为什么在Pro Tools中使用Send/Return插件与DAPS通讯时，轨道之间会有延迟？

在Pro Tools中使用杜比全景声Send和Return插件会产生音频同步和延迟问题。你需要采取以下步骤来避免音频在和渲染器往返时产生的同步问题（扬声器信号或Re-render输出都是从渲染器返回的）

  1. 所有渲染器的输入（所有送往Send插件的音频路径）需要有同样的延迟时间，您可以使用无延迟的插件或在所有轨道上做相同的插件设置。

    • Send插件会在Pro Tools进行延迟补偿之前将音频发送到全景声渲染器。因此，如果各个输入通道有不同的延迟时间，无论将Send插件直接挂在音频轨道上还是辅助轨道上，那么他们会在没有延迟补偿的情况下在渲染器中混合。

  2. 所有渲染器的输出（所有包含Return插件的音频路径）应该为他所在辅助轨道的输入设置一个“假”总线，并且该轨道上不插入任何插件。

    • 如果某个输出上有插件造成的延迟，那么Pro Tools会应用延迟补偿，这样会形成相对于其他轨道输出的延迟问题。

  3. 播放引擎中的“Dynamic Processing”（动态处理）功能需要关闭。

    • 在动态处理开启时，Pro Tools会将没有输出音频的轨道上的插件不激活，这样造成Send/Return插件不运行，引发某些声音缺失或错位。

  4. 在使用HDX硬件时，Send/Return插件应该使用DSP模式。如果使用了Native模式，那么Native和DSP两种模式的信号将不能混合，因为他们具有不同的延迟时间。

    • Send/Return插件在Native和DSP两种模式下有不同的延迟特性，因此将他们混合在一起会造成声音错位。

Why do I hear latency between tracks using the Production Suite in Pro Tools with send/return plugins?

Using the Doing Atmos Renderer Send and Return plugins in Pro Tools can produce audio alignment and latency issues. The following steps should be taken to avoid alignment issues between audio input to the renderer and/or outputs from the renderer (speaker or re-render outputs).

  1. All renderer inputs (that is, any audio path prior to a Send plugin) should have the same latency: either with zero-latency plugins or with the same plug-ins inserted on all tracks.

    • the Send plugins routes audio to the Atmos Renderer ahead of automatic delay compensation in Pro Tools. If different inputs have different latencies they will be mixed together in the renderer without any type of compensation. Note that this is regardless of inserting the Send plugin directly in a track or indirectly in an Aux bus.

  2. All renderer outputs (that is, any audio path containing a Return plugin) should be use a dummy bus as the aux track input and no plugins should be used/inserted on the track.

    • If an output has plugins with reported latency of the output, Pro Tools will apply latency compensation which will result in latency vis a vis other outputs.

  3. Dynamic processing should be disabled in the Playback Engine settings.

    • When dynamic processing is enabled, Pro Tools may not activate Send or Return plugins that sit in “dead paths” in terms of Pro Tools. Not executing Send or Return plugins can cause problems such as muted signals and misalignments.

  4. When using HDX hardware, all Send and Return plugins should be DSP. If Native versions are used, Native and DSP cannot be mixed as they have different latencies.

    • Send/Return plugins have different inherent latencies in Native and in DSP implementations. Mixing them will result in alignment issues.