Ports and Outputs Ports allow each track to play up to sixteen MIDI channels and encode the record track with the channel information from MIDI Thru or from your controller(s) so that, on playback, that track always plays the same channels it was recorded on. You can also assign Ports to audio devices. Selecting an audio device as the Port changes all empty tracks from MIDI tracks to audio tracks. Select Edit Port from the Output pop-up menu to assign an audio device as the new Port. This is a great way to configure Metro to record audio (rather than MIDI tracks) as its default behavior. Metro is limited to the playback of 64 simultaneous stereo digital audio tracks (Metro SE can play 4 audio tracks). Metro Outputs only play back using one MIDI channel or audio device, unless the Output is layered. For MIDI tracks, the Metro Output’s playback channel does not have to be the same channel as the channel(s) the track was originally recorded on; it can be any channel you choose. All originally encoded channels across any given track are reassigned to the new channel(s) of the Metro Output. This allows you to reassign Output playback on the fly and also applies to audio tracks - Metro allows you to reassign the audio output device by selecting a different Metro Output. Remember that the only things that have a bearing on the data being recorded in Metro are the Record Criteria (in the Setup menu), the Record Port (in the MIDI Setup dialog box, accessible in the Setup menu), the audio record input select column in the Tracks Window and the Record Device in the Digital Audio dialog box, (in the Setup menu). See Also: Changing a Port in the Track Window Using Outputs, Ports, and Faders Using Metro Outputs Ports