audio, I hear a constant loud hissing sound, there is no sound in my room that should be producing that loud of a sound. I thought it was my microphone so I got a new one, but the issue remained. I've tried both an XLR to 3.5mm and an XLR to usb cable, but they both produced the noise. I unplugged the phantom power supply, so only the 3.5mm jack was plugged into the computer with no microphone connected and it still produced the noise! That leads me to believe that the issue has to do with my computer, not the peripherals. I've tried using a sound card, but it seems to have only made the issue worse.

I was thinking about getting an audio interface/mixer, but I'm not certain if that would fix it either.

You can see an example of the noise here:

View: https://youtu.be/g90WDCiGjFE

*Note, the audio recorded is with the microphone unplugged

 

[rounakr94]

It's interference from other components in the pc which are not shielded.

 

[ShawnSMB]

It's interference from other components in the pc which are not shielded.

How do I fix this issue and could an audio interface bypass this issue?

 

[digitalgriffin]

Sounds like a floating ground issue, or EMF interference.

First, lets determine it's not your DAC or speakers/headphones:

If you take a recording from the net, do you hear any background noise?

If playing nothing, and you turn up the speakers (computer output on mute) do you hear noise?

If headphones, have you plugged them into something other than a computer like a home receiver?

Plug in the computer speakers, turn them up to near full. Slowly turn up the computer volume from zero. How far up the 100 scale can you get before you hear noise?

 

[ShawnSMB]

Sounds like a floating ground issue, or EMF interference.

First, lets determine it's not your DAC or speakers/headphones:

If you take a recording from the net, do you hear any background noise?

If playing nothing, and you turn up the speakers (computer output on mute) do you hear noise?

If headphones, have you plugged them into something other than a computer like a home receiver?

Plug in the computer speakers, turn them up to near full. Slowly turn up the computer volume from zero. How far up the 100 scale can you get before you hear noise?

I only hear the noise while listening to my microphone, whether it be by hitting listen in microphone settings or recording in audacity.

 

[digitalgriffin]

I only hear the noise while listening to my microphone, whether it be by hitting listen in microphone settings or recording in audacity.

I'm trying to rule out the microphone & ADC from the equation as the source of the noise. The noise might be coming from other sources. Hence my test. That's why my instructions did not have you do anything with the mic. (Which should be disconnected)

 

[ShawnSMB]

Sounds like a floating ground issue, or EMF interference.

First, lets determine it's not your DAC or speakers/headphones:

If you take a recording from the net, do you hear any background noise?

If playing nothing, and you turn up the speakers (computer output on mute) do you hear noise?

If headphones, have you plugged them into something other than a computer like a home receiver?

Plug in the computer speakers, turn them up to near full. Slowly turn up the computer volume from zero. How far up the 100 scale can you get before you hear noise?

Not sure what you mean by "take a recording from the net", If playing nothing, I do not hear any white noise, and I never plugged my headphones into something other than a computer. Also, I have heard this white noise with multiple headsets, when listening to microphone.