Bass Guitar Tuner — 4-String EADG and 5-String BEADG

A four-string bass guitar is tuned EADG, an octave below the bottom four strings of a guitar: E1, A1, D2 and G2 with A4 = 440 Hz. A five-string adds a low B0 below the E. The lowest strings are the hardest notes for a microphone tuner to read accurately. If you searched for bass guitar online or how to play bass, start here and get in tune first.

How to use it

1. Start the tuner. Press Start Tuner (Microphone) and allow microphone access. The audio is analysed in your browser; nothing is uploaded.
2. Choose the right preset. The selector above carries the 4-string (EADG) and 5-string (BEADG) tunings. Pick the one that matches your instrument before you play a note.
3. Mute the other strings. Rest the side of your plucking hand across them. A bass has a lot of low energy and its strings ring for a long time, so a neighbour ringing under the note is a common cause of a reading that will not settle.
4. Play close to the microphone. Hold the device a hand’s width from the instrument, near the strings between the bridge and the neck. Distance costs more on a bass than on any other instrument on this site.
5. Use the neck pickup on an electric bass. It hears more of the fundamental and less of the bright harmonics, which is exactly what the low strings need.
6. Pluck with the thumb or the flesh of a finger, near the neck. A pick near the bridge adds attack and harmonics; a rounder note gives the detector a cleaner fundamental to work with.
7. Let the note ring, then re-pluck if the reading drifts. A bass note decays slowly, so the display usually has time to settle — but if it moves, play the string again rather than waiting.
8. Tune up to pitch. If a string is sharp, lower it below the target and bring it back up. Finish with the low strings last, because they move the most as the neck settles.

Bass string frequencies

4-string (EADG)

String	Note	Frequency (A4 = 440 Hz)
4th (lowest)	E1	41.20 Hz
3rd	A1	55.00 Hz
2nd	D2	73.42 Hz
1st (highest)	G2	98.00 Hz

5-string (BEADG)

String	Note	Frequency (A4 = 440 Hz)
5th (lowest)	B0	30.87 Hz
4th	E1	41.20 Hz
3rd	A1	55.00 Hz
2nd	D2	73.42 Hz
1st (highest)	G2	98.00 Hz

To find and memorise every note along the neck for both setups, see our complete bass fretboard notes guide, or practise fingerings and plucks directly on our interactive Virtual Bass Guitar.

The low E and the low B

The low strings are the reason this page needs a section of its own. For notes below 70 Hz — on this page the low E and the low B — the tuner switches to its decimated low-frequency detector: a 33-tap Blackman-windowed sinc anti-aliasing filter, then 4x decimation of the 4096-sample buffer to 11.025 kHz, and the full 1024-sample decimated window (~92.9 ms) is what gets correlated. That window holds roughly 1.7 periods of B0 and over 2.3 of E1, so the detector has the periods it needs. What is left is the microphone: small capsules roll off below roughly 100 Hz, so confirm the lowest strings by ear or against a harmonic instead of trusting a single frame.

• The low B is the hardest note on the page. At 30.87 Hz its fundamental is barely reproduced by a phone or laptop microphone, and what the microphone hears most strongly may be the string’s harmonics rather than its fundamental.
• An octave jump is the weak-fundamental symptom. When the display leaps to B1 or E2, the detector has locked onto a harmonic. That is a real note, but it is not the open string’s pitch.
• The low strings still sound enormous in the room. The energy is there; a small microphone capsule simply does not capture the bottom of it. Do not conclude that the string is quiet because the display is unsure.
• A five-string’s low B rewards patience. Give the string a full second to ring, keep everything else muted, and expect to re-pluck once or twice before the reading settles.
• The 5th-fret check is the reliable cross-check. The low B played at the 5th fret sounds E1, the same pitch as the open 4th string, so a steady E reading confirms the B string’s pitch even when its own fundamental will not read.
• The 12th-fret harmonic is one octave up and easier to read. For the low E that is E2 = 82.41 Hz; for the low B it is B1 = 61.74 Hz. If the open string will not settle, compare the harmonic with the string card instead.

Getting a clean reading

The physical setup around the instrument matters as much as the string itself:

• Close beats far. A hand’s width from the strings is a good starting distance. Across the room, the low strings arrive too weak to hold a reading.
• One string at a time. Mute the others with the side of your hand; a bass’s open strings sustain for seconds and will ring through your tuning.
• The neck pickup and a rounder pluck. Both shift energy into the fundamental, which is the part of the note the tuner needs.
• An amp can help or hurt. If you are plugged in, the microphone hears the amp instead of the instrument. A cabinet with a larger speaker reproduces the low strings better than the phone’s own microphone, but the room and the amp’s tone colour the note — keep the amp at a modest volume and stay close to it.
• Watch the tone control. Rolling the treble back emphasises the fundamental; a bright, scooped tone pushes energy into the harmonics and makes the low strings harder to read.
• Re-pluck rather than waiting. A bass note’s fundamental is strongest right after the pluck and decays from there. If the display drifts, play the string again.

Intonation and the harmonic check

Tuning the open strings is only half of a bass being in tune. If the open string is right but the instrument sounds wrong further up the neck, the problem is intonation, not tuning.

• Compare the 12th-fret harmonic with the fretted 12th fret. The harmonic sounds an octave above the open string; the note fretted at the 12th fret should be the same pitch. If the fretted note is sharp of the harmonic, the string’s speaking length is too short; if it is flat, it is too long.
• Intonation is a saddle adjustment. The bridge saddles set each string’s speaking length. A bass set up for one gauge and tuning will not be perfectly intonated at another, which is why a gauge change is worth a setup.
• Check the fourths across the neck. The 5th fret of each string sounds the next open string: the E string’s 5th fret is A1, the A string’s 5th fret is D2, the D string’s 5th fret is G2. On a five-string, the B string’s 5th fret is E1, the open 4th string.
• Check intonation after any setup change. Action, relief and saddle height all affect how far a string is stretched when fretted, so a change to one can move the others.
• Check the octave harmonic by ear if the display is unsure. Comparing the harmonic with the fretted note is a pitch comparison, so it works even when the microphone is struggling with the fundamental.

Accuracy and limits

• Below roughly 50 Hz the reading is approximate. The low E (41.20 Hz) and the low B (30.87 Hz) are the two notes this applies to. The detector reads them on the decimated low-frequency path — 4x decimation of the 4096-sample buffer to 11.025 kHz and a 1024-sample window of about 92.9 ms, roughly 1.7 periods of B0 — so the remaining margin is the microphone’s, and no adjustment to the room or the playing changes that.
• Small microphones lose sensitivity at the bottom of their range. Laptop and phone microphones typically roll off below roughly 100 Hz, so the low strings arrive quieter than they sound in the room. Play close and keep the note ringing.
• A weak fundamental can produce an octave error. If the display reads B1, E2 or G3 while you play the string below it, the fundamental has lost the fight with its harmonics. Mute everything else, pluck again, and check the octave against the card.
• Very low rumble is rejected rather than shown. Pitches below the bass’s range do not produce a reading, so a passing lorry or a ventilation system will not be reported as a note — but it can still mask the string you are trying to hear.
• The low strings settle slowly after a restring. A new bass string stretches for hours of playing, and the low B for longer. Expect to retune several times after a change.
• A string that is in tune open but sharp at the 12th fret has an intonation problem. More tension on the fretted note means the speaking length is wrong; a saddle adjustment fixes it.
• A dead or worn string reads poorly and sounds dull. If one string reads unsteadily while its neighbours are fine, the string may simply be old.

Safety

• Bass strings are under high tension. Tune up in small increments and stop at the target. The low strings carry the most tension on the instrument.
• Do not force a stiff tuning machine. A machine head that will not turn is usually binding; forcing it can strip the gears or twist the string.
• Change strings one at a time. Keeping the rest of the set at pitch holds the neck’s tension steady and keeps the bridge and saddles in place. If you change gauges, the truss rod and intonation will need a setup.
• A slackened thick string can whip. When you release the tension on a low string, control the loose end rather than letting it spring free.
• Never adjust the truss rod or saddles by force. These are setup adjustments; a quarter turn that will not move means the job belongs with a technician.
• Mind your hearing and your back. A bass in a small room produces a lot of low-frequency energy, and the instrument is heavy. Keep amp levels sensible and use a strap and good posture.