C13 8-string bass chord

How to play C13 on 8-string bass

The most common way, the first shape above: your index finger on the B string at the 1st fret, your middle finger on the A string at the 1st fret, your ring finger on the D string at the 2nd fret, your ring finger on the G string at the 2nd fret, your ring finger on the C string at the 2nd fret and your ring finger on the F string at the 2nd fret. Don’t play the F♯ and E strings.

From the F♯ string x 1 x 1 2 2 2 2 (x: not played, 0: open)

What notes are in C13?

C13, C dominant thirteenth, is C, E, G, B♭, D and A: the root (C), the major third (E), the perfect fifth (G), the minor seventh (B♭), the ninth (D) and the thirteenth (A). Its formula is 1 3 5 ♭7 9 13.