The search for empirical schemes to evidence the quantumness of large masses is a central quest of current research. However, practical schemes to witness the irreducible quantumness of an arbitrarily large mass are still lacking. To this end, we have proposed a new scheme to demonstrate genuine quantumness of harmonic oscillator systems. Our adaptation enables probing quantumness for literally any mass, momentum, and frequency. Moreover, coarse-grained position measurements at an accuracy of the order of standard quantum limit, as well as knowing the relevant parameters only to this precision, without requiring them to be tuned, suffice for our proposal. These should drastically simplify the experimental effort in testing the quantumness of massive objects ranging from atomic ions to macroscopic mirrors in LIGO.