Macroscopic (APSD and CPSD) and microscopic (Rossi-??) neutron noise experiments were performed in the IPEN/MB-01 reactor in order to measure subcritical reactivities. Subcritical states of up to around -6600 pcm were reached with insertion of boric acid (H3BO3) into the moderator tank. The subcritical kinetic model of Gandini and Salvatores was employed to infer the relative power between two consecutive subcritical cases, the subcritical reactivity (????gen), and the subcriticality index (????). This experimental methodology to measure these parameters was successfully employed in a previous experiment performed in the IPEN/MB-01 reactor. The measured subcritical reactivities are in good agreement for the APSD and Rossi-?? cases. However, some drawbacks were found for the CPSD cases due to difficulties in the establishment of the cutoff frequency. The MCNP6.1 calculated subcritical reactivities were in a good agreement to APSD??s and Rossi-?? measurement values. The ENDF/B-VII.0 nuclear data library was employed in all cases.