Most RTAS plug-ins have zero delay. However, some plug-ins (such as those with lookahead like Maxim or L1), add delay. It is important to realize, however, that Pro Tools LE always has a minimum through delay based on the H/W Buffer Size (setups>Hardware window). This setting is independent of any plug-ins and adding plug-ins does not necessarily add any additional delay above the H/W buffer value (because Pro Tools LE is a single processor system). On the other hand, if the algorithm needs to buffer up many samples before it can do processing (e.g., DINR) or needs to do lookahead (Maxim, L1), then it will add delay and this delay will NOT be compensated for. Practically speaking, Pro Tools LE does NOT have delay compensation, although in many case the plug-in delay will be zero and therefore compensation won't be necessary.