A millisecond score is only useful if you know what clock it is measuring against. TempoLock keeps audio output timing and tap-input correction separate so that a Bluetooth delay is not mistaken for a player timing error.
The basic idea
TempoLock schedules musical events on an audio timeline, then compares each relevant tap with the expected beat on that same timing model. The app uses the browser audio output clock when it is available and falls back when the browser does not expose the same timing information.
The beat you are scored against never moves because a screen animation or a Bluetooth route is slow.
Audio Output and Tap Input are different corrections
Moves when the click is scheduled to reach the output route. TempoLock’s Normal/Bluetooth presets affect the click audio; they do not move the visual target or scoring beat.
Applies a small correction to the timestamp used for your tap. It is intended for repeatable input/device offset, not for compensating for an obviously late Bluetooth click.
Keeping these controls separate matters. If Bluetooth makes the sound arrive late and the app instead moved the scoring target, the game could appear “correct” while teaching you to tap against the wrong reference.
What the main result metrics mean
| Metric | Meaning |
|---|---|
| Early / late error | How far a tap landed before or after its expected beat. |
| Average error | The typical absolute distance from the expected beat across the run. |
| Consistency | How tightly the taps cluster rather than whether they are all shifted in the same direction. |
| Final drift | How far the timing has moved by the end of a run where accumulated drift is meaningful. |
| Aim / recall quality | Mode-specific information used alongside timing in Tempo Aim and Echo Chain. |
Bluetooth: why it can feel wrong even when the browser is “on time”
Bluetooth audio is buffered. The browser may know exactly when it handed audio to the output system while you hear that sound later through the wireless route. The delay can also change between headphones, codecs, operating-system states and browser sessions.
That is why TempoLock has a separate Audio calibration and saved Normal/Bluetooth presets. If the click itself sounds late, fix the audio route first. Only use Tap Input correction for a remaining repeatable difference in the tap timestamp.
What calibration does
Tap calibration asks for a set of clean, even taps and rejects a run that is too inconsistent to estimate a useful offset. The current correction range is ±100 ms. Larger corrections are saved, but TempoLock prompts you to check Audio Output first because a very large apparent tap offset can actually be an output-delay problem.
Why browser timing still has limits
TempoLock runs in ordinary browsers across phones and computers, so it cannot control every audio driver, Bluetooth codec, power-saving decision or touch-stack delay. It is not lab equipment. The aim is a measurement that repeats on the same setup and is open about what can throw it off.
Calibrate each setup you use
If you switch from phone speakers to Bluetooth earbuds, treat that as a different audio route. Keep Normal for the direct route and Bluetooth for the wireless one. Recheck calibration if a device or browser update makes the click feel obviously different.
Compare runs on the same setup
Scores mean most when you compare repeated runs and look for patterns in the error.
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