There seems to be errors in the current “CUBASE PRO 9 Operation Manual” regarding both “Constrain Delay Compensation” and “Delay Compensation Threshold”. Since the manual is independent of computer, operating system, etc. I didn’t think it was necessary to provide that information – right? Here are the pertinent details.
From page 646 of the Cubase 9 Operation Manual
“Constrain Delay Compensation
To avoid Cubase to add latency when you play a VST instrument in realtime or record live audio, you can activate Constrain Delay Compensation. This minimizes the latency effects of the delay compensation, while maintaining the sound of the mix as far as possible.”
Based on the following description (and reality) it may minimize the latency effects of VST Plug-ins (rather than delay compensation – which actually doesn’t increase monitoring latency)? 
“Constrain Delay Compensation is available on the Project window toolbar and in the Transport zone. You can also find it as a menu item in the MixConsole on the Functions menu. Activating Constrain Delay Compensation turns off VST plug-ins which are activated for VST instrument channels, audio track channels that are record-enabled, group channels, and output channels. VST plug-ins which are activated for FX channels are disregarded. After recording or using a VST instrument Constrain Delay Compensation should be deactivated again in order to restore full delay compensation.”
Since “Constrain Delay Compensation” really does this, wouldn’t “Turn Off VST Plug-ins that exceed the Plug-in Delay Threshold" (now improperly called “Delay Compensation Threshold”)" be a more appropriate name for that function?
From page 1103 of the Cubase 9 Operation Manual
“Delay Compensation Threshold (for Recording)
“Cubase features full delay compensation - any delay inherent in the VST plug-ins you use will automatically be compensated for during playback. However, when you play a VST instrument in realtime or record live audio (with monitoring through Cubase activated), this delay compensation may result in added latency.”
Delay compensation adds delay to tracks as necessary to ensure that all tracks are in sync during playback regardless of differences in their individual VST plugin delays. As currently implemented (Version 9.0.10), it delays record and playback (i.e. the virtual tape transport) by that experienced by the most delayed track. Other than that, It doesn’t impact the latency experienced by the performer (which is relative to virtual tape transport) while monitoring through Cubase.
“To avoid this, you can click the Constrain Delay Compensation button on the toolbar or the Transport zone of the Project window. This function tries to minimize the latency effects of the delay compensation, while maintaining the sound of the mix as far as possible. The Delay Compensation Threshold setting is a kind of “tolerance” setting for the Constrain Delay Compensation function - only plug-ins with a delay higher than this threshold setting will be affected by the Constrain Delay Compensation function. By default, this is set to 0.0 ms, which means that all plug-ins will be affected (e. g. turned off) when you activate Constrain Delay Compensation. If you feel that a little latency is acceptable, you can raise this threshold value.”
Since “Delay Compensation Threshold” really determines the threshold for enabling/disabling plugins based on their delays, shouldn’t it be called “Plug-in Delay Threshold”?
