About BassTuner.io
How the low-frequency pitch meter, reference calculations, microphone privacy, setup limits, and correction process work.
Purpose and Scope
BassTuner.io is a bass-specific pitch tool and reference library for 4-, 5-, and 6-string instruments. It combines microphone tuning with documented open-string targets, an adjustable frequency calculator, a step-by-step workflow, and troubleshooting for low-frequency detection, string stability, alternate tunings, and intonation. The aim is to help a player understand the reading, not simply display a green meter.
What the Tuner Measures
After microphone permission is granted, the tuner estimates the strongest repeating frequency in the audio and compares it with the selected open string. It reports the difference in cents using an autocorrelation-based detector. Samples are processed on the device; BassTuner.io does not intentionally record or upload microphone audio.
Frequency Method and Low-Note Limits
A440 targets use 12-tone equal temperament: frequency equals 440 × 2(n − 69) / 12, where n is the MIDI note number. Standard E1, A1, D2, and G2 are 41.20, 55.00, 73.42, and 98.00 Hz. The frequency reference applies the same formula to A4 values from 415 through 445 Hz.
Device microphones often capture bass harmonics more strongly than B0 or E1 fundamentals. Plucking force, pickup tone, room noise, speakers, string condition, and fret buzz can also move or confuse a reading. The guide explains how to confirm the octave and when a cable or clip-on tuner is a better measurement path.
What a Pitch Meter Cannot Diagnose
A microphone cannot inspect string gauge, post windings, nut slots, scale length, neck relief, action, bridge hardware, or saddle position. It also cannot determine whether a very low tuning is appropriate for a particular bass. Those factors affect stability, buzz, feel, and fretted-note intonation even when an open string is exactly on target. Persistent mechanical problems should be evaluated by a qualified repair person.
Ownership, Review, and Corrections
John Sorrentino created and maintains BassTuner.io as part of a collection of focused browser tools. Tuning targets, preset names, pitch calculations, and educational pages are reviewed when the detector or reference library changes. The site is independent and is not a substitute for an experienced teacher, bass technician, or instrument maker.
If a note, octave, frequency, preset, or instruction appears wrong, use the contact page and include the page, bass/string count, selected tuning, device, browser, displayed result, and expected result. Reproducible corrections take priority over adding more presets.