10.6

287Logic Pro Effects
Use Synthesized IR mode
In Synthesized IR mode, Space Designer generates a synthesized impulse response based
on the values of the Length, Envelope, Filter, EQ, and Spread parameters.
Note: You can switch between a loaded impulse response sample and a synthesized
impulse response without losing the settings of the other.
• In Logic Pro, click the Synthesized IR button above the main display.
Repeated clicks of the Synthesized IR button randomly generate new impulse
responses with slightly different reflection patterns. The current impulse response
state is saved with the setting file, including parameter and other values that represent
the IR reflection patterns and characteristics.
Note:
Clicking the Synthesized IR button while you’re in Sampled IR mode switches to
the synthesized impulse response stored with the setting.
Set the impulse response sample rate and preserve length
Changing the sample rate upward increases—or changing it downward decreases—the
frequency response (and length) of the impulse response, and to a degree the overall
sound quality of the reverb. Upward sample rate changes are of benefit only if the original
impulse response sample actually contains higher frequencies. When reducing the sample
rate, use your ears to decide if the sonic quality meets your needs.
Note: Natural room surfaces—except concrete and tiles—tend to have minimal
reflections in higher frequency ranges, making half-rate and full-rate impulse
responses sound almost identical.
• In Logic Pro, choose one of the following from the Quality pop-up menu to set the
sample rate of an impulse response:
• Lo-Fi: This setting divides the sample rate by four. If the project sample rate is
96 kHz, the impulse response sample rate is converted to 24 kHz. If the project
sample rate is 44.1 kHz, the impulse response sample rate is converted to
11.025 kHz, and so on.
• Low: This setting effectively halves the sample rate. If the project sample rate is
96 kHz, the impulse response sample rate is converted to 48 kHz. If the project
sample rate is 44.1 kHz, the impulse response sample rate is converted to
22.05 kHz, and so on.