Latency and Delay Compensation overview
- Live Versions: Live 9.2 and later
- Operating System: All
What is Latency?
Audio Latency refers to a short period of delay (usually measured in milliseconds) between when an audio signal enters and when it emerges from a system. In computer based audio systems a certain amount of latency, known as audio buffering, is necessary to ensure that playback, recording and processing results in an error-free audio stream without dropouts or glitches.
In addition certain devices, plug-ins and processes introduce latency. Live has a built in option called Delay Compensation which compensates for this.
In this guide we'll discuss various causes of latency and how to deal with it.
- Latency due to the audio buffer
- Live's Delay Compensation
- Checking the latency of a device
- Which elements are compensated and which are not
- Reducing latency when monitoring
- When to use Driver Error Compensation
Audio buffering ensures audio can be played back while minimising glitches or dropouts. With an audio buffer of 256 samples, a chunk of audio 256 samples long is processed. The interface then fetches the next batch of 256 samples, and so on. Note the following tips:
- Smaller buffer sizes reduce latency
However a buffer size too small may cause dropouts or glitches due to the increased CPU load. Find the sweet spot where the buffer is as small as possible without impairing the audio quality.
- Higher sample rates reduce latency
Sample rate refers to the amount of samples which are carried per second. The higher the sample rate, the lower the latency. Higher samples rates will also put additional stress on the CPU.
These tips might help you achieve lower buffer sizes:
- Use a dedicated audio interface rather than the computer's built in soundcard
- On Windows, use ASIO rather than MME/Direct X as the driver type
- If no native ASIO driver is available for your device use ASIO4ALL instead
- Reducing the CPU load may allow you to work at lower buffer sizes
In Live's Preferences → Audio, the overall latency is calculated according to the buffer size and sample rate in use.
In addition to the latency caused by the audio buffer and sample rate, certain devices, plug-ins, and track delays can introduce latency. These latencies or delays arise from the time taken by devices to process an input signal and output a result.
- Negative Track Delays: Using a negative track delay on one track causes all other tracks to be delayed accordingly. The amount of negative track delay is added to the Overall Latency amount in Live's preferences
- External Instrument and External Audio Effect: As these devices send and/or receive audio from outside Live, they will delay the audio by the Overall Latency amount in preferences. In addition, when setting the 'Hardware Latency' slider to any amount other than zero, this will add extra latency.
- Ableton Devices, third-party plugins or Max for Live Devices: Any of these devices which use oversampling or convolution algorithms can add latency.
- Devices using "lookahead": Dynamic processors often come with a "lookahead" feature, which introduces a negative delay on the sidechain signal to allow the gain reduction to catch fast transients more effectively.
Live's Delay Compensation automatically compensates for the latencies caused by devices, plug-ins, and track delays. The compensation algorithm offsets each track by the required amount to keep them in perfect sync with each-other. Delay compensation is on by default and doesn't need to be adjusted in any way. If required, it can be manually turned off or on using the "Delay Compensation" option in the Options menu.
Hover your cursor over a device title bar in Device View to display its latency in the status bar. Note: If Delay Compensation isn't active then it won't display anything.
Further reading - Ableton devices which introduce latency.
As of Live 9.2, audio, automation, and modulation are fully compensated.
Graphics Elements are not compensated, thus level meters, video playback and other graphic elements might be displayed slightly ahead of time with respect to the audio.
Built-in device modulation which is synced to the Live transport (i.e., synced to a specific beat-time position) is not compensated. One example would be the Auto Filter LFO (in Sync mode), which might be slightly off depending on the position the device has in the effect chain. Specifically, if the Auto Filter is located after a number of devices introducing a large latency, the modulation might be offset to an earlier position with respect to the grid. Note that this does not happen to all Ableton Devices relying on Live's tempo information, but rather only to those which sync to a specific song position. For example, Ping Pong Delay, Filter Delay, and Simple Delay do not present the problem and are always correctly compensated.
Return tracks are not compensated when routed back to an audio track if the respective Send on the destination track is active. To restore the correct delay compensation for Return tracks routed to Audio tracks, disable the respective sends. You can disable a send by right clicking on the Send knob and choosing "Disable Send". For example, if you route Return Track A to Audio Track 1, right click on Send A on Track 1 and choose "Disable Send" to restore the correct latency compensation.
When large negative delays are in use, or if a number of latency-inducing plugins cause the overall latency to become quite large, it might become impossible to record audio or MIDI in real time. This is especially problematic if you're monitoring through Live. There are a number of ways of dealing with this.
Use the "Reduced Latency When Monitoring" option
Activate "Reduced Latency When Monitoring" from the Options menu. This bypasses the additional latency in tracks which are either record-enabled or whose Monitoring is set to "In".
For detailed information on this option, see our dedicated article on Reduced Latency When Monitoring.
Use Direct monitoring (If your audio interface supports it)
Some audio interfaces have a function called direct monitoring, which allows near-zero latency. The live signal enters the interface and is routed back out through the headphone monitor mix, instead of passing through the DAW first. You can send a copy of the signal into Live in order to record it at the same time.
Monitor through an external mixing desk
Instead of monitoring through your interface or Live, monitor through an external mixing desk. At the same time, send a copy of the signal into Live in order to record it.
Some audio interfaces (for instance class-compliant devices) don't report an accurate device latency to Live, resulting in recorded audio which may be slightly mis-aligned. Driver Error Compensation allows you to compensate for this mis-alignment. Note: Driver Error Compensation is only applied to recording tracks when the monitor is set to "Off". For more information see our dedicated article When to use Driver Error Compensation.
Important: It's only necessary to use Driver Error Compensation if you have an interface which requires it. Changing the Driver Error Compensation field is not a solution for general latency issues in Live.