Instruction Manual

258 Recording
Input Monitoring
The digital audio data buffers are read by SONAR from the Wave In driver,
processed, and then sent out to the Wave Out driver. The driver passes the
digital audio buffers through a digital-to-analog converter (DAC), where the
audio data is converted back to an analog signal.
Finally, this analog output signal is mixed with the original branch of the
input analog signal, and the summed result is presented to the sound card's
line output.
With this information in hand, let's follow a simple audio signal through the
system to understand how echoes get introduced into the input monitor
path.
Suppose you are counting "1, 2, 3" into your sound card very quickly. When
you say the first "1," this sound immediately appears in all the places
indicated in the illustration above. In other words, the analog audio signal is
pure electrical signal traveling at the speed of light, so it is immediately
present across all analog audio paths inside the sound card.
say “1”