Tuning a bass by ear
Press E1 and pluck the thickest string. When the string and the tone are close, their combined sound wobbles in loudness, and the wobble slows as you turn the peg toward the right pitch. At the fundamental that wobble can be very slow: a string only 0.5 Hz off beats once every two seconds. Laptop and phone speakers play almost nothing at 41 Hz, though, so what you hear on them is the overtones beating, at two and three times that rate (1 to 1.5 times a second for the same string). All the beats slow down together and stop when the string is in tune, so let each note ring for a few seconds before you decide. Turn the peg in small steps and pluck again. Pressing the button that is playing stops the tone.
The open strings are easier to hear through headphones or a bass amp than through a laptop. If you tune through your amp while the tone plays from a phone, keep the phone close to you and the amp at a moderate level so that neither sound covers the other.
Open strings and their harmonics
| String | Open string | 12th-fret harmonic |
|---|---|---|
| 5th (5-string only) | B0 · 30.87 Hz | B1 · 61.74 Hz |
| 4th (thickest on a 4-string) | E1 · 41.20 Hz | E2 · 82.41 Hz |
| 3rd | A1 · 55.00 Hz | A2 · 110.00 Hz |
| 2nd | D2 · 73.42 Hz | D3 · 146.83 Hz |
| 1st (thinnest) | G2 · 98.00 Hz | G3 · 196.00 Hz |
The frequencies are equal temperament with A4 at 440 Hz, the ISO 16 standard pitch. Harmonics are twice the open-string frequency, which is why the second row of buttons is the exact octave above the first.
Why a sawtooth wave, and why harmonics help
A sawtooth contains every multiple of its frequency: at E1 that means energy at 41, 82, 124, 165 Hz and higher. Small speakers drop the lowest of these, but your ear still hears the pitch of the missing bottom note from the pattern of the ones above it. That effect is called the missing fundamental, and it is why the low E still reads as E on a laptop. If you listen on headphones that go deep, switch the waveform to Sine for a pure tone without the buzz.
The same logic makes 12th-fret harmonics a good way to tune on small speakers: they sit an octave higher, where the speaker plays the comparison tone much more strongly.
Related pages
The guitar’s four lowest strings are the same notes one octave up: see guitar tuning. To find out how low your speakers or headphones really go, run the bass test on the speaker test. Any other note or frequency is on the tone generator.