User Manual

UAD Powered Plug-Ins Manual - 88 - Chapter 9: UAD Delay Compensation
CHAPTER 9
UAD Delay Compensation
Latency & Delay Compensation
When UAD Powered Plug-Ins are used, audio data to be processed by a Pow-
ered Plug-In is sent by the host application to the UAD card. The audio is then
processed by the UAD card and sent back to the host application. This back-
and-forth shuffling of audio data is called “buffering” and it produces a la-
tency (delay) in the audio signal being processed.
Latency is inherent in digital audio systems and it can be detected in certain
situations. Latency time in a DAW is usually determined by the sample rate
and audio I/O interface device driver buffer size settings.
If this latency is not compensated, the processed audio will not be perfectly
synchronized with unprocessed audio. Fortunately, most audio plug-in host
applications automatically compensate for this latency when plug-ins are
used on track inserts by simply turning on the “Plug-in Delay Compensation”
(PDC) or similar Preferences setting. Many hosts even provide “Full Plug-in De-
lay Compensation” throughout the entire signal path, including sends,
groups, and buses.
UAD latency and plug-in delay compensation is managed automatically by
host applications that implement plug-in delay compensation. Additionally,
latency can be reduced to undetectable levels in the UAD-2 by bypassing host
buffering altogether (see “LiveTrack Mode” on page 76).
Host PDC Implementation
Table 6 on page 89 lists the current implementation of plug-in delay compen-
sation in the officially supported UAD host applications. The displayed ver-
sion number is the version in which PDC was implemented; higher versions
also have PDC.
Important: Delay compensation is fully automatic and requires no user in-
tervention when UAD Powered Plug-Ins are used in hosts that support “Full
plug-in Delay Compensation.”