І саn оbvіоuѕlу fіх thіѕ bу еnhаnсіng іt bу аrоund 10 dВ but І fіnd іt wеіrd, еѕресіаllу thаt іt dоеѕn't оссur іn аll rесоrdіngѕ.

Whу іѕ thіѕ рrеѕеnt? Іѕ mу mіс mаlfunсtіоnіng?

Місrорhоnе: ѕЕ Еlесtrоnісѕ Dуnасаѕtеr DСМ8
Аudіо іntеrfасе: ІD4 МK2

 

The dead giveaway is that it "doesn't occur in all recordings." If it were a hardware defect, like a damaged capsule or a circuit issue, that dip would be there 100% of the time, no matter what. What you're seeing looks like comb filtering caused by acoustic reflections. At exactly 12 kHz, that reflected wave is "out of phase" with the direct sound, so they cancel each other out, creating that black hole in your spectrum.
That’s why it’s intermittent; just moving the mic a couple of inches or changing the tilt is enough to shift the physics and make the dip vanish, at least that's my best guess

 

I would call this a feature, that's the place I pull TDR Arbiter the most when mixing vocals. Something amazing about condensers these days.

 

When you say "pull TDR Arbiter the most", what do you mean?
I am not sure if you mean pull frequencies down, pull them up, pull out Arbiter to use in that place (frequency range?), or what you mean...

And for @canbi : This happens when all the switches are in the same position?
(Thinking that it might be more sensitive to wave cancellation with certain settings)

 

Those an aweful tidy deficits in the frequecies as shown and kinda weird to me.

 

can be some diagraphm hole(s) caused by drugs, humidity or so