What we tested
We generated three 22,050 Hz, 16-bit stereo WAV files. C4 and G4 existed only in the left channel; E4 and C5 existed only in the right. Each note lasted 0.900 seconds, with a 0.300-second silent gap. No public or named media was used.
The left-channel level stayed fixed. The right channel was balanced, reduced by 12 dB, or reduced by 24 dB. Pitch, note timing, waveform, envelopes, sample rate, converter controls, and converter code stayed fixed.
| Right-channel level | Right-channel RMS | MIDI events | Right-only notes |
|---|---|---|---|
| Balanced | 0.23474 | 6 | E4 at velocity 83; C5 at 77 |
| -12 dB | 0.05897 | 5 | E4 at velocity 60; C5 at 57 |
| -24 dB | 0.01481 | 5 | E4 at velocity 41; C5 at 40 |
The quiet-side notes remained in this test
All three outputs contained C4, E4, G4, and C5. The balanced source produced six events in a 105-byte MIDI file because C4 and E4 each had a short same-pitch tail. Both attenuated sources produced five events in 97-byte files; only the C4 tail remained.
Right-side MIDI velocity followed the level change
The main E4 velocity moved from 83 when balanced to 60 at -12 dB and 41 at -24 dB. C5 moved from 77 to 57 and 40. The left-only C4 main event stayed at velocity 83 in every output, while the left-only G4 stayed at 80.
The converter mixes stereo audio to mono before note analysis. Reducing one channel therefore reduces the analyzed level of material found only on that side. This test shows the resulting output for these files; it does not prove that every quiet-side note will survive.
Note duration also moved
The main E4 duration was 0.837 seconds when balanced, 0.872 seconds at -12 dB, and 0.814 seconds at -24 dB. C5 measured 0.919, 0.860, and 0.791 seconds. A quieter channel changed more than velocity in this controlled run.
What to do with an uneven stereo source
- Listen to each channel separately. Check whether the part you need is much quieter on one side.
- Make a working copy. Balance or isolate the relevant channel without overwriting the original audio.
- Compare MIDI drafts. Review pitches, note lengths, velocities, and short fragments instead of judging only whether a note exists.
- Rebuild panning later. The exported MIDI does not preserve the source's stereo position.
Limits of this result
These inputs used isolated sine tones with no overlap, noise, effects, or moving pan. The test does not establish a minimum detectable channel level or predict dense music. It records three exact outputs from the current local converter at default controls.
For channel placement and MIDI pan data, see the stereo preservation test. For timing differences between otherwise identical channels, see the stereo delay test.