Ableton/Live/UG/39 Audio Fact Sheet/02 Neutral Operations
- A neutral operation leaves the audio unchanged. Recorded audio stays identical to what the A/D converter delivered, imported files stay identical to the files on disk, and an export is at least as good as what played back.
- Neutral operations usually happen alongside non-neutral ones. Any neutral step that follows an effect or a gain change still carries that change.
- Export Audio/Video is neutral when the file's sample rate matches the audio hardware rate in Live's Settings and no non-neutral operation was applied.
- Ableton's phase-cancellation tests rendered white noise, sine waves and sine sweeps at 16, 24 and 32 bits:
- Same or higher bit depth than the original: complete cancellation.
- Lower bit depth: the smallest distortion a 32-bit system allows.
- An unstretched file plays back neutrally when its sample rate matches Live's Settings and it is not transposed. This covers audio inside Live only, before it reaches the audio hardware.
- A clip at the Set's tempo plays unstretched. In Beats, Tones, Texture or Re-Pitch Warp modes that playback is neutral; Complex and Complex Pro are not.
- Tempo changes stretch only while they last. Tracks recorded at 120 BPM play back neutrally again once the tempo returns to 120 BPM.
- Arrangement tempo automation in Beats mode with transient preservation can cause artifacts. Preserving 16ths or using Re-Pitch avoids them.
- Grooves move Warp Markers, so a clip with a groove is never neutral, even at its original tempo.
- Live sums signals in 64-bit double precision at every mix point: clip and return track inputs, the Main track and Racks. Mixing at a single point is therefore neutral.
- Internal processing stays 32-bit, so a signal mixed across several summing points can lose a very small amount of quality.
- Recording an external signal is neutral when the bit depth in Live's Settings is equal to or higher than the A/D converter's. Neutral here means identical to what the converter delivered.
- Recording through internal routing is neutral at 32 bits. Use 32 bits for plug-in instruments and effected signals.
- A source that is already at a lower bit depth records neutrally at that depth; recording a 16-bit file at 32 bits adds no quality.
- Freeze writes 32-bit files, so frozen audio is no worse than what played before freezing. Some cases still change the result:
- Frozen Session View clips are two loop cycles long, so longer tails get cut off. Arrangement View freezes keep tails past the clip end.
- Frozen reverb and delay tails stop abruptly when playback stops, because they are rendered audio.
- Frozen Arrangement clips include their automation. Frozen Session clips keep the parameter values found at the Arrangement's 1.1.1 position.
- Frozen clips always play with Warp on in Beats mode.
- Random device parameters, such as Beat Repeat's Chance, stop being random after freezing.
- A bypassed effect is taken out of the signal flow, for Live's devices and for VST and AU plug-ins alike, so its output equals its input.
- Devices with built-in delay, such as Compressor's Lookahead, keep that delay while bypassed so delay compensation stays correct.
- Routing a signal is neutral: the destination receives the same signal the source sends.
- Tapping a signal partway through a chain, such as before a track's effects or from a single Impulse sample slot, gives a different signal than the end of that chain.
- Splitting a neutral clip keeps it neutral. A split changes only the playback position in the sample, and playback across the split has no gap and is sample-accurate.
- Ableton tested unwarped clips and warped-but-unstretched clips, with loop on and off, against unsplit renders.