3.5

281MainStage Effects
• Length knob and field: Adjust the length of the impulse response. This control works in
conjunction with the Size knob.
• Size knob and field: Adjust the sample rate of the loaded impulse response file, thereby
changing the perceived size of the reverb by widening or narrowing the room. Size can
also be used to preserve the original length of the impulse response when changing the
sample rate with the Quality pop-up menu.
The Size knob value has an impact on the decay because it is multiplied with the Length
knob value. To explain, a Length knob value of 100% and a Size knob value of 100%
result in a decay that is the full length of the loaded impulse response.
Use Sampled IR mode
In Sampled IR mode, SpaceDesigner loads and uses an impulse response recording of an
acoustic environment. This is convolved with the incoming audio signal to place it in the
acoustic space provided by the impulse response.
1. In MainStage, click the Sampled IR button above the main display.
When you first click the Sampled IR button, a Load impulse response window opens.
2. Choose an impulse response file from any folder.
Manage the loaded impulse responsefile
• In MainStage, click the IR Sample pop-up menu to use any of the following commands:
• Load IR: Loads an impulse response sample without changing the envelopes.
• Load IR & Init: Loads an impulse response sample and initializes the envelopes.
• Show in Finder: Opens a Finder window that shows the location of the current
impulse response.
• Open IR Utility: Opens the Impulse Response Utility window.
This application enables you to create your own impulse response files. It provides
recording, editing, and processing facilities designed specifically for this task. See
Impulse Response Utility Help in the Impulse Response Utility application for details.
All factory impulse responses are installed in the /Library/Audio/Impulse Responses/Apple
folder. Deconvolution files have an .sdir file extension.
Any mono or stereo AIFF, SDII, or WAV file can be used as an impulse response. In addition,
surround formats up to 7.1, discreet audio files, and B-format audio files that consist of a
single surround impulse response can be used.