I'd try a pair of cheap "measurement"
mikes like the T-bone MM-1,
Behringer ECM8000 etc. They're omni and the capsule is certainly
small !
The Behringers are very noisy, and they vary wildly in characteristics
from unit to unit. They're literally made with whatever was cheapest
that day from any given supplier.
I use them as 'starting points' for building nicer calibrated mics
because I can reuse the bodies, PCB and connector. And for $39,
that's cheaper than starting from raw components. But the first thing
I do is toss the capsules and half the electronics on the board.
They're literally hilarious on the inside.
In short--- they're worth the $40 as parts, but not quite as a mic.
Monty