Work with plug-in latencies in Logic Pro for Mac

Some plug-ins may cause small timing delays, known as latency, when processing audio. This processing can take the form of input latency, output latency, or both. For example, playing a software instrument in Logic Pro incurs only an output latency because the instrument’s audio is generated by the application. However, monitoring an audio recording may have both an input and an output latency because the signal must be input into Logic Pro before it can be processed. Input latency (if any) is added to the output latency, resulting in an overall monitoring latency. Each further process—such as the use of insert effects, for example—may add to the overall monitoring latency. However, Logic Pro can compensate for these latencies using plug-in latency compensation to ensure that all your audio output is perfectly synchronized.

You can turn plug-in latency compensation on or off. When plug-in latency compensation is turned on, there can be a slight lag between the moment you start playback and the moment when output begins, depending on the amount of latency being compensated.

In Logic Pro, you can choose to apply plug-in latency compensation either to all channel strip types, or to only audio and software instrument channel strips:

Audio and software instrument channel strips only: If you insert latency-causing plug-ins only on audio and instrument channel strips, you can choose plug-in latency compensation for only audio and instrument tracks. Logic Pro achieves this by delaying audio and MIDI regions on audio and instrument tracks. This results in snappy playback performance.
All channel strip types: If you insert latency-causing plug-ins on aux or output channel strips, you can choose plug-in latency compensation for all types of channel strips. When this setting is turned on, Logic Pro for Mac compensates for latency-causing plug-ins by calculating the amount of latency caused by all plug-ins, and then delaying audio streams by an appropriate amount. This type of plug-in latency compensation can result in a slight lag in playback performance, depending on how much latency is being compensated.

If you use latency-causing plug-ins, it’s best to apply them only after you finish recording. Delays in playing back audio, whether caused by a plug-in or by the plug-in latency compensation feature, can result in your performance being out of time. However, if you find that you need to do additional recording after you have inserted latency-causing plug-ins into your mix, you can activate Low Latency Monitoring, which will route your audio around any latency-causing plug-ins, so that the recorded audio isn’t delayed.

To determine if a plug-in causes latency, see the documentation for the plug-in.

When Enable Complete Features is selected in Logic Pro > Settings > Advanced, plug-in latency compensation and Low Latency mode are available.

Turn on plug-in latency compensation

In Logic Pro, choose one of the following options from the Compensation pop-up menu in Logic Pro > Settings > Audio > General:
- Audio and Software Instrument Tracks: If you have inserted latency-causing plug-ins only into audio or instrument channel strips, choose this option. Logic Pro automatically shifts audio and MIDI regions in time to keep all the output synchronized.
- All: If you have inserted latency-causing plug-ins into aux or output channel strips, choose this option. Logic Pro delays all audio streams by an appropriate amount to keep them all synchronized with each other.

Turn on Low Latency Monitoring mode

In Logic Pro, do one of the following:

Click the Low Latency Monitoring button in the control bar.
Note: The Low Latency Monitoring button does not appear in the control bar by default. To add this button to the control bar, see Customize the Logic Pro for Mac control bar.
Select the Low Latency Mode checkbox in Logic Pro > Settings > Audio > General.

Recorded audio is routed around any latency-causing plug-ins in the signal path. This ensures that the maximum delay that can occur across the signal flow (that is, across the entirety of the current track’s signal path) is less than the latency value you set using the Limit slider in Logic Pro > Settings > Audio > General.

When Low Latency Monitoring is turned on, the text labels of plug-ins that are bypassed for latency reduction appear orange in channel strips for which Input Monitoring is active.

The sound may change when you turn on Low Latency mode. Depending on the plug-ins in use, the change in sound can be anything from subtle to dramatic. If plug-ins being used do not exceed the total latency limit, there is no audible difference.

Download the guides:

Logic Pro User Guide: PDF

Logic Pro Instruments: PDF

Logic Pro Effects: PDF

Helpful?

Logic Pro User Guide for Mac

Work with plug-in latencies in Logic Pro for Mac

Turn on plug-in latency compensation

Turn on Low Latency Monitoring mode