Tuning a low B string
The low B on a 5-string bass sits at about 31 Hz, below what a phone microphone really hears. That is where most tuner apps struggle. Here are the notes, a way to check by ear, and what we measured.
5-string bass (B E A D G)
The low B on a 5-string bass is B0, 30.87 Hz: the lowest note most players ever tune.
| String | Note | Frequency |
|---|---|---|
| String 5 | B0 | 30.87 Hz |
| String 4 | E1 | 41.20 Hz |
| String 3 | A1 | 55.00 Hz |
| String 2 | D2 | 73.42 Hz |
| String 1 | G2 | 98.00 Hz |
7-string guitar (B E A D G B E)
A 7-string guitar adds B1 below standard tuning, one octave above a bass’s low B.
| String | Note | Frequency |
|---|---|---|
| String 7 | B1 | 61.74 Hz |
| String 6 | E2 | 82.41 Hz |
| String 5 | A2 | 110.00 Hz |
| String 4 | D3 | 146.83 Hz |
| String 3 | G3 | 196.00 Hz |
| String 2 | B3 | 246.94 Hz |
| String 1 | E4 | 329.63 Hz |
Baritone guitar, B standard (B E A D F♯ B)
B standard tunes a 6-string baritone guitar a fourth below standard tuning.
| String | Note | Frequency |
|---|---|---|
| String 6 | B1 | 61.74 Hz |
| String 5 | E2 | 82.41 Hz |
| String 4 | A2 | 110.00 Hz |
| String 3 | D3 | 146.83 Hz |
| String 2 | F♯3 | 185.00 Hz |
| String 1 | B3 | 246.94 Hz |
1. Tune the E string first
Get the E string right, then use it as your reference for the B.
2. Pluck the B with your finger
A firm pluck over the neck pickup gives the microphone the most to work with.
3. Check at the 5th fret
Fret the B string at the 5th fret. It should match your open E.
Measured, not claimed
On 25 low B clips, the median error of Tune Right’s pitch detector fell from 10.49 cents in version 2.12 to 1.84 cents in 2.13, and 92% of them settled within 5 cents. The full results and method are on the accuracy page.
What note is the low B string?
On a 5-string bass it is B0, at 30.87 Hz. On a 7-string or baritone guitar it is B1, at 61.74 Hz, one octave higher.
Why is low B so hard to tune with a phone?
A phone microphone barely picks up anything at 31 Hz, so the tuner has to work out the note from its overtones. Many tuners wander or show the note an octave too high.
How do I check my low B without a tuner?
On a 5-string bass, fret the B string at the 5th fret. That note is E1 and should match your open E string.
Does Tune Right have a 7-string guitar preset?
Not yet. It has a 5-string bass preset with the low B. For a 7-string or baritone guitar, use chromatic mode with the notes on this page.