How to Tune a Bass Guitar Online
Standard 4-string bass tuning is E1, A1, D2, G2: the same pitches as a guitar's bottom 4 strings, one octave lower. The lowest E string vibrates at just 41.2 Hz; many laptop microphones struggle below 100 Hz, so plugging the bass into an audio interface is ideal. If using a mic, place it close to your speaker cab if amped. Pluck firmly with your fingertip for a clean fundamental.