the world > relative properties > order > agreement, harmony, or congruity > adaptation or adjustment > [noun] > in due proportion > one who or that which (3)
modulator1654
A person who or thing which modulates something; (later chiefly) a regulator, a controlling mechanism.
modulant1869
A thing which effects modulation; a modulating agent.
proportioner1901
A person who or thing which proportions something. Now rare in general sense.