Double Tracking vs Copying
A-Level Music Technology | 1.4 Sampling | A* Extension
⚠️
EXAMINER WARNING (2022-2024)
"Merely copying vocal to another track just adds level - doesn't sound like separate vocal."
This error has appeared in examiner reports for three consecutive years.
❌
WRONG: "Just copy the track"
This is what students write - and lose marks every year
Original Vocal
Copied (IDENTICAL)
Same waveform!
Why this fails: Identical waveforms = constructive interference = just LOUDER (+3-6dB). No timing variation. No pitch variation. Sounds like ONE louder voice, not TWO voices.
✓
CORRECT: Timing + Pitch Variation
The waveforms must be DIFFERENT - either naturally or via ADT
Original Take
Second Take (VARIED)
Why this works: Natural timing variations (5-20ms) + pitch variations (5-20 cents) create the chorus-like thickening effect. The brain perceives TWO performances.
Three Approaches Compared
| Approach | Works? | Why? |
|---|---|---|
| True Double (2 takes) | ✓ | Natural timing/pitch variation |
| ADT (processed) | ✓ | Artificial timing/pitch variation |
| Copying | ✗ | Identical = louder only |
⚠️The Common Mistake - Why Copying Fails
COPYING DOES NOT CREATE DOUBLE TRACKING
When you copy a track and layer it:
• Every sample is IDENTICAL
• Identical waveforms = constructive interference
• Result: +3 to +6dB louder, but sounds like ONE voice
EXAMINER QUOTE (2022-2024):
"Merely copying vocal to another track just adds level - doesn't sound like separate vocal."
When you copy a track and layer it:
• Every sample is IDENTICAL
• Identical waveforms = constructive interference
• Result: +3 to +6dB louder, but sounds like ONE voice
EXAMINER QUOTE (2022-2024):
"Merely copying vocal to another track just adds level - doesn't sound like separate vocal."
⭐What Makes Double Tracking Work
TWO ELEMENTS MUST VARY:
1. TIMING VARIATION (5-20ms difference)
- Creates width and space
- Falls within Haas Effect threshold (under 40ms)
2. PITCH VARIATION (5-20 cents difference)
- Creates chorus-like thickening
- Below perception threshold for detuning
These variations make the brain perceive TWO separate performances.
1. TIMING VARIATION (5-20ms difference)
- Creates width and space
- Falls within Haas Effect threshold (under 40ms)
2. PITCH VARIATION (5-20 cents difference)
- Creates chorus-like thickening
- Below perception threshold for detuning
These variations make the brain perceive TWO separate performances.
Key Rules to Remember
1
COPYING = LOUDER, NOT DOUBLED
Identical waveforms sum = constructive interference
2
TIMING + PITCH VARIATION = THE KEY
Both must vary to create double-tracking effect
3
ADT: DELAY 10-40ms + PITCH +/-5-20 cents
Short delay (Haas zone) + subtle pitch modulation