Hi,
Lets put it this way, if you have all the same value caps and the 0db point
occurs at 2kHz with three caps, when you short out the left side of
the caps to each other you dont change the frequency response at all,
so the 0db point still occurs at 2kHz. This happens because once the
three caps are shorted they equal three times the original value of one
cap.
If you then decrease the value of that cap (three times higher than one)
to one third of its value you of course raise the 0db point by 3 times its
original frequency, in this case it would be 6kHz.
But you had said that the cap value wont affect the frequency of operation,
so that voids the above argument so you wont see any difference as long
as the caps lowered to 1/3 of their original value dont affect operation
either.
In other words, if you operate at 300Hz and you use 10uf caps i doubt you
will ever see a difference. If you change to 100pf caps you will.