There is no two octaves below a regular bass guitar. On a 5 string bass, the lowest string is B0 in standard tuning, coming in at 30hz. You can get a long sca

There is no two octaves below a regular bass guitar. On a 5 string bass, the lowest string is B0 in standard tuning, coming in at 30hz. You can get a long scale length bass and put really chonky strings on it and drop that down as low as E0, which is 20hz, but past that point most people just can't hear the notes anymore.