Quickly Customize Your Playback Settings
Software: Apple FCP X
To review your edit in FCP X, there are a lot more options than just pressing the Spacebar. They are found in View > Playback.
Try Play Around (Shortcut: Shift + ?). This plays from a few seconds before the current playhead (or skimmer) position to a few seconds after it. You can change the default Pre-Roll and Post-Roll settings by going to Preference > Playback.