I've been trying to diagnose why my condenser mic keeps buzzing for ages.

I'm running it through an audio interface, but it still had a noisey 'buzz' that sounds like a very common electric hum (near large electric transformers). This also occurred when run through a laptop running on batteries (with the AC input / charger disconnected).

Strangely the buzz would get stronger if I got near to the mic with my face / body.

If I touched the mic or the audio interface the sound would dampen significantly (but return to the normal behavior once I removed contact).

I was trying random things today and then by accident I touched the mic grill with a screwdriver, and the buzz immediately went away and now it's crystal clear (even without keeping contact with the screw driver).

What on earth is the cause of this? Is it some static build up? Incorrectly grounded?

It previously worked crystal clear the other day. The buzz / interference is either significant in effect, or completely unnoticeable, with nothing in between.

I'm just so glad I found a solution to this.

  • Is this a 'simple' buzz, like a mains hum, or more 'complex', changing in pitch & sounding more like a motorboat?
    – Tetsujin
    Jul 5, 2018 at 17:08
  • Here is a previous recording (with the buzz present): youtube.com/watch?v=o8VZ-OL1mgM&feature=youtu.be Jul 5, 2018 at 17:15
  • broken link - empty page.
    – Tetsujin
    Jul 5, 2018 at 17:28
  • Sorry, fixed it now. Jul 5, 2018 at 18:28
  • 1
    You can test the loose ground theory by attaching a wire from the casing to the grill. If that fixes it, you've found the cause of the problem and now you can find what the best way of fixing it is. Maybe shove some thin wire threads where the grill attaches to the casing as long as they don't rattle/resonate.. Jul 7, 2018 at 17:06

2 Answers 2


Sounds like loose grounding connection to the grill. See whether you can take the mic apart and give the grill a tiny bit of deformation in a manner where it touches the (hopefully grounded) casing of your mic with a bit more tension and/or give it a slight brush with a file where it is supposed to have contact.

Of course, if there is an actually more dedicated way of grounding the grill, make sure that it works.


4 years later... I was getting similar buzzing again (this time with a different audio interface), strangely doing the usual trick with the screwdriver / grounding the grill did not have any effect.

I opened this mic up with just 4 screws, and just blew a bit of air on the mic input, and also found two stray hairs inside the mic compartment (behind the grill) and that solved the issue once again.

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