Volume control of source monitor
When looking at location shots through the source monitor i can often be blasted by camera audio. This could be a big bang on set, unexpected sounds, or someone leaving a microphone on and having loud movement sounds. This also is annoying when going through stock audio that is often very compressed and very loud. I try to not touch my volume control so that my edits are all hitting the same levels and i can get a consistent output. Having a volume control on the source monitor will allow me to keep the global audio of my system set and not have to worry about being blasted in the ear by random audio on vision or stock music.
Matt Stegner commented
The Audio Clip Mixer can be used for this. Drag the clip directly into the Source monitor then view the clip mixer. Please not that this will affect the volume of the clip as it is added to and sequence, so please take that into consideration.