It may seem silly to worry about mono-compatibility, particularly when stereo has been around for decades and surround sound is clearly here to stay (and modern home stereo/theater amplifiers and receivers often are capable of 6.1 or even 7.1 surround sound). But there are still people out there – in your home town, even! – that are watching and listening to TV broadcasts on a television with only a single speaker. While the new digital broadcast spec is set to go into affect in early 2009, you still need to keep your tracks mono-compatible because with all the surround sound capabilities available, an out-of-phase signal can compromise even a modest surround mix. If you have a surround sound system at home, you’ve probably encountered more than a few instances where it seems like all the audio is coming from, say, a left rear speaker. When you switch your system to stereo, you get audio back to your front speakers, but imagine how unhappy a client would be with a wildly expensive commercial that cannot be properly heard on even a basic 5.1 mix, let alone a 7.1 mix. So despite all our 21st-century gear, it’s still critical to be sure your tracks are always mono-compatible!