Double Bass Tuner — EADG and BEADG for the Lowest Strings

A double bass is tuned EADG, in fourths, and sounds an octave below written pitch: E1, A1, D2 and G2 with A4 = 440 Hz. A five-string adds a low B0. These are the lowest strings on this site, and the hardest for a small microphone to hear.

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. Bow if you can. An arco note sustains, which gives the detector far more to work with than a decaying pizzicato note.
4. Play close to the device. Hold the phone or laptop a hand’s width from the bridge or the f-hole area, aimed at the body. The bass radiates from a large area, and distance loses the low end first.
5. Play one string at a time. Stop the other strings with your left hand or the side of your bowing hand; a bass rings for a long time and a neighbour can dominate the display.
6. Let the note develop, then re-pluck or re-bow if the reading drifts. The low strings take a moment to speak and their fundamental is strongest early in the note.
7. Tune up to pitch. If a string is sharp, lower it below the target and bring it back up.
8. Check the fourths. Bow or play two adjacent open strings together and listen for the beating of a fourth that is not quite pure. The pulse stops when the interval is in tune.

Double 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

The lowest strings and what a microphone can hear

Below 70 Hz the detector reads these strings on its decimated low-frequency path: the 4096-sample frame passes a 33-tap Blackman-windowed sinc anti-aliasing filter, is decimated 4x to 11.025 kHz, and the full 1024-sample decimated window (~92.9 ms) is correlated — about 1.7 periods of B0 and over 2.3 of E1. The limit is no longer the analysis window but the microphone: the fundamental of the low E and low B is below what a phone or laptop reproduces well, so treat the lowest readings as approximate and confirm them against a harmonic or by ear.

• The low B is the lowest note on this site. At 30.87 Hz its fundamental is at the very bottom of what a small microphone can register at all. The microphone may report the string’s harmonics instead, and the display can sit an octave above the open string.
• The low E is only slightly easier. At 41.20 Hz it is still below the region where small microphones are comfortable, and its fundamental can arrive weak enough for a harmonic to take over.
• The energy is real; the capture is the problem. A double bass moves a lot of air at those frequencies. The room hears it; a small microphone capsule does not reproduce it faithfully.
• An octave error is a real note at the wrong pitch. If the display reads E2 or B1 while you play the string below, it has locked onto a harmonic. Check the reading against the string card and the harmonic check before you adjust anything.
• The 5th-fret check confirms the pitch without the fundamental. On a five-string, the low B played at the 5th fret sounds E1, the same pitch as the open 4th string; on a four-string, the E at the 5th fret sounds A1, the open 3rd string. A steady reading there confirms the string’s pitch.
• The octave harmonic is easier to read than the open string. The harmonic at the midpoint of the string sounds one octave above the open note — E2 = 82.41 Hz for the low E, B1 = 61.74 Hz for the low B — and a lightly bowed harmonic is a cleaner signal for a small microphone.

Orchestral and jazz setups

The double bass is used in very different musical roles, and the setup follows the job:

• Orchestral basses are usually four-string EADG. Many carry a low-C extension on the E string, a mechanical device that lets the string sound down to C1 = 32.70 Hz when engaged. Some orchestras use five-string basses instead.
• A low-C extension is not one of the preset targets. Tune the E string with the extension closed, or use the chromatic setting to read C1 directly.
• A five-string goes lower than an extension. Its low B0 at 30.87 Hz is below the extension’s C1 at 32.70 Hz.
• Jazz players usually prefer four strings and a lower action. Pizzicato is the main voice, so the setup favours a string that speaks quickly under the finger rather than a long orchestral sustain. A pickup is common.
• Solo tuning is a specialist setup. It raises all four strings a whole step to F#1, B1, E2 and A2 for solo repertoire. It is not the standard orchestral or jazz tuning; if you use it, the chromatic setting can read those pitches.
• Arco and pizzicato behave differently under the microphone. Arco sustains and is the easiest to read. Pizzicato has a strong attack and a fast decay, so the display is only steady early in the note.
• The bass sounds an octave below written pitch. The tuner reports sounding pitch, so a written E2 appears as E1 on the display.

Placing the microphone on a large instrument

• Close is essential. A hand’s width from the bridge or the f-hole area is a good starting point. The low strings lose the most level over distance.
• Aim at the body, not at the player. The instrument radiates from its top and back; the player’s body can block the microphone if you point it across the bass.
• Do not rest the phone on the instrument. Contact with the body picks up handling noise, bow noise and the player’s movements instead of the note.
• A hard floor reflects low frequencies. In a small room, a bare floor and walls reinforce the bottom end; a carpeted room can make the bass sound thinner. Neither changes the tuning, but it changes how easily the microphone hears the fundamental.
• In a section, tune before the room fills. A hall of basses tuning at once is the hardest possible environment for a microphone tuner. Get in early, or tune one instrument at a time.

Accuracy and limits

• Below roughly 50 Hz the reading is approximate. The low E and low B sit there. The detector handles them on the decimated low-frequency path (4x decimation to 11.025 kHz, a 1024-sample window of about 92.9 ms, roughly 1.7 periods of B0), so the limitation is the microphone’s rather than the player’s — small capsules lose sensitivity before the detector runs out of periods.
• A weak fundamental can produce an octave error. The low strings’ harmonics can dominate what the microphone receives, and the display may report the octave above the open string.
• The room’s low-frequency noise competes directly. Traffic, ventilation, footsteps and a heating system all live in the same region as the low E and low B. Very low rumble outside the instrument’s range is rejected rather than shown as a note, but it still masks the string.
• A bass has strong body resonances. One note can sound uneven or louder than its neighbours, and a string near that resonance may refuse to settle. Move to another string and come back.
• New bass strings settle for a long time. The thick low strings stretch over days of playing. Expect to retune repeatedly after a change, especially the low B.
• Temperature and humidity move a bass noticeably. Pegs can slip in dry weather, and an instrument carried into a cold hall arrives flat. Tune after it has settled for a few minutes.
• The open fourths are the ear check. If the display is unsure on the bottom string, playing it against the next open string and listening for a beatless fourth is a reliable confirmation that does not depend on the microphone.

Safety

• Double bass strings carry the highest tension of any string on this site. Tune up in small increments and stop at the target. Never rush a thick string up from slack.
• The bridge is held by string tension and the soundpost by friction. Never remove all the strings at once — on a bass this can let the soundpost fall, which is a luthier’s repair. Change strings one at a time.
• Never force a peg. Bass pegs are large and a pegbox crack is expensive. A peg that will not turn is binding; ease it free.
• Control a slackened string. The low strings are thick and store a lot of energy. When you release one, hold the loose end rather than letting it spring.
• Watch the tailpiece and endpin. Check the endpin is secure and the tailpiece is sound before you pull a string up to pitch; a bass that falls is a serious repair.
• Do not tune the low E an octave high. The target is E1 = 41.20 Hz. An octave above is roughly double the tension the string and instrument are built for.
• Move and hold the instrument safely. A double bass is large and awkward. Use a proper stand or get help rather than balancing it while you tune.
• Protect your hearing. A double bass close to the player produces high low-frequency levels. Take breaks during long sessions.