Pro Tools provides a preference for MIDI offset that lets MIDI and Instrument tracks play back earlier or later (than audio tracks) by the specified number of samples. The offset affects playback only and does not alter in any way how MIDI data is displayed in the Edit window.
This capability is provided in large part to compensate for the audio monitoring latency in host-based Pro Tools. If you are monitoring the output of external MIDI instruments with an external mixer or sound system (or headphones), there is no latency. If, however, you are monitoring the output of your MIDI devices through a Pro Tools interface (such as 003 family devices), your MIDI tracks sound slightly later than your audio tracks. The larger the setting for the
H/W Buffer Size (128, 256, 512, or 1024 samples), the larger the latency.
By configuring the Global MIDI Playback Offset setting, you can align your MIDI tracks to play back slightly earlier (by a specified number of samples), thereby compensating for any latency when monitoring audio in Pro Tools host-based systems.
To allow for monitoring latency in Pro Tools host-based systems, set the offset to a value that is roughly equivalent to the
H/W Buffer Size.
You can offset individual MIDI and Instrument track offsets in Pro Tools to compensate for delays in MIDI devices (the time it takes to trigger events on a sampler or synth).
For example, if you have some kick drums that are being played by an audio track in Pro Tools and want them to be exactly synchronized with kick drums that are being played by a MIDI device, you may need to use a MIDI offset. In this example, it will usually take at least 5 ms to trigger the MIDI notes, and it could take even longer, depending on the MIDI device.
You can measure the latency for a MIDI device assigned to a MIDI track by recording its audio output back into Pro Tools. Compare the sample locations for the recorded audio events against the original MIDI notes to calculate the latency.
2 Click in the Sample Offset column for the MIDI or Instrument track and enter the number of samples (–10,000 to 10,000) for the offset. A negative value causes the MIDI or Instrument tracks to play back earlier than the audio tracks; a positive value causes the MIDI or Instrument tracks to play back later.
The equivalent offset in milliseconds is displayed in the msec Offset column. This value cannot be edited, but updates when a new value is entered in the Sample Offset column.
To reset all offsets for all MIDI and Instrument tracks, click the
Reset button in the upper left of the window.