Ah, I think I found the answer from the article called "Sonar: Metering options explained" from Sound on Sound. It says: In the case of the Buss meters, there's an additional option, as they can read the pre-fader/pre-effects signal, the pre-fader/post-effects signal, or the post-fader signal (which, as mentioned, reflects whatever the effects are doing). Why is this level of detail provided? Because busses often include 'send' effects such as reverb. As multiple signals may feed a buss, if an overload is occurring you need to know if it is due to excessive signal levels hitting the buss or simply a problem with an effect. (You can't simply monitor post-fader, because busses with send effects can sometimes have a fairly low output and you wouldn't 'see' any distortion.) Meter option seems to be on the toolbar, how can I access with ct? Chi