Per google: C Note Frequencies by Octave
C0: 16.35 Hz
C1: 32.70 Hz
C2: 65.41 Hz
C3: 130.81 Hz
C4 (Middle C): 261.63 Hz
C5: 523.25 Hz
C6: 1046.50 Hz
C7: 2093.00 Hz
C8: 4186.01 Hz
I suppose it's as fine a way as any to choose frequency centers, but I don't see how it could possibly ensure...