PDC override

While working with virtual instruments and live input monitored tracks, it is important for audio to be streamed at low latency in order to minimize delay.

Although Sonar supports streaming audio at very low latency, there are cases where internal buffering can cause additional latency. The most common scenario is when using look-ahead plug-ins that require Automatic Plug-in Delay Compensation (PDC). PDC is the process of delay compensating other normal tracks so they are synchronized with the delayed audio produced by the plug-ins.

Whenever delay compensation takes place on a track that has a live input (an input monitored track or synth track), it is delayed by the required amount to synchronize it with other tracks. In some cases, the delay can be noticeable and make live tracking difficult.

The PDC Override toggle lets you disable delay compensation on live tracks, thereby removing the latency during playback and recording of such tracks. Since it's a toggle, you can quickly turn it on to complete your tracking at low latency, and turn it off when finished to hear the track compensated as normal.

Regardless of whether PDC Override is enabled or disabled, recorded audio is placed on the timeline at the correct position as recorded.

PDC Override is ignored during a bounce/export or freeze operations.

Tip: You can control which tracks are delay overridden by enabling input monitoring only for those tracks. For more information, see Input monitoring.

To enable/disable PDC override

To enable/disable PDC override, click the PDC Override button in the Control Bar’s Mix module.

Figure 95. The Mix module.

Delay compensation is enabled/disabled on all live input tracks in the project. All other tracks have normal delay compensation applied.

 

Note: If the live track being monitored also contains track data (or MIDI data in the case of a synth track), the streamed track data will not be delay compensated. As a result the recorded track data will not be in sync with other tracks. You should either mute any clips on the live tracks, work with an empty region of the track, or use an entirely new track while recording.

To selectively override PDC for playback, recording, or both, long press or right-click the PDC Override button and select the desired options:

Override during playback. If this option is disabled, PDC Override will not affect tracks with input echo during playback.

Override during recording. If this option is disabled, PDC Override will not affect tracks with input echo during recording.

Both are enabled by default. If both are disabled, PDC override is still in effect during idle input monitoring.

Some signal routings can cause tracks to be out of sync when PDC Override is enabled. To prevent any potential sync problems, follow these suggestions:

Output the live input tracks directly to the final bus in the signal flow.

Send live tracks directly to a hardware main.

PDC re-sync

Some plug-ins, such as iZotope Ozone 4 and various UAD plug-ins, change their internal delay (PDC) dynamically when certain parameters are modified, presets are changed or internal plug-in routing is changed. When a plug-in changes its internal delay, Sonar will detect this and re-sync all tracks in the project to this new delay value. While this is done you may hear a momentary interruption in playing audio. This is normal and required in order to keep tracks in sync and delay compensated.

 

See also:

Input monitoring

Arming tracks for recording