Work with plug-in latencies in Logic Pro for Mac

All plug-ins cause timing delays, known as latency, when processing audio. Small delays are not audible; however, the more processor-intensive a plug-in is, the bigger its latency will be. Those latencies can cause timing issues when playing back your project or when recording new tracks in your project. Logic Pro provides two types of settings, plug-in latency compensation and Low Latency Monitoring mode, that can solve those issues.

Plug-in latency compensation

In a project, different channel strips often have different plug-ins, resulting in a different overall latency for each channel strip. Some channel strips might also be routed to aux channel strips via sends containing plug-ins that could add even more latency. However, you can compensate for those latencies using plug-in latency compensation to ensure that the audio output is perfectly synchronized. Logic Pro detects the channel strip with the maximum latency, and delays the other channel strips in real time by an individual amount so that they all play back in sync. You can choose from three options for plug-in latency compensation: delaying the regions on individual tracks, delaying the audio signal on individual channel strips, or no latency compensation.

When plug-in latency compensation is turned on, there can be a slight lag between the moment you start playback and the moment the tracks start to play in sync, depending on the amount of latency being compensated.

Note: Plug-in latency compensation also applies to automation data and signals used in side-chain routing.

Figure. Help tag showing plug-in latency.

Tip: Move the pointer over a plug-in slot to show a help tag with the latency of that plug-in in samples and seconds (sec).

Low Latency Monitoring mode

When you sing into a microphone or play a MIDI keyboard, you hear your signal delayed when monitoring through a track that contains high-latency plug-ins or when the track is routed to aux channel strips with high-latency plug-ins in their signal path. This makes it difficult to perform with proper timing when recording on such a track. Instead of manually turning off the plug-ins on the track you are about to record, you can turn on Low Latency Monitoring mode; and Logic Pro automatically bypasses latency-inducing plug-ins that exceed a specific latency value and turns off any Aux sends on that track. See General Audio settings.

Low Latency Monitoring mode only affects the focused instrument track and any tracks on which the Input Monitoring or Record Enable buttons are active. The following happens on those tracks:

A plug-in is bypassed when its latency pushes the track’s total latency value above the set limit, and its plug-in button changes to gray with an orange text label.
Audio effect plug-ins with low latency are unaffected and remain active (blue button).
Every Send slot is turned off, and their Send button changes to gray with an orange text label.
A new “Low Latency Safe” option is available in the Send slot shortcut menu.
When this is selected, the Send slot remains active, which is useful when you’ve routed the track’s signal to a reverb that you want to hear during recording.

Note: Focused instrument tracks show the bypassed slots once you start the playback.

Figure. Send slot shortcut menu showing Low Latency Safe menu item.

Important: In addition to the plug-in latencies, there are other components that introduce latencies. For example, MIDI controllers connected via Bluetooth, the input and output stage of your selected audio interface, or the I/O Buffer Size value. For details, see Audio Devices settings.

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 only audio or software instrument channel strips contain latency-causing plug-ins, choose this option. During playback, Logic Pro automatically shifts the regions on the individual tracks in real time to keep the audio output of all corresponding channel strips synchronized.
All: If aux or output channel strips also contain latency-causing plug-ins, choose this option. During playback, Logic Pro delays the audio streams of each channel strip individually to keep them all synchronized.

Tip: Use the key command Set Plug-in Latency Compensation Mode to switch between “All” and “Audio and Software Instrument Tracks.”

Turn Low Latency Monitoring mode on or off

In Logic Pro, do one of the following:

Click the Low Latency Monitoring Mode button in the control bar.
Note: By default, the Low Latency Monitoring Mode button does not appear in the control bar. To add this button to the control bar, see Customize the control bar.
Click the Low Latency Monitoring Mode checkbox in Logic Pro > Settings > Audio > General.
Use the key command Toggle Low Latency Monitoring Mode.

When you activate Low Latency Monitoring mode, the Limit slider in Logic Pro > Settings > Audio > General lets you determine the maximum amount of allowed latency across the entirety of the current track’s signal path (up to 30 ms). See General Audio settings.

WARNING: The sound may change when you turn on Low Latency Monitoring 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. Low Latency Monitoring mode is inactive when you bounce your project.

Reactivate a Send slot in Low Latency Monitoring mode

With Low Latency Monitoring mode activated, all Send slots on a record-ready channel strip are turned off, indicated by their gray buttons with orange text.

In Logic Pro, show the Mixer.
On the record-ready channel strip, click the Send slot you want to reactivate, then choose Low Latency Safe from the shortcut menu.
The Send button changes to blue.

To deactivate the Send slot again, click the Low Latency Safe option in the shortcut menu to deselect it.

Download the guides:

Logic Pro User Guide: PDF

Logic Pro Instruments: PDF

Logic Pro Effects: PDF

Control Surfaces Support Guide: PDF

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Logic Pro User Guide for Mac