Outputting Bars and Tone at the Head of Your Tape
When you output your program to a tape for duplication or delivery to a broadcast
facility, you’ll typically include a 1 kHz reference tone at the beginning of the tape. The
level of this tone is supposed to indicate what the average level of your audio mix is.
For this tone to be meaningful, you must mix your audio so that the average level of
your mix matches the level of the tone. Here’s why:
 If you are duplicating the tape: Most tape duplication facilities use the reference tone
at the beginning of the tape to set the audio recording levels when copying your
master tape. If your average mix levels are too quiet or too loud relative to this tone,
the audio on the copies will be either too low or distorted, respectively.
 If you’re delivering your program for broadcast: Most broadcast facilities have very
stringent requirements about what they’ll air. If your program’s audio levels are too
hot (loud) or too soft, you might run into trouble with the broadcast engineer. In the
worst cases, they’ll return your tape to you as unsuitable for broadcast and require
you to send them a new one with proper levels.