Published by PitchChanger · Updated · How these guides are made
Hear the difference
Original synthesized diagnostic material, authored at 48 kHz, 16-bit PCM. These are controls for the worksheet, not measurements of this tool or real instruments.
Pause your workspace preview before comparing these clips.
Start quietly. Download the WAV files for external comparison; no listening outcome is asserted.
How to use this workflow
Find a known boundary
Choose a sharp event preceded by a quiet interval. Check the source before exporting another version.
Keep alignment explicit
Match the event onset, accounting for any trim or speed change. Inspect the saved result rather than the filename or waveform thumbnail.
Repeat at a fixed level
Listen to a short interval before and through the event. Record what changes and whether the observation repeats.
A deliberately added 50 ms pre-event signal
Attack is zero before the 1.000 s onset. Pre-event adds a low-amplitude 1 kHz tone from 0.950 s up to, but not including, 1.000 s. At 48 kHz, that interval spans 2,400 sample frames. The added component has nominal amplitude 0.03 versus the main attack’s 0.5 envelope.
The added tone is a pedagogical control, not codec-generated pre-echo, and its abrupt boundary is part of its construction. The envelope ratio is 0.03 / 0.5 = 0.06, or about −24.437 dB. This does not predict audibility or an encoder’s behavior.
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| Checkpoint | Action or value | Interpretation |
|---|---|---|
| 0–0.950 s | Both controls zero | Known quiet region |
| 0.950–1.000 s | Added tone only in Pre-event | 2,400 frames |
| 1.000 s onward | Same damped attack | Align this landmark |
Do not diagnose from a picture alone
If the suspicious sound occurs only after the attack, it is not pre-onset energy. Ringing, reverb and a source’s existing ambience need separate descriptions. If it appears only at a cut boundary, check fades and selection accuracy before blaming encoding.
Audio Converter can make format variants but has no pre-echo analyzer. Retain a lossless source, compare matched versions externally and document the exact passage. These controls demonstrate a location in time, not a product quality score.