+---
+layout: default
+title: Transport Tab
+menu_title: Transport Tab
+---
+
+<p>
+ This tab contains settings that relate to the behavior of the
+ <a href="/controlling-playback/using-the-transport-bar">Transport Bar</a>
+ and <a href="/synchronization/">Synchronization</a>.
+</p>
+
+<img src="/files/a4/a4_preferences_transport.png" alt="preferences
+transport tab"/>
+
+<ul>
+ <li>
+ <p>
+ <strong>Keep record-enable engaged on stop</strong> leaves the global
+ record-enable engaged after transport is stopped. Does not affect track
+ level record-enable which is never changed on stop.
+ </p>
+ </li>
+ <li>
+ <p>
+ <strong>Play loop is a transport mode</strong> changes the behavior of the
+ loop button, turning it into a toggle. When enabled, the loop button does
+ not start playback but forces playback to always play the loop. Looping
+ stays engaged when the transport is stopped. Playback continues where the
+ transport stopped and continues to loop.
+ </p>
+ <p>
+ When disabled, the loop button starts playing the loop but stop then
+ cancels loop playback.
+ </p>
+ </li>
+ <li>
+ <p>
+ <strong>Stop recording when an xrun occurs</strong> will stop the transport
+ when an xrun occurs during recording, ensuring no audible glitches are
+ recorded.
+ </p>
+ </li>
+ <li>
+ <p>
+ <strong>Create markers where xruns occur</strong> will create a new
+ <a href="/working-with-markers/">marker</a> when an xrun occurs during
+ recording at the location of the xrun. This marks where possible xruns
+ might produce audible glitches when stopping on xruns is disabled.
+ </p>
+ </li>
+ <li>
+ <p>
+ <strong>Stop at the end of the session</strong> causes the transport to
+ stop during playback when it reaches the end marker. Behavior during
+ recording is not changed.
+ </p>
+ </li>
+ <li>
+ <p>
+ <strong>Do seamless looping</strong> removes any clicks that might
+ otherwise be audible when the transport moves from the end of the loop
+ range back to the beginning.
+ </p>
+ </li>
+ <li>
+ <p>
+ <strong>Disable per-track record disarm while rolling</strong>, when
+ enabled, will not allow the any track's record-enable to be disarmed
+ during record, preventing accidentally stopping the recording of a take.
+ </p>
+ </li>
+ <li>
+ <p>
+ <strong>12dB gain reduction during fast-forward and fast-rewind</strong>
+ when enabled will reduce the unpleasant increase in perceived volume
+ that occurs when fast-forwarding or rewinding through some kinds of audio.
+ </p>
+ </li>
+ <li>
+ <p>
+ <strong>Sync/Slave</strong>
+ <ul>
+ <li>
+ <p>
+ <strong>External timecode source</strong> determines which external
+ source to use when Ardour is using an external synchronization
+ source. Depending on the timecode source chosen, additional
+ preference options are available.
+ </p>
+ </li>
+ <li>
+ <p>
+ <strong>Match session video frame rate to external timecode</strong>
+ controls the value of the video frame rate <em>while chasing</em>
+ an external timecode source.
+ </p>
+ <p>
+ When enabled, the session video frame rate will be changed to match
+ that of the selected external timecode source.
+ </p>
+ <p>
+ When disabled, the session video frame rate will not be changed to
+ match that of the selected external timecode source. Instead, the
+ frame rate indication in the main clock will flash red and Ardour
+ will convert between the external timecode standard and the session
+ standard.
+ </p>
+ </li>
+ <li>
+ <p>
+ <strong>Sync-lock timecode to clock</strong> can disable drift
+ compensation.
+ </p>
+ <p>
+ When enabled, Ardour will never varispeed when slaved to external
+ timecode. Sync Lock indicates that the selected external timecode
+ source shares clock-sync (Black & Burst, Wordclock, etc) with
+ the audio interface. This options disables drift compensation.
+ The transport speed is fixed at 1.0. Vari-speed LTC will be ignored
+ and cause drift.
+ </p>
+ <p>
+ When disabled, Ardour will compensate for potential drift regardless
+ if the timecode sources shares clock sync.
+ </p>
+ </li>
+ <li>
+ <p>
+ <strong>Lock to 29.9700 fps instead of 30000/1001</strong>, when
+ enabled, will force Ardour to assume the external timecode source
+ uses 29.97 fps instead of 30000/1001.
+ SMPTE 12M-1999 specifies 29.97 df as 30000/1001. The spec
+ further mentions that drop-frame timecode has an accumulated error
+ of -86 ms over a 24 hour period. Drop-frame timecode would
+ compensate exactly for an NTSC color frame rate of 30 * 0.9990 (i.e.
+ 29.970000). That is not the actual rate. However, some vendors use
+ that rate - despite it being against the specs - because the
+ variant of using exactly 29.97 fps has zero timecode drift.
+ </p>
+ </ul>
+ </p>
+ </li>
+ <li>
+ <p>
+ <strong>LTC Reader</strong> specifies which incoming port will provide
+ the LTC signal.
+ </p>
+ </li>
+ <li>
+ <strong>LTC Generator</strong>
+ <ul>
+ <li>
+ <p>
+ <strong>Enable LTC generator</strong>, when enabled Ardour will
+ output an LTC timecode signal on it's <em>LTC-out</em> port.
+ </p>
+ </li>
+ <li>
+ <p>
+ <strong>Send LTC while stopped</strong>, when enabled Ardour will
+ continue to send LTC information even while the transport (playhed) is
+ not moving.
+ </p>
+ </li>
+ <li>
+ <p>
+ <strong>LTC generator level:</strong> specifies the peak volume of
+ the generated LTC signal in dbFS. A good value is 0dBu^=-18dbFS in an
+ EBU calibrated system.
+ </p>
+ </li>
+ </ul>
+ </li>
+</ul>