Isadora Manual v1.3 - TroikaTronix

6) To the right of the AUMixer actor, add an DefaultOpututUnit actor. This sends
the mixed sound to the default audio output device.
7) Make a link between the AUAudioFilePlayer ‘s out 1 output and the
AULowpass’ in 1 input. Then connect the AULowpass’ out 1 output to the
AUMixer ‘s in 1 input. Finally, like the AUMixer’s out 1 output to the
DefaultOutputUnit‘s in 1 input. As soon as you make this last link, you will
hear sound. Note that the AUAudioFilePlayer and DefaultOutputUnit both have
properties called active. We will experiment with these momentarily, but suffice
to say that because both of these active properties were set to on, connecting the
last link caused sound to automatically start playing.
8) Add a Mouse Watcher to the scene. Connect the horz pos output to the cutoff
frequency input of the AULowpass, and the vert pos output the resonance
input.
9) Turn the volume of your sound system to a medium level – the low-pass filter
can make very loud sounds when the resonance is high.
10) Finally, click the start input of the Default Output Unit. You should hear your
sound playing. Moving the mouse will change the cutoff frequency and
resonance of the low-pass filter, affecting the sound’s timbre.
11) You can also experiment with changing the volume 1 and panning 1 inputs of
the AUMixer actor.
12) To mix two sounds, add another AUSoundPlayer actor to the scene, and connect
it’s out 1 output to the in 2 input of the DefaultOutputUnit. Then click the start
input of the DefaultOutputUnit. You will now hear both sounds, and can control
the volume and panning of each using the volume and panning inputs of the
AUMixer actor.
13) The DefaultOutputUnit’s active property controls the entire change of audio
actors connected to that output unit. Change this property to off you will see that
all sound will stop. Change it back to on and both sound files will start playing
again.
14) Now try changing the active property of both AUAudioFilePlayers. You will
see that you can use this property to start or stop the sound file playback
independently.
As you can see, using the CoreAudio filters to perform real-time manipulation of
sound is very much like using the video filters that have been part of Isadora since
the beginning.
Spatialized Sound - Tutorial
CoreAudio offers the ability to spatialize sound, that is, to move it in and around the
space between your speakers. Using the previous tutorial as an example.
Note that if your default audio output (as specified in the Audio MIDI Setup
application) is stereo (i.e. two speakers), the AUMixer3D will simulate movement
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