Yes, I had a chance got Behringer C-2/B-5/C-4/C-1/C-3 and took apart them, checked the circuit and mic capsule , compared with Samson C01 , At2020 and
At2020USB.
Behringer C-4 is completely copied from Behringer C-2 (C-2 seems made by 797 audio in Beijing), but the mic capsule in C-4 is bad, and found a strange thing, seems the designer of
behringer C-4 did not know microphone, there is a hard foam at the rear side of the C-4 mic capsule (in C-2, it is a soft foam as damp for high frequency ), the hard foam completely stopped the rear side sound, so most C-4 is omni directional, but C-4 should be a cardioid mic. I am wondering how Behringer controll the quality of C-4, maybe they never done QC for the mics which are made in House.
behringer C-1/C-3 are with same bad capsule as C-4.
the B-5 capsule seems similar as PMI audio C-4/Rode NT4 capsules, should be made by 797 Audio?
Samson C01 is with a similar low quality 16 mm capsule as the C-4.
At2020/At2020USB is with the best 16mm mic capsule, the diaphragm of the mic capsule is with wave, seldom mic is with waved diaphragm, I only sawed waved diaphragm in some much small mic capsule such as shure/EV/At 10mm mic capsules.