Originally Posted by Reddog01
This chart is incorrect -- it's showing the tuning notes one octave too low. The highest string, G, is the first G below middle C. This chart show it one octave too low.
No, the chart is correct. Bass music is notated one octave higher than it sounds for ease of reading (as is guitar music). So, the open G string as is written on the staff as being in the top space of the bass clef, a fourth below middle C, but the actual note sounds one octave below that, as shown in the chart.
To answer the OP's question, the low E on a standard bass is E1, 41.2 Hz and this is the same pitch as the lowest E on the piano (despite being written for bass as if it was one octave above that). The lowest piano keys on a conventional instrument are A0, A#, B0 (lowest note on a 5 string bass), C1 et cetera. Note that octave numbers change when you get up to C. So, the lowest E on the piano is E1, same as the open E on your bass. E0 is 20.6 Hz and a perfect fourth below the bottom A on the piano.