Board Thread:General Discussion/@comment-9490823-20141023235024/@comment-34326521-20141023235845

Doppler shifts always occur, regardless of relative speed (unless said speed is null). However, our limited vision does not allow us to perceive the difference. It takes machines to do that. Doppler shifts in sound are a different issue. Those we can easily hear. So no, XLR8, Jetray, and Fasttrack won't appear blue(er) or red(der) as they move closer and further away, respectively, but the sound we hear will be different.