Bass Tuner

How to Use This Bass Tuner

1. Press Start Recording on the tuner above and allow microphone access.
2. The Bass Guitar instrument is already selected.
3. Start with the E string (string 4, 41.20 Hz). Pluck firmly over the neck pickup and let it ring.
4. Mute the strings you are not tuning with your palm. Sympathetic vibration from open strings is the most common cause of an unstable reading on bass.
5. Work up through A, D, and G, centring the needle at 0 cents on each.

Standard Bass Tuning Explained

A 4-string bass in standard tuning is E A D G, tuned in perfect fourths. The pitches are E1, A1, D2, and G2 — exactly one octave below the equivalent strings on a guitar.

Tuning entirely in fourths, with no major-third break between the G and B strings that guitars have, is what makes bass fingering so consistent: a scale or arpeggio shape works identically anywhere on the neck, with no adjustment when crossing strings.

Why Low Notes Are Hard to Detect

Bass presents a genuine technical problem for any microphone-based tuner, and it is worth understanding so you can work around it.

The open E string vibrates at 41.20 Hz. Most built-in microphones in phones and laptops are optimised for the human voice, which sits between roughly 85 Hz and 255 Hz, and they attenuate heavily below that. The fundamental of your low E may barely register.

What saves the situation is that a plucked string produces a whole harmonic series, not just the fundamental. The second harmonic of the low E is at 82.40 Hz and the third at 123.60 Hz, both well within microphone range. Our pitch detection uses autocorrelation, which recognises the repeating period of the whole waveform, so it can resolve the correct fundamental even when the microphone barely captures it.

Practical consequences:

• Pluck over the neck pickup, not the bridge. This emphasises the fundamental and lower harmonics.
• Use a firm, consistent pluck. Too soft and there is not enough signal; too hard and the initial attack sharpens the pitch briefly.
• Wait about half a second before reading. Let the attack transient pass and the note settle.
• Mute the other three strings. They will ring sympathetically and confuse the reading.

Common Bass Tunings

• Standard (E A D G): The default for virtually all genres.
• Drop D (D A D G): The E string lowered a whole step, matching guitarists playing Drop D.
• Half step down (E♭ A♭ D♭ G♭): Everything down a semitone to match a guitarist in E♭.
• 5-string (B E A D G): Adds a low B below standard. See our 5-string bass tuner.

The rule when playing with a band is simple: whatever the guitars are tuned to, the bass matches. A bassist in standard against guitars in Drop C will clash on every open string.

Troubleshooting

The needle jumps between two notes. Almost always sympathetic ringing from an open string you are not playing. Mute everything except the string being tuned.

It reads an octave too high. The tuner has locked onto the second harmonic instead of the fundamental — common when plucking hard near the bridge. Pluck more gently over the neck pickup.

It reads sharp immediately after plucking, then settles. That is real, not an error. A hard pluck stretches the string slightly and raises its pitch for a moment. Read the needle after the note settles.

Nothing registers at all. Check that your browser has microphone permission, and that no other application is holding the microphone open.

Also available: our 5-string bass tuner, ukulele tuner, and the standard chromatic guitar tuner.