+<h2>Latency compensation</h2>
+<p>
+ During tracking it is important that the sound that is currently being
+ played back is internally aligned with the sound that is being recorded.
+</p>
+<p>
+ This is where latency-compensation comes into play. There are two ways to
+ compensate for latency in a DAW, <dfn>read-ahead</dfn> and
+ <dfn>write-behind</dfn>. The DAW starts playing a bit early (relative to
+ the playhead), so that when the sound arrives at the speakers a short time
+ later, it is exactly aligned with the material that is being recorded.
+ Since we know that play-back has latency, the incoming audio can be delayed
+ by the same amount to line things up again.
+</p>
+<p>
+ As you may see, the second approach is prone to various implementation
+ issues regarding timecode and transport synchronization. Ardour uses read-ahead
+ to compensate for latency. The time displayed in the Ardour clock corresponds
+ to the audio-signal that you hear on the speakers (and is not where Ardour
+ reads files from disk).
+</p>
+<p>
+ As a side note, this is also one of the reasons why many projects start at
+ timecode <samp>01:00:00:00</samp>. When compensating for output latency the
+ DAW will need to read data from before the start of the session, so that the
+ audio arrives in time at the output when the timecode hits <samp>01:00:00:00</samp>.
+ Ardour3 does handle the case of <samp>00:00:00:00</samp> properly but not all
+ systems/software/hardware that you may inter-operate with may behave the same.
+</p>