Tuning a bass by ear at these frequencies
Low fundamentals make beats easier to hear, not harder - when your E string and the 41.2 Hz reference are 1 Hz apart, you hear a slow, obvious pulse once per second. Tune until the pulse slows to nothing. If your playback gear cannot reproduce the fundamental, tune to the harmonics you can hear: the beating works identically.
A trick that sidesteps speaker limits entirely: tune your G string (98 Hz - every speaker handles that) to the reference, then tune the remaining strings to each other using the 5th-fret method - the note at the 5th fret of one string equals the next open string.
Keep your intonation honest
- Tune with the tone control open and pluck near the neck for a cleaner fundamental.
- Fresh roundwound strings ring sharp for the first minutes of playing - stretch and re-tune.
- Always tune up to pitch; a bass string tuned downward will sag flat under playing tension.
- Check tuning at the 12th fret too: if the octave is sharp or flat while the open string is right, your intonation (saddle position) needs adjusting, not your tuning.